Whamcloud - gitweb
LU-56 ptlrpc: svc thread starting/stopping cleanup
[fs/lustre-release.git] / lustre / ptlrpc / service.c
index 37d7bf9..e6fe4c7 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Whamcloud, Inc.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 int test_req_buffer_pressure = 0;
 CFS_MODULE_PARM(test_req_buffer_pressure, "i", int, 0444,
                 "set non-zero to put pressure on request buffer pools");
-unsigned int at_min = 0;
 CFS_MODULE_PARM(at_min, "i", int, 0644,
                 "Adaptive timeout minimum (sec)");
-unsigned int at_max = 600;
-EXPORT_SYMBOL(at_max);
 CFS_MODULE_PARM(at_max, "i", int, 0644,
                 "Adaptive timeout maximum (sec)");
-unsigned int at_history = 600;
 CFS_MODULE_PARM(at_history, "i", int, 0644,
                 "Adaptive timeouts remember the slowest event that took place "
                 "within this period (sec)");
-static int at_early_margin = 5;
 CFS_MODULE_PARM(at_early_margin, "i", int, 0644,
                 "How soon before an RPC deadline to send an early reply");
-static int at_extra = 30;
 CFS_MODULE_PARM(at_extra, "i", int, 0644,
                 "How much extra time to give with each early reply");
 
 
 /* forward ref */
-static int ptlrpc_server_post_idle_rqbds (struct ptlrpc_service *svc);
+static int ptlrpc_server_post_idle_rqbds(struct ptlrpc_service_part *svcpt);
+static void ptlrpc_hpreq_fini(struct ptlrpc_request *req);
 
 static CFS_LIST_HEAD(ptlrpc_all_services);
-spinlock_t ptlrpc_all_services_lock;
-
-static char *
-ptlrpc_alloc_request_buffer (int size)
-{
-        char *ptr;
-
-        if (size > SVC_BUF_VMALLOC_THRESHOLD)
-                OBD_VMALLOC(ptr, size);
-        else
-                OBD_ALLOC(ptr, size);
-
-        return (ptr);
-}
-
-static void
-ptlrpc_free_request_buffer (char *ptr, int size)
-{
-        if (size > SVC_BUF_VMALLOC_THRESHOLD)
-                OBD_VFREE(ptr, size);
-        else
-                OBD_FREE(ptr, size);
-}
+cfs_spinlock_t ptlrpc_all_services_lock;
 
 struct ptlrpc_request_buffer_desc *
-ptlrpc_alloc_rqbd (struct ptlrpc_service *svc)
+ptlrpc_alloc_rqbd(struct ptlrpc_service_part *svcpt)
 {
-        struct ptlrpc_request_buffer_desc *rqbd;
+       struct ptlrpc_service             *svc = svcpt->scp_service;
+       struct ptlrpc_request_buffer_desc *rqbd;
 
-        OBD_ALLOC_PTR(rqbd);
-        if (rqbd == NULL)
-                return (NULL);
+       OBD_ALLOC_PTR(rqbd);
+       if (rqbd == NULL)
+               return NULL;
 
-        rqbd->rqbd_service = svc;
+       rqbd->rqbd_svcpt = svcpt;
         rqbd->rqbd_refcount = 0;
         rqbd->rqbd_cbid.cbid_fn = request_in_callback;
         rqbd->rqbd_cbid.cbid_arg = rqbd;
         CFS_INIT_LIST_HEAD(&rqbd->rqbd_reqs);
-        rqbd->rqbd_buffer = ptlrpc_alloc_request_buffer(svc->srv_buf_size);
+        OBD_ALLOC_LARGE(rqbd->rqbd_buffer, svc->srv_buf_size);
 
         if (rqbd->rqbd_buffer == NULL) {
                 OBD_FREE_PTR(rqbd);
                 return (NULL);
         }
 
-        spin_lock(&svc->srv_lock);
-        list_add(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
-        svc->srv_nbufs++;
-        spin_unlock(&svc->srv_lock);
+       cfs_spin_lock(&svcpt->scp_lock);
+       cfs_list_add(&rqbd->rqbd_list, &svcpt->scp_rqbd_idle);
+       svcpt->scp_nrqbds_total++;
+       cfs_spin_unlock(&svcpt->scp_lock);
 
-        return (rqbd);
+       return rqbd;
 }
 
 void
-ptlrpc_free_rqbd (struct ptlrpc_request_buffer_desc *rqbd)
+ptlrpc_free_rqbd(struct ptlrpc_request_buffer_desc *rqbd)
 {
-        struct ptlrpc_service *svc = rqbd->rqbd_service;
+       struct ptlrpc_service_part *svcpt = rqbd->rqbd_svcpt;
 
-        LASSERT (rqbd->rqbd_refcount == 0);
-        LASSERT (list_empty(&rqbd->rqbd_reqs));
+       LASSERT(rqbd->rqbd_refcount == 0);
+       LASSERT(cfs_list_empty(&rqbd->rqbd_reqs));
 
-        spin_lock(&svc->srv_lock);
-        list_del(&rqbd->rqbd_list);
-        svc->srv_nbufs--;
-        spin_unlock(&svc->srv_lock);
+       cfs_spin_lock(&svcpt->scp_lock);
+       cfs_list_del(&rqbd->rqbd_list);
+       svcpt->scp_nrqbds_total--;
+       cfs_spin_unlock(&svcpt->scp_lock);
 
-        ptlrpc_free_request_buffer (rqbd->rqbd_buffer, svc->srv_buf_size);
-        OBD_FREE_PTR(rqbd);
+       OBD_FREE_LARGE(rqbd->rqbd_buffer, svcpt->scp_service->srv_buf_size);
+       OBD_FREE_PTR(rqbd);
 }
 
 int
-ptlrpc_grow_req_bufs(struct ptlrpc_service *svc)
+ptlrpc_grow_req_bufs(struct ptlrpc_service_part *svcpt)
 {
+       struct ptlrpc_service             *svc = svcpt->scp_service;
         struct ptlrpc_request_buffer_desc *rqbd;
+        int                                rc = 0;
         int                                i;
 
-        CDEBUG(D_RPCTRACE, "%s: allocate %d new %d-byte reqbufs (%d/%d left)\n",
-               svc->srv_name, svc->srv_nbuf_per_group, svc->srv_buf_size,
-               svc->srv_nrqbd_receiving, svc->srv_nbufs);
         for (i = 0; i < svc->srv_nbuf_per_group; i++) {
-                rqbd = ptlrpc_alloc_rqbd(svc);
+                /* NB: another thread might be doing this as well, we need to
+                 * make sure that it wouldn't over-allocate, see LU-1212. */
+               if (svcpt->scp_nrqbds_posted >= svc->srv_nbuf_per_group)
+                       break;
+
+               rqbd = ptlrpc_alloc_rqbd(svcpt);
 
                 if (rqbd == NULL) {
-                        CERROR ("%s: Can't allocate request buffer\n",
-                                svc->srv_name);
-                        return (-ENOMEM);
+                        CERROR("%s: Can't allocate request buffer\n",
+                               svc->srv_name);
+                        rc = -ENOMEM;
+                        break;
                 }
 
-                if (ptlrpc_server_post_idle_rqbds(svc) < 0)
-                        return (-EAGAIN);
-        }
+               if (ptlrpc_server_post_idle_rqbds(svcpt) < 0) {
+                       rc = -EAGAIN;
+                       break;
+               }
+       }
+
+       CDEBUG(D_RPCTRACE,
+              "%s: allocate %d new %d-byte reqbufs (%d/%d left), rc = %d\n",
+              svc->srv_name, i, svc->srv_buf_size,
+              svcpt->scp_nrqbds_posted, svcpt->scp_nrqbds_total, rc);
 
-        return (0);
+       return rc;
 }
 
+/**
+ * Part of Rep-Ack logic.
+ * Puts a lock and its mode into reply state assotiated to request reply.
+ */
 void
-ptlrpc_save_lock (struct ptlrpc_request *req,
-                  struct lustre_handle *lock, int mode, int no_ack)
+ptlrpc_save_lock(struct ptlrpc_request *req,
+                 struct lustre_handle *lock, int mode, int no_ack)
 {
         struct ptlrpc_reply_state *rs = req->rq_reply_state;
         int                        idx;
@@ -177,223 +167,493 @@ ptlrpc_save_lock (struct ptlrpc_request *req,
         LASSERT(rs != NULL);
         LASSERT(rs->rs_nlocks < RS_MAX_LOCKS);
 
-        idx = rs->rs_nlocks++;
-        rs->rs_locks[idx] = *lock;
-        rs->rs_modes[idx] = mode;
-        rs->rs_difficult = 1;
-        rs->rs_no_ack = !!no_ack;
+        if (req->rq_export->exp_disconnected) {
+                ldlm_lock_decref(lock, mode);
+        } else {
+                idx = rs->rs_nlocks++;
+                rs->rs_locks[idx] = *lock;
+                rs->rs_modes[idx] = mode;
+                rs->rs_difficult = 1;
+                rs->rs_no_ack = !!no_ack;
+        }
 }
 
-void
-ptlrpc_schedule_difficult_reply (struct ptlrpc_reply_state *rs)
+#ifdef __KERNEL__
+
+#define HRT_RUNNING 0
+#define HRT_STOPPING 1
+
+struct ptlrpc_hr_thread {
+        cfs_spinlock_t        hrt_lock;
+        unsigned long         hrt_flags;
+        cfs_waitq_t           hrt_wait;
+        cfs_list_t            hrt_queue;
+        cfs_completion_t      hrt_completion;
+};
+
+struct ptlrpc_hr_service {
+        int                     hr_index;
+        int                     hr_n_threads;
+        int                     hr_size;
+        struct ptlrpc_hr_thread hr_threads[0];
+};
+
+struct rs_batch {
+       cfs_list_t                      rsb_replies;
+       unsigned int                    rsb_n_replies;
+       struct ptlrpc_service_part      *rsb_svcpt;
+};
+
+/**
+ *  A pointer to per-node reply handling service.
+ */
+static struct ptlrpc_hr_service *ptlrpc_hr = NULL;
+
+/**
+ * maximum mumber of replies scheduled in one batch
+ */
+#define MAX_SCHEDULED 256
+
+/**
+ * Initialize a reply batch.
+ *
+ * \param b batch
+ */
+static void rs_batch_init(struct rs_batch *b)
+{
+        memset(b, 0, sizeof *b);
+        CFS_INIT_LIST_HEAD(&b->rsb_replies);
+}
+
+/**
+ * Choose an hr thread to dispatch requests to.
+ */
+static unsigned int get_hr_thread_index(struct ptlrpc_hr_service *hr)
+{
+        unsigned int idx;
+
+        /* Concurrent modification of hr_index w/o any spinlock
+           protection is harmless as long as the result fits
+           [0..(hr_n_threads-1)] range and each thread gets near equal
+           load. */
+        idx = hr->hr_index;
+        hr->hr_index = (idx >= hr->hr_n_threads - 1) ? 0 : idx + 1;
+        return idx;
+}
+
+/**
+ * Dispatch all replies accumulated in the batch to one from
+ * dedicated reply handling threads.
+ *
+ * \param b batch
+ */
+static void rs_batch_dispatch(struct rs_batch *b)
+{
+        if (b->rsb_n_replies != 0) {
+                struct ptlrpc_hr_service *hr = ptlrpc_hr;
+                int idx;
+
+                idx = get_hr_thread_index(hr);
+
+                cfs_spin_lock(&hr->hr_threads[idx].hrt_lock);
+                cfs_list_splice_init(&b->rsb_replies,
+                                     &hr->hr_threads[idx].hrt_queue);
+                cfs_spin_unlock(&hr->hr_threads[idx].hrt_lock);
+                cfs_waitq_signal(&hr->hr_threads[idx].hrt_wait);
+                b->rsb_n_replies = 0;
+        }
+}
+
+/**
+ * Add a reply to a batch.
+ * Add one reply object to a batch, schedule batched replies if overload.
+ *
+ * \param b batch
+ * \param rs reply
+ */
+static void rs_batch_add(struct rs_batch *b, struct ptlrpc_reply_state *rs)
+{
+       struct ptlrpc_service_part *svcpt = rs->rs_svcpt;
+
+       if (svcpt != b->rsb_svcpt || b->rsb_n_replies >= MAX_SCHEDULED) {
+               if (b->rsb_svcpt != NULL) {
+                       rs_batch_dispatch(b);
+                       cfs_spin_unlock(&b->rsb_svcpt->scp_rep_lock);
+               }
+               cfs_spin_lock(&svcpt->scp_rep_lock);
+               b->rsb_svcpt = svcpt;
+        }
+        cfs_spin_lock(&rs->rs_lock);
+        rs->rs_scheduled_ever = 1;
+        if (rs->rs_scheduled == 0) {
+                cfs_list_move(&rs->rs_list, &b->rsb_replies);
+                rs->rs_scheduled = 1;
+                b->rsb_n_replies++;
+        }
+        rs->rs_committed = 1;
+        cfs_spin_unlock(&rs->rs_lock);
+}
+
+/**
+ * Reply batch finalization.
+ * Dispatch remaining replies from the batch
+ * and release remaining spinlock.
+ *
+ * \param b batch
+ */
+static void rs_batch_fini(struct rs_batch *b)
 {
-        struct ptlrpc_service *svc = rs->rs_service;
+       if (b->rsb_svcpt != NULL) {
+               rs_batch_dispatch(b);
+               cfs_spin_unlock(&b->rsb_svcpt->scp_rep_lock);
+       }
+}
+
+#define DECLARE_RS_BATCH(b)     struct rs_batch b
+
+#else /* __KERNEL__ */
+
+#define rs_batch_init(b)        do{}while(0)
+#define rs_batch_fini(b)        do{}while(0)
+#define rs_batch_add(b, r)      ptlrpc_schedule_difficult_reply(r)
+#define DECLARE_RS_BATCH(b)
+
+#endif /* __KERNEL__ */
+
+/**
+ * Put reply state into a queue for processing because we received
+ * ACK from the client
+ */
+void ptlrpc_dispatch_difficult_reply(struct ptlrpc_reply_state *rs)
+{
+#ifdef __KERNEL__
+        struct ptlrpc_hr_service *hr = ptlrpc_hr;
+        int idx;
         ENTRY;
 
-#ifdef CONFIG_SMP
-        LASSERT (spin_is_locked (&svc->srv_lock));
+        LASSERT(cfs_list_empty(&rs->rs_list));
+
+        idx = get_hr_thread_index(hr);
+        cfs_spin_lock(&hr->hr_threads[idx].hrt_lock);
+        cfs_list_add_tail(&rs->rs_list, &hr->hr_threads[idx].hrt_queue);
+        cfs_spin_unlock(&hr->hr_threads[idx].hrt_lock);
+        cfs_waitq_signal(&hr->hr_threads[idx].hrt_wait);
+        EXIT;
+#else
+       cfs_list_add_tail(&rs->rs_list, &rs->rs_svcpt->scp_rep_queue);
 #endif
+}
+
+void
+ptlrpc_schedule_difficult_reply(struct ptlrpc_reply_state *rs)
+{
+       ENTRY;
+
+       LASSERT_SPIN_LOCKED(&rs->rs_svcpt->scp_rep_lock);
+        LASSERT_SPIN_LOCKED(&rs->rs_lock);
         LASSERT (rs->rs_difficult);
-        rs->rs_scheduled_ever = 1;              /* flag any notification attempt */
+        rs->rs_scheduled_ever = 1;  /* flag any notification attempt */
 
-        if (rs->rs_scheduled) {                  /* being set up or already notified */
+        if (rs->rs_scheduled) {     /* being set up or already notified */
                 EXIT;
                 return;
         }
 
         rs->rs_scheduled = 1;
-        list_del (&rs->rs_list);
-        list_add (&rs->rs_list, &svc->srv_reply_queue);
-        cfs_waitq_signal (&svc->srv_waitq);
+        cfs_list_del_init(&rs->rs_list);
+        ptlrpc_dispatch_difficult_reply(rs);
         EXIT;
 }
 
-void
-ptlrpc_commit_replies (struct obd_device *obd)
+void ptlrpc_commit_replies(struct obd_export *exp)
 {
-        struct list_head   *tmp;
-        struct list_head   *nxt;
+        struct ptlrpc_reply_state *rs, *nxt;
+        DECLARE_RS_BATCH(batch);
         ENTRY;
 
+        rs_batch_init(&batch);
         /* Find any replies that have been committed and get their service
          * to attend to complete them. */
 
         /* CAVEAT EMPTOR: spinlock ordering!!! */
-        spin_lock(&obd->obd_uncommitted_replies_lock);
-
-        list_for_each_safe (tmp, nxt, &obd->obd_uncommitted_replies) {
-                struct ptlrpc_reply_state *rs =
-                        list_entry(tmp, struct ptlrpc_reply_state, rs_obd_list);
-
+        cfs_spin_lock(&exp->exp_uncommitted_replies_lock);
+        cfs_list_for_each_entry_safe(rs, nxt, &exp->exp_uncommitted_replies,
+                                     rs_obd_list) {
                 LASSERT (rs->rs_difficult);
-
-                if (rs->rs_transno <= obd->obd_last_committed) {
-                        struct ptlrpc_service *svc = rs->rs_service;
-
-                        spin_lock (&svc->srv_lock);
-                        list_del_init (&rs->rs_obd_list);
-                        ptlrpc_schedule_difficult_reply (rs);
-                        spin_unlock (&svc->srv_lock);
+                /* VBR: per-export last_committed */
+                LASSERT(rs->rs_export);
+                if (rs->rs_transno <= exp->exp_last_committed) {
+                        cfs_list_del_init(&rs->rs_obd_list);
+                        rs_batch_add(&batch, rs);
                 }
         }
-
-        spin_unlock(&obd->obd_uncommitted_replies_lock);
+        cfs_spin_unlock(&exp->exp_uncommitted_replies_lock);
+        rs_batch_fini(&batch);
         EXIT;
 }
 
 static int
-ptlrpc_server_post_idle_rqbds (struct ptlrpc_service *svc)
+ptlrpc_server_post_idle_rqbds(struct ptlrpc_service_part *svcpt)
 {
-        struct ptlrpc_request_buffer_desc *rqbd;
-        int                                rc;
-        int                                posted = 0;
+       struct ptlrpc_request_buffer_desc *rqbd;
+       int                               rc;
+       int                               posted = 0;
 
-        for (;;) {
-                spin_lock(&svc->srv_lock);
+       for (;;) {
+               cfs_spin_lock(&svcpt->scp_lock);
 
-                if (list_empty (&svc->srv_idle_rqbds)) {
-                        spin_unlock(&svc->srv_lock);
-                        return (posted);
-                }
+               if (cfs_list_empty(&svcpt->scp_rqbd_idle)) {
+                       cfs_spin_unlock(&svcpt->scp_lock);
+                       return posted;
+               }
 
-                rqbd = list_entry(svc->srv_idle_rqbds.next,
-                                  struct ptlrpc_request_buffer_desc,
-                                  rqbd_list);
-                list_del (&rqbd->rqbd_list);
+               rqbd = cfs_list_entry(svcpt->scp_rqbd_idle.next,
+                                     struct ptlrpc_request_buffer_desc,
+                                     rqbd_list);
+               cfs_list_del(&rqbd->rqbd_list);
 
-                /* assume we will post successfully */
-                svc->srv_nrqbd_receiving++;
-                list_add (&rqbd->rqbd_list, &svc->srv_active_rqbds);
+               /* assume we will post successfully */
+               svcpt->scp_nrqbds_posted++;
+               cfs_list_add(&rqbd->rqbd_list, &svcpt->scp_rqbd_posted);
 
-                spin_unlock(&svc->srv_lock);
+               cfs_spin_unlock(&svcpt->scp_lock);
 
-                rc = ptlrpc_register_rqbd(rqbd);
-                if (rc != 0)
-                        break;
+               rc = ptlrpc_register_rqbd(rqbd);
+               if (rc != 0)
+                       break;
 
-                posted = 1;
-        }
+               posted = 1;
+       }
+
+       cfs_spin_lock(&svcpt->scp_lock);
+
+       svcpt->scp_nrqbds_posted--;
+       cfs_list_del(&rqbd->rqbd_list);
+       cfs_list_add_tail(&rqbd->rqbd_list, &svcpt->scp_rqbd_idle);
 
-        spin_lock(&svc->srv_lock);
+       /* Don't complain if no request buffers are posted right now; LNET
+        * won't drop requests because we set the portal lazy! */
 
-        svc->srv_nrqbd_receiving--;
-        list_del(&rqbd->rqbd_list);
-        list_add_tail(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
+       cfs_spin_unlock(&svcpt->scp_lock);
 
-        /* Don't complain if no request buffers are posted right now; LNET
-         * won't drop requests because we set the portal lazy! */
+       return -1;
+}
+
+static void ptlrpc_at_timer(unsigned long castmeharder)
+{
+       struct ptlrpc_service_part *svcpt;
 
-        spin_unlock(&svc->srv_lock);
+       svcpt = (struct ptlrpc_service_part *)castmeharder;
 
-        return (-1);
+       svcpt->scp_at_check = 1;
+       svcpt->scp_at_checktime = cfs_time_current();
+       cfs_waitq_signal(&svcpt->scp_waitq);
 }
 
-struct ptlrpc_service *ptlrpc_init_svc_conf(struct ptlrpc_service_conf *c,
-                                            svc_handler_t h, char *name,
-                                            struct proc_dir_entry *proc_entry,
-                                            svcreq_printfn_t prntfn,
-                                            char *threadname)
+static void
+ptlrpc_server_nthreads_check(struct ptlrpc_service_conf *conf,
+                            int *min_p, int *max_p)
 {
-        return ptlrpc_init_svc(c->psc_nbufs, c->psc_bufsize,
-                               c->psc_max_req_size, c->psc_max_reply_size,
-                               c->psc_req_portal, c->psc_rep_portal,
-                               c->psc_watchdog_factor,
-                               h, name, proc_entry,
-                               prntfn, c->psc_min_threads, c->psc_max_threads,
-                               threadname, c->psc_ctx_tags);
+#ifdef __KERNEL__
+       struct ptlrpc_service_thr_conf  *tc = &conf->psc_thr;
+       int                             nthrs_min;
+       int                             nthrs;
+
+       nthrs_min = PTLRPC_NTHRS_MIN + (conf->psc_ops.so_hpreq_handler != NULL);
+       nthrs_min = max_t(int, nthrs_min, tc->tc_nthrs_min);
+
+       nthrs = tc->tc_nthrs_user;
+       if (nthrs != 0) { /* validate it */
+               nthrs = min_t(int, nthrs, tc->tc_nthrs_max);
+               nthrs = max_t(int, nthrs, nthrs_min);
+               *min_p = *max_p = nthrs;
+               return;
+       }
+
+       /*
+        * NB: we will add some common code here for estimating, for example:
+        * add a new member ptlrpc_service_thr_conf::tc_factor, and estimate
+        * threads number based on:
+        *     (online_cpus * conf::tc_factor) + conf::tc_nthrs_base.
+        *
+        * So we can remove code block like estimation in ost_setup, also,
+        * we might estimate MDS threads number as well instead of using
+        * absolute number, and have more threads on fat servers to improve
+        * availability of service.
+        *
+        * Also, we will need to validate threads number at here for
+        * CPT affinity service (CPU ParTion) in the future.
+        * A service can have percpt thread-pool instead of a global thread
+        * pool for each service, which means user might not always get the
+        * threads number they want even they set it in conf::tc_nthrs_user,
+        * because we need to adjust threads number for each CPT, instead of
+        * just use (conf::tc_nthrs_user / NCPTS), to make sure each pool
+        * will be healthy.
+        */
+       *max_p = tc->tc_nthrs_max;
+       *min_p = nthrs_min;
+#else /* __KERNEL__ */
+       *max_p = *min_p = 1; /* whatever */
+#endif
 }
-EXPORT_SYMBOL(ptlrpc_init_svc_conf);
 
-static void ptlrpc_at_timer(unsigned long castmeharder)
+/**
+ * Initialize percpt data for a service
+ */
+static int
+ptlrpc_service_part_init(struct ptlrpc_service *svc,
+                        struct ptlrpc_service_part *svcpt)
 {
-        struct ptlrpc_service *svc = (struct ptlrpc_service *)castmeharder;
-        svc->srv_at_check = 1;
-        svc->srv_at_checktime = cfs_time_current();
-        cfs_waitq_signal(&svc->srv_waitq);
+       struct ptlrpc_at_array  *array;
+       int                     size;
+       int                     index;
+       int                     rc;
+
+       CFS_INIT_LIST_HEAD(&svcpt->scp_threads);
+
+       /* rqbd and incoming request queue */
+       cfs_spin_lock_init(&svcpt->scp_lock);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_rqbd_idle);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_rqbd_posted);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_req_incoming);
+       cfs_waitq_init(&svcpt->scp_waitq);
+       /* history request & rqbd list */
+       CFS_INIT_LIST_HEAD(&svcpt->scp_hist_reqs);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_hist_rqbds);
+
+       /* acitve requests and hp requests */
+       cfs_spin_lock_init(&svcpt->scp_req_lock);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_req_pending);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_hreq_pending);
+
+       /* reply states */
+       cfs_spin_lock_init(&svcpt->scp_rep_lock);
+       CFS_INIT_LIST_HEAD(&svcpt->scp_rep_active);
+#ifndef __KERNEL__
+       CFS_INIT_LIST_HEAD(&svcpt->scp_rep_queue);
+#endif
+       CFS_INIT_LIST_HEAD(&svcpt->scp_rep_idle);
+       cfs_waitq_init(&svcpt->scp_rep_waitq);
+       cfs_atomic_set(&svcpt->scp_nreps_difficult, 0);
+
+       /* adaptive timeout */
+       cfs_spin_lock_init(&svcpt->scp_at_lock);
+       array = &svcpt->scp_at_array;
+
+       size = at_est2timeout(at_max);
+       array->paa_size     = size;
+       array->paa_count    = 0;
+       array->paa_deadline = -1;
+
+       /* allocate memory for scp_at_array (ptlrpc_at_array) */
+       OBD_ALLOC(array->paa_reqs_array, sizeof(cfs_list_t) * size);
+       if (array->paa_reqs_array == NULL)
+               return -ENOMEM;
+
+       for (index = 0; index < size; index++)
+               CFS_INIT_LIST_HEAD(&array->paa_reqs_array[index]);
+
+       OBD_ALLOC(array->paa_reqs_count, sizeof(__u32) * size);
+       if (array->paa_reqs_count == NULL)
+               goto failed;
+
+       cfs_timer_init(&svcpt->scp_at_timer, ptlrpc_at_timer, svcpt);
+       /* At SOW, service time should be quick; 10s seems generous. If client
+        * timeout is less than this, we'll be sending an early reply. */
+       at_init(&svcpt->scp_at_estimate, 10, 0);
+
+       /* assign this before call ptlrpc_grow_req_bufs */
+       svcpt->scp_service = svc;
+       /* Now allocate the request buffers, but don't post them now */
+       rc = ptlrpc_grow_req_bufs(svcpt);
+       /* We shouldn't be under memory pressure at startup, so
+        * fail if we can't allocate all our buffers at this time. */
+       if (rc != 0)
+               goto failed;
+
+       return 0;
+
+ failed:
+       if (array->paa_reqs_count != NULL) {
+               OBD_FREE(array->paa_reqs_count, sizeof(__u32) * size);
+               array->paa_reqs_count = NULL;
+       }
+
+       if (array->paa_reqs_array != NULL) {
+               OBD_FREE(array->paa_reqs_array,
+                        sizeof(cfs_list_t) * array->paa_size);
+               array->paa_reqs_array = NULL;
+       }
+
+       return -ENOMEM;
 }
 
-/* @threadname should be 11 characters or less - 3 will be added on */
+/**
+ * Initialize service on a given portal.
+ * This includes starting serving threads , allocating and posting rqbds and
+ * so on.
+ */
 struct ptlrpc_service *
-ptlrpc_init_svc(int nbufs, int bufsize, int max_req_size, int max_reply_size,
-                int req_portal, int rep_portal, int watchdog_factor,
-                svc_handler_t handler, char *name,
-                cfs_proc_dir_entry_t *proc_entry,
-                svcreq_printfn_t svcreq_printfn,
-                int min_threads, int max_threads,
-                char *threadname, __u32 ctx_tags)
+ptlrpc_register_service(struct ptlrpc_service_conf *conf,
+                       cfs_proc_dir_entry_t *proc_entry)
 {
-        int                    rc;
-        struct ptlrpc_service *service;
-        ENTRY;
-
-        LASSERT (nbufs > 0);
-        LASSERT (bufsize >= max_req_size + SPTLRPC_MAX_PAYLOAD);
-        LASSERT (ctx_tags != 0);
-
-        OBD_ALLOC_PTR(service);
-        if (service == NULL)
-                RETURN(NULL);
-
-        /* First initialise enough for early teardown */
-
-        service->srv_name = name;
-        spin_lock_init(&service->srv_lock);
-        CFS_INIT_LIST_HEAD(&service->srv_threads);
-        cfs_waitq_init(&service->srv_waitq);
-
-        service->srv_nbuf_per_group = test_req_buffer_pressure ? 1 : nbufs;
-        service->srv_max_req_size = max_req_size + SPTLRPC_MAX_PAYLOAD;
-        service->srv_buf_size = bufsize;
-        service->srv_rep_portal = rep_portal;
-        service->srv_req_portal = req_portal;
-        service->srv_watchdog_factor = watchdog_factor;
-        service->srv_handler = handler;
-        service->srv_request_history_print_fn = svcreq_printfn;
-        service->srv_request_seq = 1;           /* valid seq #s start at 1 */
-        service->srv_request_max_cull_seq = 0;
-        service->srv_threads_min = min_threads;
-        service->srv_threads_max = max_threads;
-        service->srv_thread_name = threadname;
-        service->srv_ctx_tags = ctx_tags;
-
-        rc = LNetSetLazyPortal(service->srv_req_portal);
-        LASSERT (rc == 0);
-
-        CFS_INIT_LIST_HEAD(&service->srv_request_queue);
-        CFS_INIT_LIST_HEAD(&service->srv_idle_rqbds);
-        CFS_INIT_LIST_HEAD(&service->srv_active_rqbds);
-        CFS_INIT_LIST_HEAD(&service->srv_history_rqbds);
-        CFS_INIT_LIST_HEAD(&service->srv_request_history);
-        CFS_INIT_LIST_HEAD(&service->srv_active_replies);
-        CFS_INIT_LIST_HEAD(&service->srv_reply_queue);
-        CFS_INIT_LIST_HEAD(&service->srv_free_rs_list);
-        cfs_waitq_init(&service->srv_free_rs_waitq);
-
-        spin_lock_init(&service->srv_at_lock);
-        CFS_INIT_LIST_HEAD(&service->srv_req_in_queue);
-        CFS_INIT_LIST_HEAD(&service->srv_at_list);
-        cfs_timer_init(&service->srv_at_timer, ptlrpc_at_timer, service);
-        /* At SOW, service time should be quick; 10s seems generous. If client
-           timeout is less than this, we'll be sending an early reply. */
-        at_init(&service->srv_at_estimate, 10, 0);
-
-        spin_lock (&ptlrpc_all_services_lock);
-        list_add (&service->srv_list, &ptlrpc_all_services);
-        spin_unlock (&ptlrpc_all_services_lock);
-
-        /* Now allocate the request buffers */
-        rc = ptlrpc_grow_req_bufs(service);
-        /* We shouldn't be under memory pressure at startup, so
-         * fail if we can't post all our buffers at this time. */
-        if (rc != 0)
-                GOTO(failed, NULL);
-
-        /* Now allocate pool of reply buffers */
-        /* Increase max reply size to next power of two */
-        service->srv_max_reply_size = 1;
-        while (service->srv_max_reply_size <
-               max_reply_size + SPTLRPC_MAX_PAYLOAD)
-                service->srv_max_reply_size <<= 1;
+       struct ptlrpc_service           *service;
+       int                             rc;
+       ENTRY;
+
+       LASSERT(conf->psc_buf.bc_nbufs > 0);
+       LASSERT(conf->psc_buf.bc_buf_size >=
+               conf->psc_buf.bc_req_max_size + SPTLRPC_MAX_PAYLOAD);
+       LASSERT(conf->psc_thr.tc_ctx_tags != 0);
+
+       OBD_ALLOC_PTR(service);
+       if (service == NULL)
+               RETURN(ERR_PTR(-ENOMEM));
+
+       /* public members */
+       cfs_spin_lock_init(&service->srv_lock);
+       service->srv_name               = conf->psc_name;
+       service->srv_watchdog_factor    = conf->psc_watchdog_factor;
+       CFS_INIT_LIST_HEAD(&service->srv_list); /* for safty of cleanup */
+
+       /* buffer configuration */
+       service->srv_nbuf_per_group     = test_req_buffer_pressure ?
+                                         1 : conf->psc_buf.bc_nbufs;
+       service->srv_max_req_size       = conf->psc_buf.bc_req_max_size +
+                                         SPTLRPC_MAX_PAYLOAD;
+       service->srv_buf_size           = conf->psc_buf.bc_buf_size;
+       service->srv_rep_portal         = conf->psc_buf.bc_rep_portal;
+       service->srv_req_portal         = conf->psc_buf.bc_req_portal;
+
+       /* Increase max reply size to next power of two */
+       service->srv_max_reply_size = 1;
+       while (service->srv_max_reply_size <
+              conf->psc_buf.bc_rep_max_size + SPTLRPC_MAX_PAYLOAD)
+               service->srv_max_reply_size <<= 1;
+
+       ptlrpc_server_nthreads_check(conf, &service->srv_threads_min,
+                                    &service->srv_threads_max);
+
+       service->srv_thread_name        = conf->psc_thr.tc_thr_name;
+       service->srv_ctx_tags           = conf->psc_thr.tc_ctx_tags;
+       service->srv_cpu_affinity       = !!conf->psc_thr.tc_cpu_affinity;
+       service->srv_hpreq_ratio        = PTLRPC_SVC_HP_RATIO;
+       service->srv_ops                = conf->psc_ops;
+
+       OBD_ALLOC_PTR(service->srv_part);
+       if (service->srv_part == NULL)
+               GOTO(failed, rc = -ENOMEM);
+
+       rc = ptlrpc_service_part_init(service, service->srv_part);
+       if (rc != 0)
+               GOTO(failed, rc);
+
+       rc = LNetSetLazyPortal(service->srv_req_portal);
+       LASSERT(rc == 0);
+
+        cfs_spin_lock (&ptlrpc_all_services_lock);
+        cfs_list_add (&service->srv_list, &ptlrpc_all_services);
+        cfs_spin_unlock (&ptlrpc_all_services_lock);
 
         if (proc_entry != NULL)
                 ptlrpc_lprocfs_register_service(proc_entry, service);
@@ -401,10 +661,19 @@ ptlrpc_init_svc(int nbufs, int bufsize, int max_req_size, int max_reply_size,
         CDEBUG(D_NET, "%s: Started, listening on portal %d\n",
                service->srv_name, service->srv_req_portal);
 
-        RETURN(service);
+#ifdef __KERNEL__
+       rc = ptlrpc_start_threads(service);
+       if (rc != 0) {
+               CERROR("Failed to start threads for service %s: %d\n",
+                      service->srv_name, rc);
+               GOTO(failed, rc);
+       }
+#endif
+
+       RETURN(service);
 failed:
-        ptlrpc_unregister_service(service);
-        return NULL;
+       ptlrpc_unregister_service(service);
+       RETURN(ERR_PTR(rc));
 }
 
 /**
@@ -413,8 +682,8 @@ failed:
  */
 static void ptlrpc_server_free_request(struct ptlrpc_request *req)
 {
-        LASSERT(atomic_read(&req->rq_refcount) == 0);
-        LASSERT(list_empty(&req->rq_timed_list));
+        LASSERT(cfs_atomic_read(&req->rq_refcount) == 0);
+        LASSERT(cfs_list_empty(&req->rq_timed_list));
 
          /* DEBUG_REQ() assumes the reply state of a request with a valid
           * ref will not be destroyed until that reference is dropped. */
@@ -434,110 +703,139 @@ static void ptlrpc_server_free_request(struct ptlrpc_request *req)
  * drop a reference count of the request. if it reaches 0, we either
  * put it into history list, or free it immediately.
  */
-static void ptlrpc_server_drop_request(struct ptlrpc_request *req)
+void ptlrpc_server_drop_request(struct ptlrpc_request *req)
 {
-        struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
-        struct ptlrpc_service             *svc = rqbd->rqbd_service;
+       struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
+       struct ptlrpc_service_part        *svcpt = rqbd->rqbd_svcpt;
+       struct ptlrpc_service             *svc = svcpt->scp_service;
         int                                refcount;
-        struct list_head                  *tmp;
-        struct list_head                  *nxt;
+        cfs_list_t                        *tmp;
+        cfs_list_t                        *nxt;
 
-        if (!atomic_dec_and_test(&req->rq_refcount))
+        if (!cfs_atomic_dec_and_test(&req->rq_refcount))
                 return;
 
-        spin_lock(&svc->srv_lock);
+       cfs_spin_lock(&svcpt->scp_at_lock);
+       if (req->rq_at_linked) {
+               struct ptlrpc_at_array *array = &svcpt->scp_at_array;
+                __u32 index = req->rq_at_index;
 
-        svc->srv_n_active_reqs--;
-        list_add(&req->rq_list, &rqbd->rqbd_reqs);
+                LASSERT(!cfs_list_empty(&req->rq_timed_list));
+                cfs_list_del_init(&req->rq_timed_list);
+                cfs_spin_lock(&req->rq_lock);
+                req->rq_at_linked = 0;
+                cfs_spin_unlock(&req->rq_lock);
+                array->paa_reqs_count[index]--;
+                array->paa_count--;
+        } else
+                LASSERT(cfs_list_empty(&req->rq_timed_list));
+
+       cfs_spin_unlock(&svcpt->scp_at_lock);
+
+        /* finalize request */
+        if (req->rq_export) {
+                class_export_put(req->rq_export);
+                req->rq_export = NULL;
+        }
+
+       cfs_spin_lock(&svcpt->scp_lock);
+
+        cfs_list_add(&req->rq_list, &rqbd->rqbd_reqs);
 
         refcount = --(rqbd->rqbd_refcount);
         if (refcount == 0) {
                 /* request buffer is now idle: add to history */
-                list_del(&rqbd->rqbd_list);
-                list_add_tail(&rqbd->rqbd_list, &svc->srv_history_rqbds);
-                svc->srv_n_history_rqbds++;
+                cfs_list_del(&rqbd->rqbd_list);
+
+               cfs_list_add_tail(&rqbd->rqbd_list, &svcpt->scp_hist_rqbds);
+               svcpt->scp_hist_nrqbds++;
 
-                /* cull some history?
-                 * I expect only about 1 or 2 rqbds need to be recycled here */
-                while (svc->srv_n_history_rqbds > svc->srv_max_history_rqbds) {
-                        rqbd = list_entry(svc->srv_history_rqbds.next,
-                                          struct ptlrpc_request_buffer_desc,
-                                          rqbd_list);
+               /* cull some history?
+                * I expect only about 1 or 2 rqbds need to be recycled here */
+               while (svcpt->scp_hist_nrqbds > svc->srv_max_history_rqbds) {
+                       rqbd = cfs_list_entry(svcpt->scp_hist_rqbds.next,
+                                             struct ptlrpc_request_buffer_desc,
+                                             rqbd_list);
 
-                        list_del(&rqbd->rqbd_list);
-                        svc->srv_n_history_rqbds--;
+                       cfs_list_del(&rqbd->rqbd_list);
+                       svcpt->scp_hist_nrqbds--;
 
                         /* remove rqbd's reqs from svc's req history while
                          * I've got the service lock */
-                        list_for_each(tmp, &rqbd->rqbd_reqs) {
-                                req = list_entry(tmp, struct ptlrpc_request,
-                                                 rq_list);
+                        cfs_list_for_each(tmp, &rqbd->rqbd_reqs) {
+                                req = cfs_list_entry(tmp, struct ptlrpc_request,
+                                                     rq_list);
                                 /* Track the highest culled req seq */
-                                if (req->rq_history_seq >
-                                    svc->srv_request_max_cull_seq)
-                                        svc->srv_request_max_cull_seq =
-                                                req->rq_history_seq;
-                                list_del(&req->rq_history_list);
-                        }
-
-                        spin_unlock(&svc->srv_lock);
-
-                        list_for_each_safe(tmp, nxt, &rqbd->rqbd_reqs) {
-                                req = list_entry(rqbd->rqbd_reqs.next,
-                                                 struct ptlrpc_request,
-                                                 rq_list);
-                                list_del(&req->rq_list);
+                               if (req->rq_history_seq >
+                                   svcpt->scp_hist_seq_culled) {
+                                       svcpt->scp_hist_seq_culled =
+                                               req->rq_history_seq;
+                               }
+                               cfs_list_del(&req->rq_history_list);
+                       }
+
+                       cfs_spin_unlock(&svcpt->scp_lock);
+
+                        cfs_list_for_each_safe(tmp, nxt, &rqbd->rqbd_reqs) {
+                                req = cfs_list_entry(rqbd->rqbd_reqs.next,
+                                                     struct ptlrpc_request,
+                                                     rq_list);
+                                cfs_list_del(&req->rq_list);
                                 ptlrpc_server_free_request(req);
                         }
 
-                        spin_lock(&svc->srv_lock);
-                        /*
-                         * now all reqs including the embedded req has been
-                         * disposed, schedule request buffer for re-use.
-                         */
-                        LASSERT(atomic_read(&rqbd->rqbd_req.rq_refcount) == 0);
-                        list_add_tail(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
-                }
-
-                spin_unlock(&svc->srv_lock);
-        } else if (req->rq_reply_state && req->rq_reply_state->rs_prealloc) {
-                /* If we are low on memory, we are not interested in history */
-                list_del(&req->rq_list);
-                list_del_init(&req->rq_history_list);
-                spin_unlock(&svc->srv_lock);
-
-                ptlrpc_server_free_request(req);
-        } else {
-                spin_unlock(&svc->srv_lock);
-        }
+                       cfs_spin_lock(&svcpt->scp_lock);
+                       /*
+                        * now all reqs including the embedded req has been
+                        * disposed, schedule request buffer for re-use.
+                        */
+                       LASSERT(cfs_atomic_read(&rqbd->rqbd_req.rq_refcount) ==
+                               0);
+                       cfs_list_add_tail(&rqbd->rqbd_list,
+                                         &svcpt->scp_rqbd_idle);
+               }
+
+               cfs_spin_unlock(&svcpt->scp_lock);
+       } else if (req->rq_reply_state && req->rq_reply_state->rs_prealloc) {
+               /* If we are low on memory, we are not interested in history */
+               cfs_list_del(&req->rq_list);
+               cfs_list_del_init(&req->rq_history_list);
+
+               cfs_spin_unlock(&svcpt->scp_lock);
+
+               ptlrpc_server_free_request(req);
+       } else {
+               cfs_spin_unlock(&svcpt->scp_lock);
+       }
 }
 
 /**
  * to finish a request: stop sending more early replies, and release
  * the request. should be called after we finished handling the request.
  */
-static void ptlrpc_server_finish_request(struct ptlrpc_request *req)
+static void ptlrpc_server_finish_request(struct ptlrpc_service_part *svcpt,
+                                        struct ptlrpc_request *req)
 {
-        struct ptlrpc_service  *svc = req->rq_rqbd->rqbd_service;
+       ptlrpc_hpreq_fini(req);
 
-        if (req->rq_phase != RQ_PHASE_NEW) /* incorrect message magic */
-                DEBUG_REQ(D_INFO, req, "free req");
+       cfs_spin_lock(&svcpt->scp_req_lock);
+       svcpt->scp_nreqs_active--;
+       if (req->rq_hp)
+               svcpt->scp_nhreqs_active--;
+       cfs_spin_unlock(&svcpt->scp_req_lock);
 
-        spin_lock(&svc->srv_at_lock);
-        req->rq_sent_final = 1;
-        list_del_init(&req->rq_timed_list);
-        spin_unlock(&svc->srv_at_lock);
-
-        ptlrpc_server_drop_request(req);
+       ptlrpc_server_drop_request(req);
 }
 
-/* This function makes sure dead exports are evicted in a timely manner.
-   This function is only called when some export receives a message (i.e.,
-   the network is up.) */
+/**
+ * This function makes sure dead exports are evicted in a timely manner.
+ * This function is only called when some export receives a message (i.e.,
+ * the network is up.)
+ */
 static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
 {
         struct obd_export *oldest_exp;
-        time_t oldest_time;
+        time_t oldest_time, new_time;
 
         ENTRY;
 
@@ -548,9 +846,13 @@ static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
            of the list, we can be really lazy here - we don't have to evict
            at the exact right moment.  Eventually, all silent exports
            will make it to the top of the list. */
-        exp->exp_last_request_time = max(exp->exp_last_request_time,
-                                         cfs_time_current_sec() + extra_delay);
 
+        /* Do not pay attention on 1sec or smaller renewals. */
+        new_time = cfs_time_current_sec() + extra_delay;
+        if (exp->exp_last_request_time + 1 /*second */ >= new_time)
+                RETURN_EXIT;
+
+        exp->exp_last_request_time = new_time;
         CDEBUG(D_HA, "updating export %s at "CFS_TIME_T" exp %p\n",
                exp->exp_client_uuid.uuid,
                exp->exp_last_request_time, exp);
@@ -558,22 +860,21 @@ static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
         /* exports may get disconnected from the chain even though the
            export has references, so we must keep the spin lock while
            manipulating the lists */
-        spin_lock(&exp->exp_obd->obd_dev_lock);
+        cfs_spin_lock(&exp->exp_obd->obd_dev_lock);
 
-        if (list_empty(&exp->exp_obd_chain_timed)) {
+        if (cfs_list_empty(&exp->exp_obd_chain_timed)) {
                 /* this one is not timed */
-                spin_unlock(&exp->exp_obd->obd_dev_lock);
-                EXIT;
-                return;
+                cfs_spin_unlock(&exp->exp_obd->obd_dev_lock);
+                RETURN_EXIT;
         }
 
-        list_move_tail(&exp->exp_obd_chain_timed,
-                       &exp->exp_obd->obd_exports_timed);
+        cfs_list_move_tail(&exp->exp_obd_chain_timed,
+                           &exp->exp_obd->obd_exports_timed);
 
-        oldest_exp = list_entry(exp->exp_obd->obd_exports_timed.next,
-                                struct obd_export, exp_obd_chain_timed);
+        oldest_exp = cfs_list_entry(exp->exp_obd->obd_exports_timed.next,
+                                    struct obd_export, exp_obd_chain_timed);
         oldest_time = oldest_exp->exp_last_request_time;
-        spin_unlock(&exp->exp_obd->obd_dev_lock);
+        cfs_spin_unlock(&exp->exp_obd->obd_dev_lock);
 
         if (exp->exp_obd->obd_recovering) {
                 /* be nice to everyone during recovery */
@@ -593,8 +894,8 @@ static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
                         exp->exp_obd->obd_eviction_timer =
                                 cfs_time_current_sec() + 3 * PING_INTERVAL;
                         CDEBUG(D_HA, "%s: Think about evicting %s from "CFS_TIME_T"\n",
-                               exp->exp_obd->obd_name, obd_export_nid2str(exp),
-                               oldest_time);
+                               exp->exp_obd->obd_name, 
+                               obd_export_nid2str(oldest_exp), oldest_time);
                 }
         } else {
                 if (cfs_time_current_sec() >
@@ -610,8 +911,14 @@ static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
         EXIT;
 }
 
+/**
+ * Sanity check request \a req.
+ * Return 0 if all is ok, error code otherwise.
+ */
 static int ptlrpc_check_req(struct ptlrpc_request *req)
 {
+        int rc = 0;
+
         if (unlikely(lustre_msg_get_conn_cnt(req->rq_reqmsg) <
                      req->rq_export->exp_conn_cnt)) {
                 DEBUG_REQ(D_ERROR, req,
@@ -626,44 +933,62 @@ static int ptlrpc_check_req(struct ptlrpc_request *req)
                 error response instead. */
                 CDEBUG(D_RPCTRACE, "Dropping req %p for failed obd %s\n",
                        req, req->rq_export->exp_obd->obd_name);
-                req->rq_status = -ENODEV;
+                rc = -ENODEV;
+        } else if (lustre_msg_get_flags(req->rq_reqmsg) &
+                   (MSG_REPLAY | MSG_REQ_REPLAY_DONE) &&
+                   !(req->rq_export->exp_obd->obd_recovering)) {
+                        DEBUG_REQ(D_ERROR, req,
+                                  "Invalid replay without recovery");
+                        class_fail_export(req->rq_export);
+                        rc = -ENODEV;
+        } else if (lustre_msg_get_transno(req->rq_reqmsg) != 0 &&
+                   !(req->rq_export->exp_obd->obd_recovering)) {
+                        DEBUG_REQ(D_ERROR, req, "Invalid req with transno "
+                                  LPU64" without recovery",
+                                  lustre_msg_get_transno(req->rq_reqmsg));
+                        class_fail_export(req->rq_export);
+                        rc = -ENODEV;
+        }
+
+        if (unlikely(rc < 0)) {
+                req->rq_status = rc;
                 ptlrpc_error(req);
-                return -ENODEV;
         }
-
-        return 0;
+        return rc;
 }
 
-static void ptlrpc_at_set_timer(struct ptlrpc_service *svc)
+static void ptlrpc_at_set_timer(struct ptlrpc_service_part *svcpt)
 {
-        struct ptlrpc_request *rq;
-        __s32 next;
-
-        spin_lock(&svc->srv_at_lock);
-        if (list_empty(&svc->srv_at_list)) {
-                cfs_timer_disarm(&svc->srv_at_timer);
-                spin_unlock(&svc->srv_at_lock);
-                return;
-        }
-
-        /* Set timer for closest deadline */
-        rq = list_entry(svc->srv_at_list.next, struct ptlrpc_request,
-                        rq_timed_list);
-        next = (__s32)(rq->rq_deadline - cfs_time_current_sec() -
-                       at_early_margin);
-        if (next <= 0)
-                ptlrpc_at_timer((unsigned long)svc);
-        else
-                cfs_timer_arm(&svc->srv_at_timer, cfs_time_shift(next));
-        spin_unlock(&svc->srv_at_lock);
-        CDEBUG(D_INFO, "armed %s at %+ds\n", svc->srv_name, next);
+       struct ptlrpc_at_array *array = &svcpt->scp_at_array;
+       __s32 next;
+
+       cfs_spin_lock(&svcpt->scp_at_lock);
+       if (array->paa_count == 0) {
+               cfs_timer_disarm(&svcpt->scp_at_timer);
+               cfs_spin_unlock(&svcpt->scp_at_lock);
+               return;
+       }
+
+       /* Set timer for closest deadline */
+       next = (__s32)(array->paa_deadline - cfs_time_current_sec() -
+                      at_early_margin);
+       if (next <= 0) {
+               ptlrpc_at_timer((unsigned long)svcpt);
+       } else {
+               cfs_timer_arm(&svcpt->scp_at_timer, cfs_time_shift(next));
+               CDEBUG(D_INFO, "armed %s at %+ds\n",
+                      svcpt->scp_service->srv_name, next);
+       }
+       cfs_spin_unlock(&svcpt->scp_at_lock);
 }
 
 /* Add rpc to early reply check list */
 static int ptlrpc_at_add_timed(struct ptlrpc_request *req)
 {
-        struct ptlrpc_service *svc = req->rq_rqbd->rqbd_service;
-        struct ptlrpc_request *rq;
+       struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
+       struct ptlrpc_at_array *array = &svcpt->scp_at_array;
+        struct ptlrpc_request *rq = NULL;
+        __u32 index;
         int found = 0;
 
         if (AT_OFF)
@@ -675,42 +1000,50 @@ static int ptlrpc_at_add_timed(struct ptlrpc_request *req)
         if ((lustre_msghdr_get_flags(req->rq_reqmsg) & MSGHDR_AT_SUPPORT) == 0)
                 return(-ENOSYS);
 
-        spin_lock(&svc->srv_at_lock);
-
-        if (unlikely(req->rq_sent_final)) {
-                spin_unlock(&svc->srv_at_lock);
-                return 0;
-        }
-
-        LASSERT(list_empty(&req->rq_timed_list));
-        /* Add to sorted list.  Presumably latest rpcs will have the latest
-           deadlines, so search backward. */
-        list_for_each_entry_reverse(rq, &svc->srv_at_list, rq_timed_list) {
-                if (req->rq_deadline >= rq->rq_deadline) {
-                        list_add(&req->rq_timed_list, &rq->rq_timed_list);
-                        found++;
-                        break;
+       cfs_spin_lock(&svcpt->scp_at_lock);
+        LASSERT(cfs_list_empty(&req->rq_timed_list));
+
+        index = (unsigned long)req->rq_deadline % array->paa_size;
+        if (array->paa_reqs_count[index] > 0) {
+                /* latest rpcs will have the latest deadlines in the list,
+                 * so search backward. */
+                cfs_list_for_each_entry_reverse(rq,
+                                                &array->paa_reqs_array[index],
+                                                rq_timed_list) {
+                        if (req->rq_deadline >= rq->rq_deadline) {
+                                cfs_list_add(&req->rq_timed_list,
+                                             &rq->rq_timed_list);
+                                break;
+                        }
                 }
         }
-        if (!found)
-                /* Add to front if shortest deadline or list empty */
-                list_add(&req->rq_timed_list, &svc->srv_at_list);
 
-        /* Check if we're the head of the list */
-        found = (svc->srv_at_list.next == &req->rq_timed_list);
+        /* Add the request at the head of the list */
+        if (cfs_list_empty(&req->rq_timed_list))
+                cfs_list_add(&req->rq_timed_list,
+                             &array->paa_reqs_array[index]);
 
-        spin_unlock(&svc->srv_at_lock);
+        cfs_spin_lock(&req->rq_lock);
+        req->rq_at_linked = 1;
+        cfs_spin_unlock(&req->rq_lock);
+        req->rq_at_index = index;
+        array->paa_reqs_count[index]++;
+        array->paa_count++;
+        if (array->paa_count == 1 || array->paa_deadline > req->rq_deadline) {
+                array->paa_deadline = req->rq_deadline;
+                found = 1;
+        }
+       cfs_spin_unlock(&svcpt->scp_at_lock);
 
-        if (found)
-                ptlrpc_at_set_timer(svc);
+       if (found)
+               ptlrpc_at_set_timer(svcpt);
 
-        return 0;
+       return 0;
 }
 
-static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req,
-                                      int extra_time)
+static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req)
 {
-        struct ptlrpc_service *svc = req->rq_rqbd->rqbd_service;
+       struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
         struct ptlrpc_request *reqcopy;
         struct lustre_msg *reqmsg;
         cfs_duration_t olddl = req->rq_deadline - cfs_time_current_sec();
@@ -723,8 +1056,8 @@ static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req,
         DEBUG_REQ(D_ADAPTTO, req,
                   "%ssending early reply (deadline %+lds, margin %+lds) for "
                   "%d+%d", AT_OFF ? "AT off - not " : "",
-                  olddl, olddl - at_get(&svc->srv_at_estimate),
-                  at_get(&svc->srv_at_estimate), extra_time);
+                 olddl, olddl - at_get(&svcpt->scp_at_estimate),
+                 at_get(&svcpt->scp_at_estimate), at_extra);
 
         if (AT_OFF)
                 RETURN(0);
@@ -744,36 +1077,42 @@ static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req,
                 RETURN(-ENOSYS);
         }
 
-        if (req->rq_export && req->rq_export->exp_in_recovery) {
-                /* don't increase server estimates during recovery, and give
-                   clients the full recovery time. */
-                newdl = cfs_time_current_sec() +
-                        req->rq_export->exp_obd->obd_recovery_timeout;
-        } else {
-                if (extra_time) {
-                        /* Fake our processing time into the future to ask the
-                           clients for some extra amount of time */
-                        extra_time += cfs_time_current_sec() -
-                                req->rq_arrival_time.tv_sec;
-                        at_add(&svc->srv_at_estimate, extra_time);
-                }
-                newdl = req->rq_arrival_time.tv_sec +
-                        at_get(&svc->srv_at_estimate);
-        }
-        if (req->rq_deadline >= newdl) {
-                /* We're not adding any time, no need to send an early reply
-                   (e.g. maybe at adaptive_max) */
-                DEBUG_REQ(D_WARNING, req, "Couldn't add any time ("
-                          CFS_DURATION_T"/"CFS_DURATION_T"), "
-                          "not sending early reply\n", olddl,
-                          cfs_time_sub(newdl, cfs_time_current_sec()));
-                RETURN(-ETIMEDOUT);
-        }
+        if (req->rq_export &&
+            lustre_msg_get_flags(req->rq_reqmsg) &
+            (MSG_REPLAY | MSG_REQ_REPLAY_DONE | MSG_LOCK_REPLAY_DONE)) {
+                /* During recovery, we don't want to send too many early
+                 * replies, but on the other hand we want to make sure the
+                 * client has enough time to resend if the rpc is lost. So
+                 * during the recovery period send at least 4 early replies,
+                 * spacing them every at_extra if we can. at_estimate should
+                 * always equal this fixed value during recovery. */
+               at_measured(&svcpt->scp_at_estimate, min(at_extra,
+                           req->rq_export->exp_obd->obd_recovery_timeout / 4));
+       } else {
+               /* Fake our processing time into the future to ask the clients
+                * for some extra amount of time */
+               at_measured(&svcpt->scp_at_estimate, at_extra +
+                           cfs_time_current_sec() -
+                           req->rq_arrival_time.tv_sec);
+
+               /* Check to see if we've actually increased the deadline -
+                * we may be past adaptive_max */
+               if (req->rq_deadline >= req->rq_arrival_time.tv_sec +
+                   at_get(&svcpt->scp_at_estimate)) {
+                       DEBUG_REQ(D_WARNING, req, "Couldn't add any time "
+                                 "(%ld/%ld), not sending early reply\n",
+                                 olddl, req->rq_arrival_time.tv_sec +
+                                 at_get(&svcpt->scp_at_estimate) -
+                                 cfs_time_current_sec());
+                       RETURN(-ETIMEDOUT);
+               }
+       }
+       newdl = cfs_time_current_sec() + at_get(&svcpt->scp_at_estimate);
 
         OBD_ALLOC(reqcopy, sizeof *reqcopy);
         if (reqcopy == NULL)
                 RETURN(-ENOMEM);
-        OBD_ALLOC(reqmsg, req->rq_reqlen);
+        OBD_ALLOC_LARGE(reqmsg, req->rq_reqlen);
         if (!reqmsg) {
                 OBD_FREE(reqcopy, sizeof *reqcopy);
                 RETURN(-ENOMEM);
@@ -790,10 +1129,12 @@ static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req,
         reqcopy->rq_reqmsg = reqmsg;
         memcpy(reqmsg, req->rq_reqmsg, req->rq_reqlen);
 
-        if (req->rq_sent_final) {
+        LASSERT(cfs_atomic_read(&req->rq_refcount));
+        /** if it is last refcount then early reply isn't needed */
+        if (cfs_atomic_read(&req->rq_refcount) == 1) {
                 DEBUG_REQ(D_ADAPTTO, reqcopy, "Normal reply already sent out, "
                           "abort sending early reply\n");
-                GOTO(out, rc = 0);
+                GOTO(out, rc = -EINVAL);
         }
 
         /* Connection ref */
@@ -831,62 +1172,91 @@ out_put:
         class_export_put(reqcopy->rq_export);
 out:
         sptlrpc_svc_ctx_decref(reqcopy);
-        OBD_FREE(reqmsg, req->rq_reqlen);
+        OBD_FREE_LARGE(reqmsg, req->rq_reqlen);
         OBD_FREE(reqcopy, sizeof *reqcopy);
         RETURN(rc);
 }
 
 /* Send early replies to everybody expiring within at_early_margin
    asking for at_extra time */
-static int ptlrpc_at_check_timed(struct ptlrpc_service *svc)
+static int ptlrpc_at_check_timed(struct ptlrpc_service_part *svcpt)
 {
+       struct ptlrpc_at_array *array = &svcpt->scp_at_array;
         struct ptlrpc_request *rq, *n;
-        struct list_head work_list;
+        cfs_list_t work_list;
+        __u32  index, count;
+        time_t deadline;
         time_t now = cfs_time_current_sec();
         cfs_duration_t delay;
         int first, counter = 0;
         ENTRY;
 
-        spin_lock(&svc->srv_at_lock);
-        if (svc->srv_at_check == 0) {
-                spin_unlock(&svc->srv_at_lock);
-                RETURN(0);
-        }
-        delay = cfs_time_sub(cfs_time_current(), svc->srv_at_checktime);
-        svc->srv_at_check = 0;
-
-        if (list_empty(&svc->srv_at_list)) {
-                spin_unlock(&svc->srv_at_lock);
-                RETURN(0);
-        }
-
-        /* The timer went off, but maybe the nearest rpc already completed. */
-        rq = list_entry(svc->srv_at_list.next, struct ptlrpc_request,
-                        rq_timed_list);
-        first = (int)(rq->rq_deadline - now);
-        if (first > at_early_margin) {
-                /* We've still got plenty of time.  Reset the timer. */
-                spin_unlock(&svc->srv_at_lock);
-                ptlrpc_at_set_timer(svc);
+       cfs_spin_lock(&svcpt->scp_at_lock);
+       if (svcpt->scp_at_check == 0) {
+               cfs_spin_unlock(&svcpt->scp_at_lock);
+               RETURN(0);
+       }
+       delay = cfs_time_sub(cfs_time_current(), svcpt->scp_at_checktime);
+       svcpt->scp_at_check = 0;
+
+       if (array->paa_count == 0) {
+               cfs_spin_unlock(&svcpt->scp_at_lock);
+               RETURN(0);
+       }
+
+       /* The timer went off, but maybe the nearest rpc already completed. */
+       first = array->paa_deadline - now;
+       if (first > at_early_margin) {
+               /* We've still got plenty of time.  Reset the timer. */
+               cfs_spin_unlock(&svcpt->scp_at_lock);
+               ptlrpc_at_set_timer(svcpt);
                 RETURN(0);
         }
 
         /* We're close to a timeout, and we don't know how much longer the
            server will take. Send early replies to everyone expiring soon. */
         CFS_INIT_LIST_HEAD(&work_list);
-        list_for_each_entry_safe(rq, n, &svc->srv_at_list, rq_timed_list) {
-                if (rq->rq_deadline <= now + at_early_margin) {
-                        list_move_tail(&rq->rq_timed_list, &work_list);
-                        counter++;
-                } else {
+        deadline = -1;
+        index = (unsigned long)array->paa_deadline % array->paa_size;
+        count = array->paa_count;
+        while (count > 0) {
+                count -= array->paa_reqs_count[index];
+                cfs_list_for_each_entry_safe(rq, n,
+                                             &array->paa_reqs_array[index],
+                                             rq_timed_list) {
+                        if (rq->rq_deadline <= now + at_early_margin) {
+                                cfs_list_del_init(&rq->rq_timed_list);
+                                /**
+                                 * ptlrpc_server_drop_request() may drop
+                                 * refcount to 0 already. Let's check this and
+                                 * don't add entry to work_list
+                                 */
+                                if (likely(cfs_atomic_inc_not_zero(&rq->rq_refcount)))
+                                        cfs_list_add(&rq->rq_timed_list, &work_list);
+                                counter++;
+                                array->paa_reqs_count[index]--;
+                                array->paa_count--;
+                                cfs_spin_lock(&rq->rq_lock);
+                                rq->rq_at_linked = 0;
+                                cfs_spin_unlock(&rq->rq_lock);
+                                continue;
+                        }
+
+                        /* update the earliest deadline */
+                        if (deadline == -1 || rq->rq_deadline < deadline)
+                                deadline = rq->rq_deadline;
+
                         break;
                 }
-        }
 
-        spin_unlock(&svc->srv_at_lock);
+                if (++index >= array->paa_size)
+                        index = 0;
+        }
+        array->paa_deadline = deadline;
+       cfs_spin_unlock(&svcpt->scp_at_lock);
 
-        /* we have a new earliest deadline, restart the timer */
-        ptlrpc_at_set_timer(svc);
+       /* we have a new earliest deadline, restart the timer */
+       ptlrpc_at_set_timer(svcpt);
 
         CDEBUG(D_ADAPTTO, "timeout in %+ds, asking for %d secs on %d early "
                "replies\n", first, at_extra, counter);
@@ -894,60 +1264,292 @@ static int ptlrpc_at_check_timed(struct ptlrpc_service *svc)
                 /* We're already past request deadlines before we even get a
                    chance to send early replies */
                 LCONSOLE_WARN("%s: This server is not able to keep up with "
-                              "request traffic (cpu-bound).\n", svc->srv_name);
-                CWARN("earlyQ=%d reqQ=%d recA=%d, svcEst=%d, "
-                      "delay="CFS_DURATION_T"(jiff)\n",
-                      counter, svc->srv_n_queued_reqs, svc->srv_n_active_reqs,
-                      at_get(&svc->srv_at_estimate), delay);
-        }
-
-        /* ptlrpc_server_finish_request may delete an entry out of
-         * the work list */
-        spin_lock(&svc->srv_at_lock);
-        while (!list_empty(&work_list)) {
-                rq = list_entry(work_list.next, struct ptlrpc_request,
-                                rq_timed_list);
-                list_del_init(&rq->rq_timed_list);
-                /* if the entry is still in the worklist, it hasn't been
-                   deleted, and is safe to take a ref to keep the req around */
-                atomic_inc(&rq->rq_refcount);
-                spin_unlock(&svc->srv_at_lock);
-
-                if (ptlrpc_at_send_early_reply(rq, at_extra) == 0)
+                             "request traffic (cpu-bound).\n",
+                             svcpt->scp_service->srv_name);
+               CWARN("earlyQ=%d reqQ=%d recA=%d, svcEst=%d, "
+                     "delay="CFS_DURATION_T"(jiff)\n",
+                     counter, svcpt->scp_nreqs_incoming,
+                     svcpt->scp_nreqs_active,
+                     at_get(&svcpt->scp_at_estimate), delay);
+        }
+
+        /* we took additional refcount so entries can't be deleted from list, no
+         * locking is needed */
+        while (!cfs_list_empty(&work_list)) {
+                rq = cfs_list_entry(work_list.next, struct ptlrpc_request,
+                                    rq_timed_list);
+                cfs_list_del_init(&rq->rq_timed_list);
+
+                if (ptlrpc_at_send_early_reply(rq) == 0)
                         ptlrpc_at_add_timed(rq);
 
                 ptlrpc_server_drop_request(rq);
-                spin_lock(&svc->srv_at_lock);
         }
-        spin_unlock(&svc->srv_at_lock);
 
-        RETURN(0);
+       RETURN(1); /* return "did_something" for liblustre */
 }
 
-/* Handle freshly incoming reqs, add to timed early reply list,
-   pass on to regular request queue */
-static int
-ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
+/**
+ * Put the request to the export list if the request may become
+ * a high priority one.
+ */
+static int ptlrpc_hpreq_init(struct ptlrpc_service *svc,
+                             struct ptlrpc_request *req)
 {
-        struct ptlrpc_request *req;
-        __u32                  deadline;
-        int                    rc;
+        int rc = 0;
         ENTRY;
 
-        LASSERT(svc);
+       if (svc->srv_ops.so_hpreq_handler) {
+               rc = svc->srv_ops.so_hpreq_handler(req);
+                if (rc)
+                        RETURN(rc);
+        }
+        if (req->rq_export && req->rq_ops) {
+                /* Perform request specific check. We should do this check
+                 * before the request is added into exp_hp_rpcs list otherwise
+                 * it may hit swab race at LU-1044. */
+                if (req->rq_ops->hpreq_check)
+                        rc = req->rq_ops->hpreq_check(req);
 
-        spin_lock(&svc->srv_lock);
-        if (list_empty(&svc->srv_req_in_queue)) {
-                spin_unlock(&svc->srv_lock);
-                RETURN(0);
+                cfs_spin_lock_bh(&req->rq_export->exp_rpc_lock);
+                cfs_list_add(&req->rq_exp_list,
+                             &req->rq_export->exp_hp_rpcs);
+                cfs_spin_unlock_bh(&req->rq_export->exp_rpc_lock);
         }
 
-        req = list_entry(svc->srv_req_in_queue.next,
-                         struct ptlrpc_request, rq_list);
-        list_del_init (&req->rq_list);
-        /* Consider this still a "queued" request as far as stats are
-           concerned */
-        spin_unlock(&svc->srv_lock);
+        RETURN(rc);
+}
+
+/** Remove the request from the export list. */
+static void ptlrpc_hpreq_fini(struct ptlrpc_request *req)
+{
+        ENTRY;
+        if (req->rq_export && req->rq_ops) {
+                /* refresh lock timeout again so that client has more
+                 * room to send lock cancel RPC. */
+                if (req->rq_ops->hpreq_fini)
+                        req->rq_ops->hpreq_fini(req);
+
+                cfs_spin_lock_bh(&req->rq_export->exp_rpc_lock);
+                cfs_list_del_init(&req->rq_exp_list);
+                cfs_spin_unlock_bh(&req->rq_export->exp_rpc_lock);
+        }
+        EXIT;
+}
+
+/**
+ * Make the request a high priority one.
+ *
+ * All the high priority requests are queued in a separate FIFO
+ * ptlrpc_service_part::scp_hpreq_pending list which is parallel to
+ * ptlrpc_service_part::scp_req_pending list but has a higher priority
+ * for handling.
+ *
+ * \see ptlrpc_server_handle_request().
+ */
+static void ptlrpc_hpreq_reorder_nolock(struct ptlrpc_service_part *svcpt,
+                                        struct ptlrpc_request *req)
+{
+        ENTRY;
+
+        cfs_spin_lock(&req->rq_lock);
+        if (req->rq_hp == 0) {
+                int opc = lustre_msg_get_opc(req->rq_reqmsg);
+
+                /* Add to the high priority queue. */
+               cfs_list_move_tail(&req->rq_list, &svcpt->scp_hreq_pending);
+                req->rq_hp = 1;
+                if (opc != OBD_PING)
+                        DEBUG_REQ(D_RPCTRACE, req, "high priority req");
+        }
+        cfs_spin_unlock(&req->rq_lock);
+        EXIT;
+}
+
+/**
+ * \see ptlrpc_hpreq_reorder_nolock
+ */
+void ptlrpc_hpreq_reorder(struct ptlrpc_request *req)
+{
+       struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
+       ENTRY;
+
+       cfs_spin_lock(&svcpt->scp_req_lock);
+       /* It may happen that the request is already taken for the processing
+        * but still in the export list, or the request is not in the request
+        * queue but in the export list already, do not add it into the
+        * HP list. */
+       if (!cfs_list_empty(&req->rq_list))
+               ptlrpc_hpreq_reorder_nolock(svcpt, req);
+       cfs_spin_unlock(&svcpt->scp_req_lock);
+       EXIT;
+}
+
+/** Check if the request is a high priority one. */
+static int ptlrpc_server_hpreq_check(struct ptlrpc_service *svc,
+                                     struct ptlrpc_request *req)
+{
+        ENTRY;
+
+        /* Check by request opc. */
+        if (OBD_PING == lustre_msg_get_opc(req->rq_reqmsg))
+                RETURN(1);
+
+        RETURN(ptlrpc_hpreq_init(svc, req));
+}
+
+/** Check if a request is a high priority one. */
+static int ptlrpc_server_request_add(struct ptlrpc_service_part *svcpt,
+                                    struct ptlrpc_request *req)
+{
+       int     rc;
+       ENTRY;
+
+       rc = ptlrpc_server_hpreq_check(svcpt->scp_service, req);
+       if (rc < 0)
+               RETURN(rc);
+
+       cfs_spin_lock(&svcpt->scp_req_lock);
+
+       if (rc)
+               ptlrpc_hpreq_reorder_nolock(svcpt, req);
+       else
+               cfs_list_add_tail(&req->rq_list, &svcpt->scp_req_pending);
+
+       cfs_spin_unlock(&svcpt->scp_req_lock);
+
+       RETURN(0);
+}
+
+/**
+ * Allow to handle high priority request
+ * User can call it w/o any lock but need to hold
+ * ptlrpc_service_part::scp_req_lock to get reliable result
+ */
+static int ptlrpc_server_allow_high(struct ptlrpc_service_part *svcpt,
+                                   int force)
+{
+       if (force)
+               return 1;
+
+       if (svcpt->scp_nreqs_active >= svcpt->scp_nthrs_running - 1)
+               return 0;
+
+       return cfs_list_empty(&svcpt->scp_req_pending) ||
+              svcpt->scp_hreq_count < svcpt->scp_service->srv_hpreq_ratio;
+}
+
+static int ptlrpc_server_high_pending(struct ptlrpc_service_part *svcpt,
+                                     int force)
+{
+       return ptlrpc_server_allow_high(svcpt, force) &&
+              !cfs_list_empty(&svcpt->scp_hreq_pending);
+}
+
+/**
+ * Only allow normal priority requests on a service that has a high-priority
+ * queue if forced (i.e. cleanup), if there are other high priority requests
+ * already being processed (i.e. those threads can service more high-priority
+ * requests), or if there are enough idle threads that a later thread can do
+ * a high priority request.
+ * User can call it w/o any lock but need to hold
+ * ptlrpc_service_part::scp_req_lock to get reliable result
+ */
+static int ptlrpc_server_allow_normal(struct ptlrpc_service_part *svcpt,
+                                     int force)
+{
+#ifndef __KERNEL__
+       if (1) /* always allow to handle normal request for liblustre */
+               return 1;
+#endif
+       if (force ||
+           svcpt->scp_nreqs_active < svcpt->scp_nthrs_running - 2)
+               return 1;
+
+       if (svcpt->scp_nreqs_active >= svcpt->scp_nthrs_running - 1)
+               return 0;
+
+       return svcpt->scp_nhreqs_active > 0 ||
+              svcpt->scp_service->srv_ops.so_hpreq_handler == NULL;
+}
+
+static int ptlrpc_server_normal_pending(struct ptlrpc_service_part *svcpt,
+                                       int force)
+{
+       return ptlrpc_server_allow_normal(svcpt, force) &&
+              !cfs_list_empty(&svcpt->scp_req_pending);
+}
+
+/**
+ * Returns true if there are requests available in incoming
+ * request queue for processing and it is allowed to fetch them.
+ * User can call it w/o any lock but need to hold ptlrpc_service::scp_req_lock
+ * to get reliable result
+ * \see ptlrpc_server_allow_normal
+ * \see ptlrpc_server_allow high
+ */
+static inline int
+ptlrpc_server_request_pending(struct ptlrpc_service_part *svcpt, int force)
+{
+       return ptlrpc_server_high_pending(svcpt, force) ||
+              ptlrpc_server_normal_pending(svcpt, force);
+}
+
+/**
+ * Fetch a request for processing from queue of unprocessed requests.
+ * Favors high-priority requests.
+ * Returns a pointer to fetched request.
+ */
+static struct ptlrpc_request *
+ptlrpc_server_request_get(struct ptlrpc_service_part *svcpt, int force)
+{
+       struct ptlrpc_request *req;
+       ENTRY;
+
+       if (ptlrpc_server_high_pending(svcpt, force)) {
+               req = cfs_list_entry(svcpt->scp_hreq_pending.next,
+                                    struct ptlrpc_request, rq_list);
+               svcpt->scp_hreq_count++;
+               RETURN(req);
+       }
+
+       if (ptlrpc_server_normal_pending(svcpt, force)) {
+               req = cfs_list_entry(svcpt->scp_req_pending.next,
+                                    struct ptlrpc_request, rq_list);
+               svcpt->scp_hreq_count = 0;
+               RETURN(req);
+       }
+       RETURN(NULL);
+}
+
+/**
+ * Handle freshly incoming reqs, add to timed early reply list,
+ * pass on to regular request queue.
+ * All incoming requests pass through here before getting into
+ * ptlrpc_server_handle_req later on.
+ */
+static int
+ptlrpc_server_handle_req_in(struct ptlrpc_service_part *svcpt)
+{
+       struct ptlrpc_service   *svc = svcpt->scp_service;
+       struct ptlrpc_request   *req;
+       __u32                   deadline;
+       int                     rc;
+       ENTRY;
+
+       cfs_spin_lock(&svcpt->scp_lock);
+       if (cfs_list_empty(&svcpt->scp_req_incoming)) {
+               cfs_spin_unlock(&svcpt->scp_lock);
+               RETURN(0);
+       }
+
+       req = cfs_list_entry(svcpt->scp_req_incoming.next,
+                            struct ptlrpc_request, rq_list);
+       cfs_list_del_init(&req->rq_list);
+       svcpt->scp_nreqs_incoming--;
+       /* Consider this still a "queued" request as far as stats are
+        * concerned */
+       cfs_spin_unlock(&svcpt->scp_lock);
 
         /* go through security check/transform */
         rc = sptlrpc_svc_unwrap_request(req);
@@ -963,15 +1565,18 @@ ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
                 LBUG();
         }
 
-        /* Clear request swab mask; this is a new request */
-        req->rq_req_swab_mask = 0;
-
-        rc = lustre_unpack_msg(req->rq_reqmsg, req->rq_reqlen);
-        if (rc != 0) {
-                CERROR("error unpacking request: ptl %d from %s x"LPU64"\n",
-                       svc->srv_req_portal, libcfs_id2str(req->rq_peer),
-                       req->rq_xid);
-                goto err_req;
+        /*
+         * for null-flavored rpc, msg has been unpacked by sptlrpc, although
+         * redo it wouldn't be harmful.
+         */
+        if (SPTLRPC_FLVR_POLICY(req->rq_flvr.sf_rpc) != SPTLRPC_POLICY_NULL) {
+                rc = ptlrpc_unpack_req_msg(req, req->rq_reqlen);
+                if (rc != 0) {
+                        CERROR("error unpacking request: ptl %d from %s "
+                               "x"LPU64"\n", svc->srv_req_portal,
+                               libcfs_id2str(req->rq_peer), req->rq_xid);
+                        goto err_req;
+                }
         }
 
         rc = lustre_unpack_req_ptlrpc_body(req, MSG_PTLRPC_BODY_OFF);
@@ -982,6 +1587,13 @@ ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
                 goto err_req;
         }
 
+        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DROP_REQ_OPC) &&
+            lustre_msg_get_opc(req->rq_reqmsg) == cfs_fail_val) {
+                CERROR("drop incoming rpc opc %u, x"LPU64"\n",
+                       cfs_fail_val, req->rq_xid);
+                goto err_req;
+        }
+
         rc = -EINVAL;
         if (lustre_msg_get_type(req->rq_reqmsg) != PTL_RPC_MSG_REQUEST) {
                 CERROR("wrong packet type received (type=%u) from %s\n",
@@ -990,7 +1602,19 @@ ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
                 goto err_req;
         }
 
-        CDEBUG(D_NET, "got req "LPD64"\n", req->rq_xid);
+        switch(lustre_msg_get_opc(req->rq_reqmsg)) {
+        case MDS_WRITEPAGE:
+        case OST_WRITE:
+                req->rq_bulk_write = 1;
+                break;
+        case MDS_READPAGE:
+        case OST_READ:
+        case MGS_CONFIG_READ:
+                req->rq_bulk_read = 1;
+                break;
+        }
+
+        CDEBUG(D_RPCTRACE, "got req x"LPU64"\n", req->rq_xid);
 
         req->rq_export = class_conn2export(
                 lustre_msg_get_handle(req->rq_reqmsg));
@@ -1003,10 +1627,9 @@ ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
                                           "illegal security flavor,");
                 }
 
-                class_export_put(req->rq_export);
-                req->rq_export = NULL;
                 if (rc)
                         goto err_req;
+                ptlrpc_update_export_timer(req->rq_export, 0);
         }
 
         /* req_in handling should/must be fast */
@@ -1029,82 +1652,108 @@ ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
         ptlrpc_at_add_timed(req);
 
         /* Move it over to the request processing queue */
-        spin_lock(&svc->srv_lock);
-        list_add_tail(&req->rq_list, &svc->srv_request_queue);
-        cfs_waitq_signal(&svc->srv_waitq);
-        spin_unlock(&svc->srv_lock);
-        RETURN(1);
+       rc = ptlrpc_server_request_add(svcpt, req);
+       if (rc) {
+               ptlrpc_hpreq_fini(req);
+               GOTO(err_req, rc);
+       }
+       cfs_waitq_signal(&svcpt->scp_waitq);
+       RETURN(1);
 
 err_req:
-        spin_lock(&svc->srv_lock);
-        svc->srv_n_queued_reqs--;
-        svc->srv_n_active_reqs++;
-        spin_unlock(&svc->srv_lock);
-        ptlrpc_server_finish_request(req);
+       cfs_spin_lock(&svcpt->scp_req_lock);
+       svcpt->scp_nreqs_active++;
+       cfs_spin_unlock(&svcpt->scp_req_lock);
+       ptlrpc_server_finish_request(svcpt, req);
 
-        RETURN(1);
+       RETURN(1);
 }
 
+/**
+ * Main incoming request handling logic.
+ * Calls handler function from service to do actual processing.
+ */
 static int
-ptlrpc_server_handle_request(struct ptlrpc_service *svc,
-                             struct ptlrpc_thread *thread)
+ptlrpc_server_handle_request(struct ptlrpc_service_part *svcpt,
+                            struct ptlrpc_thread *thread)
 {
+       struct ptlrpc_service *svc = svcpt->scp_service;
         struct obd_export     *export = NULL;
         struct ptlrpc_request *request;
         struct timeval         work_start;
         struct timeval         work_end;
         long                   timediff;
         int                    rc;
+        int                    fail_opc = 0;
         ENTRY;
 
-        LASSERT(svc);
-
-        spin_lock(&svc->srv_lock);
-        if (unlikely(list_empty (&svc->srv_request_queue) ||
-            (
+       cfs_spin_lock(&svcpt->scp_req_lock);
 #ifndef __KERNEL__
-             /* !@%$# liblustre only has 1 thread */
-             svc->srv_n_difficult_replies != 0 &&
+       /* !@%$# liblustre only has 1 thread */
+       if (cfs_atomic_read(&svcpt->scp_nreps_difficult) != 0) {
+               cfs_spin_unlock(&svcpt->scp_req_lock);
+               RETURN(0);
+       }
 #endif
-             svc->srv_n_active_reqs >= (svc->srv_threads_running - 1)))) {
-                 /* Don't handle regular requests in the last thread, in order               * re
-                  * to handle difficult replies (which might block other threads)
-                  * as well as handle any incoming reqs, early replies, etc.
-                  * That means we always need at least 2 service threads. */
-                spin_unlock(&svc->srv_lock);
+       request = ptlrpc_server_request_get(svcpt, 0);
+       if  (request == NULL) {
+               cfs_spin_unlock(&svcpt->scp_req_lock);
                 RETURN(0);
         }
 
-        request = list_entry (svc->srv_request_queue.next,
-                              struct ptlrpc_request, rq_list);
-        list_del_init (&request->rq_list);
-        svc->srv_n_queued_reqs--;
-        svc->srv_n_active_reqs++;
+        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT))
+                fail_opc = OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT;
+        else if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_TIMEOUT))
+                fail_opc = OBD_FAIL_PTLRPC_HPREQ_TIMEOUT;
+
+        if (unlikely(fail_opc)) {
+                if (request->rq_export && request->rq_ops) {
+                       cfs_spin_unlock(&svcpt->scp_req_lock);
+
+                       OBD_FAIL_TIMEOUT(fail_opc, 4);
+
+                       cfs_spin_lock(&svcpt->scp_req_lock);
+                       request = ptlrpc_server_request_get(svcpt, 0);
+                       if  (request == NULL) {
+                               cfs_spin_unlock(&svcpt->scp_req_lock);
+                               RETURN(0);
+                       }
+               }
+       }
+
+       cfs_list_del_init(&request->rq_list);
+       svcpt->scp_nreqs_active++;
+       if (request->rq_hp)
+               svcpt->scp_nhreqs_active++;
 
-        spin_unlock(&svc->srv_lock);
+       cfs_spin_unlock(&svcpt->scp_req_lock);
+
+        ptlrpc_rqphase_move(request, RQ_PHASE_INTERPRET);
 
         if(OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DUMP_LOG))
                 libcfs_debug_dumplog();
 
-        do_gettimeofday(&work_start);
+        cfs_gettimeofday(&work_start);
         timediff = cfs_timeval_sub(&work_start, &request->rq_arrival_time,NULL);
         if (likely(svc->srv_stats != NULL)) {
                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQWAIT_CNTR,
                                     timediff);
                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQQDEPTH_CNTR,
-                                    svc->srv_n_queued_reqs);
-                lprocfs_counter_add(svc->srv_stats, PTLRPC_REQACTIVE_CNTR,
-                                    svc->srv_n_active_reqs);
-                lprocfs_counter_add(svc->srv_stats, PTLRPC_TIMEOUT,
-                                    at_get(&svc->srv_at_estimate));
+                                   svcpt->scp_nreqs_incoming);
+               lprocfs_counter_add(svc->srv_stats, PTLRPC_REQACTIVE_CNTR,
+                                   svcpt->scp_nreqs_active);
+               lprocfs_counter_add(svc->srv_stats, PTLRPC_TIMEOUT,
+                                   at_get(&svcpt->scp_at_estimate));
         }
 
-        rc = lu_context_init(&request->rq_session, LCT_SESSION);
+        rc = lu_context_init(&request->rq_session,
+                             LCT_SESSION|LCT_REMEMBER|LCT_NOREF);
         if (rc) {
                 CERROR("Failure to initialize session: %d\n", rc);
                 goto out_req;
         }
         request->rq_session.lc_thread = thread;
+        request->rq_session.lc_cookie = 0x5;
         lu_context_enter(&request->rq_session);
 
         CDEBUG(D_NET, "got req "LPU64"\n", request->rq_xid);
@@ -1113,9 +1762,6 @@ ptlrpc_server_handle_request(struct ptlrpc_service *svc,
         if (thread)
                 request->rq_svc_thread->t_env->le_ses = &request->rq_session;
 
-        request->rq_export = class_conn2export(
-                                     lustre_msg_get_handle(request->rq_reqmsg));
-
         if (likely(request->rq_export)) {
                 if (unlikely(ptlrpc_check_req(request)))
                         goto put_conn;
@@ -1136,41 +1782,27 @@ ptlrpc_server_handle_request(struct ptlrpc_service *svc,
                 goto put_rpc_export;
         }
 
-        request->rq_phase = RQ_PHASE_INTERPRET;
-
         CDEBUG(D_RPCTRACE, "Handling RPC pname:cluuid+ref:pid:xid:nid:opc "
                "%s:%s+%d:%d:x"LPU64":%s:%d\n", cfs_curproc_comm(),
                (request->rq_export ?
                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
                (request->rq_export ?
-                atomic_read(&request->rq_export->exp_refcount) : -99),
+                cfs_atomic_read(&request->rq_export->exp_refcount) : -99),
                lustre_msg_get_status(request->rq_reqmsg), request->rq_xid,
                libcfs_id2str(request->rq_peer),
                lustre_msg_get_opc(request->rq_reqmsg));
 
-        OBD_FAIL_TIMEOUT_MS(OBD_FAIL_PTLRPC_PAUSE_REQ, obd_fail_val);
-
-        rc = svc->srv_handler(request);
+        if (lustre_msg_get_opc(request->rq_reqmsg) != OBD_PING)
+                CFS_FAIL_TIMEOUT_MS(OBD_FAIL_PTLRPC_PAUSE_REQ, cfs_fail_val);
 
-        request->rq_phase = RQ_PHASE_COMPLETE;
+       rc = svc->srv_ops.so_req_handler(request);
 
-        CDEBUG(D_RPCTRACE, "Handled RPC pname:cluuid+ref:pid:xid:nid:opc "
-               "%s:%s+%d:%d:x"LPU64":%s:%d\n", cfs_curproc_comm(),
-               (request->rq_export ?
-                (char *)request->rq_export->exp_client_uuid.uuid : "0"),
-               (request->rq_export ?
-                atomic_read(&request->rq_export->exp_refcount) : -99),
-               lustre_msg_get_status(request->rq_reqmsg), request->rq_xid,
-               libcfs_id2str(request->rq_peer),
-               lustre_msg_get_opc(request->rq_reqmsg));
+        ptlrpc_rqphase_move(request, RQ_PHASE_COMPLETE);
 
 put_rpc_export:
         if (export != NULL)
                 class_export_rpc_put(export);
 put_conn:
-        if (likely(request->rq_export != NULL))
-                class_export_put(request->rq_export);
-
         lu_context_exit(&request->rq_session);
         lu_context_fini(&request->rq_session);
 
@@ -1184,17 +1816,28 @@ put_conn:
                           request->rq_deadline));
         }
 
-        do_gettimeofday(&work_end);
+        cfs_gettimeofday(&work_end);
         timediff = cfs_timeval_sub(&work_end, &work_start, NULL);
-        CDEBUG(D_RPCTRACE, "request x"LPU64" opc %u from %s processed in "
+        CDEBUG(D_RPCTRACE, "Handled RPC pname:cluuid+ref:pid:xid:nid:opc "
+               "%s:%s+%d:%d:x"LPU64":%s:%d Request procesed in "
                "%ldus (%ldus total) trans "LPU64" rc %d/%d\n",
-               request->rq_xid, lustre_msg_get_opc(request->rq_reqmsg),
-               libcfs_id2str(request->rq_peer), timediff,
-               cfs_timeval_sub(&work_end, &request->rq_arrival_time, NULL),
-               request->rq_repmsg ? lustre_msg_get_transno(request->rq_repmsg) :
-               request->rq_transno, request->rq_status,
-               request->rq_repmsg ? lustre_msg_get_status(request->rq_repmsg):
-               -999);
+                cfs_curproc_comm(),
+                (request->rq_export ?
+                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
+                (request->rq_export ?
+                 cfs_atomic_read(&request->rq_export->exp_refcount) : -99),
+                lustre_msg_get_status(request->rq_reqmsg),
+                request->rq_xid,
+                libcfs_id2str(request->rq_peer),
+                lustre_msg_get_opc(request->rq_reqmsg),
+                timediff,
+                cfs_timeval_sub(&work_end, &request->rq_arrival_time, NULL),
+                (request->rq_repmsg ?
+                 lustre_msg_get_transno(request->rq_repmsg) :
+                 request->rq_transno),
+                request->rq_status,
+                (request->rq_repmsg ?
+                 lustre_msg_get_status(request->rq_repmsg) : -999));
         if (likely(svc->srv_stats != NULL && request->rq_reqmsg != NULL)) {
                 __u32 op = lustre_msg_get_opc(request->rq_reqmsg);
                 int opc = opcode_offset(op);
@@ -1215,52 +1858,64 @@ put_conn:
         }
 
 out_req:
-        ptlrpc_server_finish_request(request);
+       ptlrpc_server_finish_request(svcpt, request);
 
-        RETURN(1);
+       RETURN(1);
 }
 
+/**
+ * An internal function to process a single reply state object.
+ */
 static int
-ptlrpc_server_handle_reply (struct ptlrpc_service *svc)
+ptlrpc_handle_rs(struct ptlrpc_reply_state *rs)
 {
-        struct ptlrpc_reply_state *rs;
+       struct ptlrpc_service_part *svcpt = rs->rs_svcpt;
+       struct ptlrpc_service     *svc = svcpt->scp_service;
         struct obd_export         *exp;
-        struct obd_device         *obd;
         int                        nlocks;
         int                        been_handled;
         ENTRY;
 
-        spin_lock(&svc->srv_lock);
-        if (list_empty (&svc->srv_reply_queue)) {
-                spin_unlock(&svc->srv_lock);
-                RETURN(0);
-        }
-
-        rs = list_entry (svc->srv_reply_queue.next,
-                         struct ptlrpc_reply_state, rs_list);
-
         exp = rs->rs_export;
-        obd = exp->exp_obd;
 
         LASSERT (rs->rs_difficult);
         LASSERT (rs->rs_scheduled);
+        LASSERT (cfs_list_empty(&rs->rs_list));
 
-        list_del_init (&rs->rs_list);
-
-        /* Disengage from notifiers carefully (lock order - irqrestore below!)*/
-        spin_unlock(&svc->srv_lock);
-
-        spin_lock (&obd->obd_uncommitted_replies_lock);
-        /* Noop if removed already */
-        list_del_init (&rs->rs_obd_list);
-        spin_unlock (&obd->obd_uncommitted_replies_lock);
-
-        spin_lock (&exp->exp_lock);
+        cfs_spin_lock (&exp->exp_lock);
         /* Noop if removed already */
-        list_del_init (&rs->rs_exp_list);
-        spin_unlock (&exp->exp_lock);
+        cfs_list_del_init (&rs->rs_exp_list);
+        cfs_spin_unlock (&exp->exp_lock);
+
+        /* The disk commit callback holds exp_uncommitted_replies_lock while it
+         * iterates over newly committed replies, removing them from
+         * exp_uncommitted_replies.  It then drops this lock and schedules the
+         * replies it found for handling here.
+         *
+         * We can avoid contention for exp_uncommitted_replies_lock between the
+         * HRT threads and further commit callbacks by checking rs_committed
+         * which is set in the commit callback while it holds both
+         * rs_lock and exp_uncommitted_reples.
+         *
+         * If we see rs_committed clear, the commit callback _may_ not have
+         * handled this reply yet and we race with it to grab
+         * exp_uncommitted_replies_lock before removing the reply from
+         * exp_uncommitted_replies.  Note that if we lose the race and the
+         * reply has already been removed, list_del_init() is a noop.
+         *
+         * If we see rs_committed set, we know the commit callback is handling,
+         * or has handled this reply since store reordering might allow us to
+         * see rs_committed set out of sequence.  But since this is done
+         * holding rs_lock, we can be sure it has all completed once we hold
+         * rs_lock, which we do right next.
+         */
+        if (!rs->rs_committed) {
+                cfs_spin_lock(&exp->exp_uncommitted_replies_lock);
+                cfs_list_del_init(&rs->rs_obd_list);
+                cfs_spin_unlock(&exp->exp_uncommitted_replies_lock);
+        }
 
-        spin_lock(&svc->srv_lock);
+        cfs_spin_lock(&rs->rs_lock);
 
         been_handled = rs->rs_handled;
         rs->rs_handled = 1;
@@ -1274,13 +1929,12 @@ ptlrpc_server_handle_reply (struct ptlrpc_service *svc)
                 CWARN("All locks stolen from rs %p x"LPD64".t"LPD64
                       " o%d NID %s\n",
                       rs,
-                      rs->rs_xid, rs->rs_transno,
-                      lustre_msg_get_opc(rs->rs_msg),
+                      rs->rs_xid, rs->rs_transno, rs->rs_opc,
                       libcfs_nid2str(exp->exp_connection->c_peer.nid));
         }
 
         if ((!been_handled && rs->rs_on_net) || nlocks > 0) {
-                spin_unlock(&svc->srv_lock);
+                cfs_spin_unlock(&rs->rs_lock);
 
                 if (!been_handled && rs->rs_on_net) {
                         LNetMDUnlink(rs->rs_md_h);
@@ -1292,95 +1946,110 @@ ptlrpc_server_handle_reply (struct ptlrpc_service *svc)
                         ldlm_lock_decref(&rs->rs_locks[nlocks],
                                          rs->rs_modes[nlocks]);
 
-                spin_lock(&svc->srv_lock);
+                cfs_spin_lock(&rs->rs_lock);
         }
 
         rs->rs_scheduled = 0;
 
         if (!rs->rs_on_net) {
                 /* Off the net */
-                svc->srv_n_difficult_replies--;
-                if (svc->srv_n_difficult_replies == 0 && svc->srv_is_stopping)
-                        /* wake up threads that are being stopped by
-                           ptlrpc_unregister_service/ptlrpc_stop_threads
-                           and sleep waiting svr_n_difficult_replies == 0 */
-                        cfs_waitq_broadcast(&svc->srv_waitq);
-                spin_unlock(&svc->srv_lock);
+                cfs_spin_unlock(&rs->rs_lock);
 
                 class_export_put (exp);
                 rs->rs_export = NULL;
                 ptlrpc_rs_decref (rs);
-                atomic_dec (&svc->srv_outstanding_replies);
-                RETURN(1);
-        }
-
-        /* still on the net; callback will schedule */
-        spin_unlock(&svc->srv_lock);
-        RETURN(1);
+               if (cfs_atomic_dec_and_test(&svcpt->scp_nreps_difficult) &&
+                   svc->srv_is_stopping)
+                       cfs_waitq_broadcast(&svcpt->scp_waitq);
+               RETURN(1);
+       }
+
+       /* still on the net; callback will schedule */
+       cfs_spin_unlock(&rs->rs_lock);
+       RETURN(1);
 }
 
 #ifndef __KERNEL__
+
+/**
+ * Check whether given service has a reply available for processing
+ * and process it.
+ *
+ * \param svc a ptlrpc service
+ * \retval 0 no replies processed
+ * \retval 1 one reply processed
+ */
+static int
+ptlrpc_server_handle_reply(struct ptlrpc_service_part *svcpt)
+{
+       struct ptlrpc_reply_state *rs = NULL;
+       ENTRY;
+
+       cfs_spin_lock(&svcpt->scp_rep_lock);
+       if (!cfs_list_empty(&svcpt->scp_rep_queue)) {
+               rs = cfs_list_entry(svcpt->scp_rep_queue.prev,
+                                   struct ptlrpc_reply_state,
+                                   rs_list);
+               cfs_list_del_init(&rs->rs_list);
+       }
+       cfs_spin_unlock(&svcpt->scp_rep_lock);
+       if (rs != NULL)
+               ptlrpc_handle_rs(rs);
+       RETURN(rs != NULL);
+}
+
 /* FIXME make use of timeout later */
 int
 liblustre_check_services (void *arg)
 {
         int  did_something = 0;
         int  rc;
-        struct list_head *tmp, *nxt;
+        cfs_list_t *tmp, *nxt;
         ENTRY;
 
         /* I'm relying on being single threaded, not to have to lock
          * ptlrpc_all_services etc */
-        list_for_each_safe (tmp, nxt, &ptlrpc_all_services) {
+        cfs_list_for_each_safe (tmp, nxt, &ptlrpc_all_services) {
                 struct ptlrpc_service *svc =
-                        list_entry (tmp, struct ptlrpc_service, srv_list);
+                        cfs_list_entry (tmp, struct ptlrpc_service, srv_list);
+               struct ptlrpc_service_part *svcpt;
 
-                if (svc->srv_threads_running != 0)     /* I've recursed */
-                        continue;
+               svcpt = svc->srv_part;
 
-                /* service threads can block for bulk, so this limits us
-                 * (arbitrarily) to recursing 1 stack frame per service.
-                 * Note that the problem with recursion is that we have to
-                 * unwind completely before our caller can resume. */
+               if (svcpt->scp_nthrs_running != 0)     /* I've recursed */
+                       continue;
 
-                svc->srv_threads_running++;
+               /* service threads can block for bulk, so this limits us
+                * (arbitrarily) to recursing 1 stack frame per service.
+                * Note that the problem with recursion is that we have to
+                * unwind completely before our caller can resume. */
 
-                do {
-                        rc = ptlrpc_server_handle_req_in(svc);
-                        rc |= ptlrpc_server_handle_reply(svc);
-                        rc |= ptlrpc_at_check_timed(svc);
-                        rc |= ptlrpc_server_handle_request(svc, NULL);
-                        rc |= (ptlrpc_server_post_idle_rqbds(svc) > 0);
-                        did_something |= rc;
-                } while (rc);
+               svcpt->scp_nthrs_running++;
 
-                svc->srv_threads_running--;
-        }
+               do {
+                       rc = ptlrpc_server_handle_req_in(svcpt);
+                       rc |= ptlrpc_server_handle_reply(svcpt);
+                       rc |= ptlrpc_at_check_timed(svcpt);
+                       rc |= ptlrpc_server_handle_request(svcpt, NULL);
+                       rc |= (ptlrpc_server_post_idle_rqbds(svcpt) > 0);
+                       did_something |= rc;
+               } while (rc);
+
+               svcpt->scp_nthrs_running--;
+       }
 
-        RETURN(did_something);
+       RETURN(did_something);
 }
 #define ptlrpc_stop_all_threads(s) do {} while (0)
 
 #else /* __KERNEL__ */
 
-/* Don't use daemonize, it removes fs struct from new thread (bug 418) */
-void ptlrpc_daemonize(char *name)
-{
-        struct fs_struct *fs = current->fs;
-
-        atomic_inc(&fs->count);
-        cfs_daemonize(name);
-        exit_fs(cfs_current());
-        current->fs = fs;
-        ll_set_fs_pwd(current->fs, init_task.fs->pwdmnt, init_task.fs->pwd);
-}
-
 static void
-ptlrpc_check_rqbd_pool(struct ptlrpc_service *svc)
+ptlrpc_check_rqbd_pool(struct ptlrpc_service_part *svcpt)
 {
-        int avail = svc->srv_nrqbd_receiving;
-        int low_water = test_req_buffer_pressure ? 0 :
-                        svc->srv_nbuf_per_group/2;
+       int avail = svcpt->scp_nrqbds_posted;
+       int low_water = test_req_buffer_pressure ? 0 :
+                       svcpt->scp_service->srv_nbuf_per_group / 2;
 
         /* NB I'm not locking; just looking. */
 
@@ -1390,38 +2059,132 @@ ptlrpc_check_rqbd_pool(struct ptlrpc_service *svc)
          * space. */
 
         if (avail <= low_water)
-                ptlrpc_grow_req_bufs(svc);
+               ptlrpc_grow_req_bufs(svcpt);
 
-        if (svc->srv_stats)
-                lprocfs_counter_add(svc->srv_stats, PTLRPC_REQBUF_AVAIL_CNTR,
-                                    avail);
+       if (svcpt->scp_service->srv_stats) {
+               lprocfs_counter_add(svcpt->scp_service->srv_stats,
+                                   PTLRPC_REQBUF_AVAIL_CNTR, avail);
+       }
 }
 
 static int
 ptlrpc_retry_rqbds(void *arg)
 {
-        struct ptlrpc_service *svc = (struct ptlrpc_service *)arg;
+       struct ptlrpc_service_part *svcpt = (struct ptlrpc_service_part *)arg;
+
+       svcpt->scp_rqbd_timeout = 0;
+       return -ETIMEDOUT;
+}
+
+static inline int
+ptlrpc_threads_enough(struct ptlrpc_service_part *svcpt)
+{
+       return svcpt->scp_nreqs_active <
+              svcpt->scp_nthrs_running - 1 -
+              (svcpt->scp_service->srv_ops.so_hpreq_handler != NULL);
+}
+
+/**
+ * allowed to create more threads
+ * user can call it w/o any lock but need to hold
+ * ptlrpc_service_part::scp_lock to get reliable result
+ */
+static inline int
+ptlrpc_threads_increasable(struct ptlrpc_service_part *svcpt)
+{
+       return svcpt->scp_nthrs_running +
+              svcpt->scp_nthrs_starting < svcpt->scp_service->srv_threads_max;
+}
+
+/**
+ * too many requests and allowed to create more threads
+ */
+static inline int
+ptlrpc_threads_need_create(struct ptlrpc_service_part *svcpt)
+{
+       return !ptlrpc_threads_enough(svcpt) &&
+               ptlrpc_threads_increasable(svcpt);
+}
+
+static inline int
+ptlrpc_thread_stopping(struct ptlrpc_thread *thread)
+{
+       return thread_is_stopping(thread) ||
+              thread->t_svcpt->scp_service->srv_is_stopping;
+}
+
+static inline int
+ptlrpc_rqbd_pending(struct ptlrpc_service_part *svcpt)
+{
+       return !cfs_list_empty(&svcpt->scp_rqbd_idle) &&
+              svcpt->scp_rqbd_timeout == 0;
+}
+
+static inline int
+ptlrpc_at_check(struct ptlrpc_service_part *svcpt)
+{
+       return svcpt->scp_at_check;
+}
+
+/**
+ * requests wait on preprocessing
+ * user can call it w/o any lock but need to hold
+ * ptlrpc_service_part::scp_lock to get reliable result
+ */
+static inline int
+ptlrpc_server_request_incoming(struct ptlrpc_service_part *svcpt)
+{
+       return !cfs_list_empty(&svcpt->scp_req_incoming);
+}
+
+static __attribute__((__noinline__)) int
+ptlrpc_wait_event(struct ptlrpc_service_part *svcpt,
+                 struct ptlrpc_thread *thread)
+{
+       /* Don't exit while there are replies to be handled */
+       struct l_wait_info lwi = LWI_TIMEOUT(svcpt->scp_rqbd_timeout,
+                                            ptlrpc_retry_rqbds, svcpt);
+
+       lc_watchdog_disable(thread->t_watchdog);
+
+       cfs_cond_resched();
+
+       l_wait_event_exclusive_head(svcpt->scp_waitq,
+                               ptlrpc_thread_stopping(thread) ||
+                               ptlrpc_server_request_incoming(svcpt) ||
+                               ptlrpc_server_request_pending(svcpt, 0) ||
+                               ptlrpc_rqbd_pending(svcpt) ||
+                               ptlrpc_at_check(svcpt), &lwi);
+
+       if (ptlrpc_thread_stopping(thread))
+               return -EINTR;
 
-        svc->srv_rqbd_timeout = 0;
-        return (-ETIMEDOUT);
+       lc_watchdog_touch(thread->t_watchdog,
+                         ptlrpc_server_get_timeout(svcpt));
+       return 0;
 }
 
+/**
+ * Main thread body for service threads.
+ * Waits in a loop waiting for new requests to process to appear.
+ * Every time an incoming requests is added to its queue, a waitq
+ * is woken up and one of the threads will handle it.
+ */
 static int ptlrpc_main(void *arg)
 {
-        struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
-        struct ptlrpc_service  *svc = data->svc;
-        struct ptlrpc_thread   *thread = data->thread;
-        struct obd_device      *dev = data->dev;
-        struct ptlrpc_reply_state *rs;
-        struct lc_watchdog     *watchdog;
+       struct ptlrpc_thread            *thread = (struct ptlrpc_thread *)arg;
+       struct ptlrpc_service_part      *svcpt = thread->t_svcpt;
+       struct ptlrpc_service           *svc = svcpt->scp_service;
+       struct ptlrpc_reply_state       *rs;
 #ifdef WITH_GROUP_INFO
-        struct group_info *ginfo = NULL;
+        cfs_group_info_t *ginfo = NULL;
 #endif
-        struct lu_env env;
+        struct lu_env *env;
         int counter = 0, rc = 0;
         ENTRY;
 
-        ptlrpc_daemonize(data->name);
+        thread->t_pid = cfs_curproc_pid();
+        cfs_daemonize_ctxt(thread->t_name);
 
 #if defined(HAVE_NODE_TO_CPUMASK) && defined(CONFIG_NUMA)
         /* we need to do this before any per-thread allocation is done so that
@@ -1429,208 +2192,369 @@ static int ptlrpc_main(void *arg)
         if (svc->srv_cpu_affinity) {
                 int cpu, num_cpu;
 
-                for (cpu = 0, num_cpu = 0; cpu < num_possible_cpus(); cpu++) {
+                for (cpu = 0, num_cpu = 0; cpu < cfs_num_possible_cpus();
+                     cpu++) {
                         if (!cpu_online(cpu))
                                 continue;
-                        if (num_cpu == thread->t_id % num_online_cpus())
+                        if (num_cpu == thread->t_id % cfs_num_online_cpus())
                                 break;
                         num_cpu++;
                 }
-                set_cpus_allowed(cfs_current(), node_to_cpumask(cpu_to_node(cpu)));
+                cfs_set_cpus_allowed(cfs_current(),
+                                     node_to_cpumask(cpu_to_node(cpu)));
         }
 #endif
 
 #ifdef WITH_GROUP_INFO
-        ginfo = groups_alloc(0);
+        ginfo = cfs_groups_alloc(0);
         if (!ginfo) {
                 rc = -ENOMEM;
                 goto out;
         }
 
-        set_current_groups(ginfo);
-        put_group_info(ginfo);
+        cfs_set_current_groups(ginfo);
+        cfs_put_group_info(ginfo);
 #endif
 
-        if (svc->srv_init != NULL) {
-                rc = svc->srv_init(thread);
+       if (svc->srv_ops.so_thr_init != NULL) {
+               rc = svc->srv_ops.so_thr_init(thread);
                 if (rc)
                         goto out;
         }
 
-        rc = lu_context_init(&env.le_ctx, svc->srv_ctx_tags);
+        OBD_ALLOC_PTR(env);
+        if (env == NULL) {
+                rc = -ENOMEM;
+                goto out_srv_fini;
+        }
+
+        rc = lu_context_init(&env->le_ctx,
+                             svc->srv_ctx_tags|LCT_REMEMBER|LCT_NOREF);
         if (rc)
                 goto out_srv_fini;
 
-        thread->t_env = &env;
-        env.le_ctx.lc_thread = thread;
+        thread->t_env = env;
+        env->le_ctx.lc_thread = thread;
+        env->le_ctx.lc_cookie = 0x6;
 
         /* Alloc reply state structure for this one */
-        OBD_ALLOC_GFP(rs, svc->srv_max_reply_size, CFS_ALLOC_STD);
+        OBD_ALLOC_LARGE(rs, svc->srv_max_reply_size);
         if (!rs) {
                 rc = -ENOMEM;
                 goto out_srv_fini;
         }
 
-        /* Record that the thread is running */
-        thread->t_flags = SVC_RUNNING;
-        /*
-         * wake up our creator. Note: @data is invalid after this point,
-         * because it's allocated on ptlrpc_start_thread() stack.
-         */
-        cfs_waitq_signal(&thread->t_ctl_waitq);
-
-        watchdog = lc_watchdog_add(max_t(int, obd_timeout, AT_OFF ? 0 :
-                                   at_get(&svc->srv_at_estimate)) *
-                                   svc->srv_watchdog_factor, NULL, NULL);
-
-        spin_lock(&svc->srv_lock);
-        svc->srv_threads_running++;
-        list_add(&rs->rs_list, &svc->srv_free_rs_list);
-        spin_unlock(&svc->srv_lock);
-        cfs_waitq_signal(&svc->srv_free_rs_waitq);
-
-        CDEBUG(D_NET, "service thread %d (#%d)started\n", thread->t_id,
-              svc->srv_threads_running);
-
-        /* XXX maintain a list of all managed devices: insert here */
-
-        while ((thread->t_flags & SVC_STOPPING) == 0 ||
-               svc->srv_n_difficult_replies != 0) {
-                /* Don't exit while there are replies to be handled */
-                struct l_wait_info lwi = LWI_TIMEOUT(svc->srv_rqbd_timeout,
-                                                     ptlrpc_retry_rqbds, svc);
-
-                lc_watchdog_disable(watchdog);
-
-                cond_resched();
-
-                l_wait_event_exclusive (svc->srv_waitq,
-                              ((thread->t_flags & SVC_STOPPING) != 0 &&
-                               svc->srv_n_difficult_replies == 0) ||
-                              (!list_empty(&svc->srv_idle_rqbds) &&
-                               svc->srv_rqbd_timeout == 0) ||
-                              !list_empty(&svc->srv_req_in_queue) ||
-                              !list_empty(&svc->srv_reply_queue) ||
-                              (!list_empty(&svc->srv_request_queue) &&
-                               (svc->srv_n_active_reqs <
-                                (svc->srv_threads_running - 1))) ||
-                              svc->srv_at_check,
-                              &lwi);
-
-                lc_watchdog_touch_ms(watchdog, max_t(int, obd_timeout,
-                                     AT_OFF ? 0 :
-                                     at_get(&svc->srv_at_estimate)) *
-                                     svc->srv_watchdog_factor);
-
-                ptlrpc_check_rqbd_pool(svc);
-
-                if ((svc->srv_threads_started < svc->srv_threads_max) &&
-                    (svc->srv_n_active_reqs >= (svc->srv_threads_started - 1))){
-                        /* Ignore return code - we tried... */
-                        ptlrpc_start_thread(dev, svc);
-                }
+       cfs_spin_lock(&svcpt->scp_lock);
 
-                if (!list_empty(&svc->srv_reply_queue))
-                        ptlrpc_server_handle_reply(svc);
+       LASSERT(thread_is_starting(thread));
+       thread_clear_flags(thread, SVC_STARTING);
 
-                if (!list_empty(&svc->srv_req_in_queue)) {
-                        /* Process all incoming reqs before handling any */
-                        ptlrpc_server_handle_req_in(svc);
-                        /* but limit ourselves in case of flood */
-                        if (counter++ < 1000)
-                                continue;
-                        counter = 0;
-                }
+       LASSERT(svcpt->scp_nthrs_starting == 1);
+       svcpt->scp_nthrs_starting--;
+
+       /* SVC_STOPPING may already be set here if someone else is trying
+        * to stop the service while this new thread has been dynamically
+        * forked. We still set SVC_RUNNING to let our creator know that
+        * we are now running, however we will exit as soon as possible */
+       thread_add_flags(thread, SVC_RUNNING);
+       svcpt->scp_nthrs_running++;
+       cfs_spin_unlock(&svcpt->scp_lock);
+
+       /* wake up our creator in case he's still waiting. */
+       cfs_waitq_signal(&thread->t_ctl_waitq);
+
+       thread->t_watchdog = lc_watchdog_add(ptlrpc_server_get_timeout(svcpt),
+                                            NULL, NULL);
+
+       cfs_spin_lock(&svcpt->scp_rep_lock);
+       cfs_list_add(&rs->rs_list, &svcpt->scp_rep_idle);
+       cfs_waitq_signal(&svcpt->scp_rep_waitq);
+       cfs_spin_unlock(&svcpt->scp_rep_lock);
 
-                if (svc->srv_at_check)
-                        ptlrpc_at_check_timed(svc);
+       CDEBUG(D_NET, "service thread %d (#%d) started\n", thread->t_id,
+              svcpt->scp_nthrs_running);
 
-                /* don't handle requests in the last thread */
-                if (!list_empty (&svc->srv_request_queue) &&
-                    (svc->srv_n_active_reqs < (svc->srv_threads_running - 1))) {
-                        lu_context_enter(&env.le_ctx);
-                        ptlrpc_server_handle_request(svc, thread);
-                        lu_context_exit(&env.le_ctx);
+       /* XXX maintain a list of all managed devices: insert here */
+       while (!ptlrpc_thread_stopping(thread)) {
+               if (ptlrpc_wait_event(svcpt, thread))
+                       break;
+
+               ptlrpc_check_rqbd_pool(svcpt);
+
+               if (ptlrpc_threads_need_create(svcpt)) {
+                       /* Ignore return code - we tried... */
+                       ptlrpc_start_thread(svcpt, 0);
+                }
+
+               /* Process all incoming reqs before handling any */
+               if (ptlrpc_server_request_incoming(svcpt)) {
+                       ptlrpc_server_handle_req_in(svcpt);
+                       /* but limit ourselves in case of flood */
+                       if (counter++ < 100)
+                               continue;
+                       counter = 0;
+               }
+
+               if (ptlrpc_at_check(svcpt))
+                       ptlrpc_at_check_timed(svcpt);
+
+               if (ptlrpc_server_request_pending(svcpt, 0)) {
+                       lu_context_enter(&env->le_ctx);
+                       ptlrpc_server_handle_request(svcpt, thread);
+                       lu_context_exit(&env->le_ctx);
                 }
 
-                if (!list_empty(&svc->srv_idle_rqbds) &&
-                    ptlrpc_server_post_idle_rqbds(svc) < 0) {
-                        /* I just failed to repost request buffers.  Wait
-                         * for a timeout (unless something else happens)
-                         * before I try again */
-                        svc->srv_rqbd_timeout = cfs_time_seconds(1)/10;
-                        CDEBUG(D_RPCTRACE,"Posted buffers: %d\n",
-                               svc->srv_nrqbd_receiving);
+               if (ptlrpc_rqbd_pending(svcpt) &&
+                   ptlrpc_server_post_idle_rqbds(svcpt) < 0) {
+                       /* I just failed to repost request buffers.
+                        * Wait for a timeout (unless something else
+                        * happens) before I try again */
+                       svcpt->scp_rqbd_timeout = cfs_time_seconds(1) / 10;
+                       CDEBUG(D_RPCTRACE, "Posted buffers: %d\n",
+                              svcpt->scp_nrqbds_posted);
                 }
         }
 
-        lc_watchdog_delete(watchdog);
+        lc_watchdog_delete(thread->t_watchdog);
+        thread->t_watchdog = NULL;
 
 out_srv_fini:
         /*
          * deconstruct service specific state created by ptlrpc_start_thread()
          */
-        if (svc->srv_done != NULL)
-                svc->srv_done(thread);
+       if (svc->srv_ops.so_thr_done != NULL)
+               svc->srv_ops.so_thr_done(thread);
 
-        lu_context_fini(&env.le_ctx);
+        if (env != NULL) {
+                lu_context_fini(&env->le_ctx);
+                OBD_FREE_PTR(env);
+        }
 out:
-        CDEBUG(D_NET, "service thread %d exiting: rc %d\n", thread->t_id, rc);
+        CDEBUG(D_RPCTRACE, "service thread [ %p : %u ] %d exiting: rc %d\n",
+               thread, thread->t_pid, thread->t_id, rc);
+
+       cfs_spin_lock(&svcpt->scp_lock);
+       if (thread_test_and_clear_flags(thread, SVC_STARTING))
+               svcpt->scp_nthrs_starting--;
+
+       if (thread_test_and_clear_flags(thread, SVC_RUNNING)) {
+               /* must know immediately */
+               svcpt->scp_nthrs_running--;
+       }
+
+       thread->t_id = rc;
+       thread_add_flags(thread, SVC_STOPPED);
 
-        spin_lock(&svc->srv_lock);
-        svc->srv_threads_running--; /* must know immediately */
-        thread->t_id = rc;
-        thread->t_flags = SVC_STOPPED;
+       cfs_waitq_signal(&thread->t_ctl_waitq);
+       cfs_spin_unlock(&svcpt->scp_lock);
+
+       return rc;
+}
+
+struct ptlrpc_hr_args {
+        int                       thread_index;
+        int                       cpu_index;
+        struct ptlrpc_hr_service *hrs;
+};
+
+static int hrt_dont_sleep(struct ptlrpc_hr_thread *t,
+                          cfs_list_t *replies)
+{
+        int result;
+
+        cfs_spin_lock(&t->hrt_lock);
+        cfs_list_splice_init(&t->hrt_queue, replies);
+        result = cfs_test_bit(HRT_STOPPING, &t->hrt_flags) ||
+                !cfs_list_empty(replies);
+        cfs_spin_unlock(&t->hrt_lock);
+        return result;
+}
+
+/**
+ * Main body of "handle reply" function.
+ * It processes acked reply states
+ */
+static int ptlrpc_hr_main(void *arg)
+{
+        struct ptlrpc_hr_args * hr_args = arg;
+        struct ptlrpc_hr_service *hr = hr_args->hrs;
+        struct ptlrpc_hr_thread *t = &hr->hr_threads[hr_args->thread_index];
+        char threadname[20];
+        CFS_LIST_HEAD(replies);
+
+        snprintf(threadname, sizeof(threadname),
+                 "ptlrpc_hr_%d", hr_args->thread_index);
+
+        cfs_daemonize_ctxt(threadname);
+#if defined(CONFIG_NUMA) && defined(HAVE_NODE_TO_CPUMASK)
+        cfs_set_cpus_allowed(cfs_current(),
+                             node_to_cpumask(cpu_to_node(hr_args->cpu_index)));
+#endif
+        cfs_set_bit(HRT_RUNNING, &t->hrt_flags);
+        cfs_waitq_signal(&t->hrt_wait);
+
+        while (!cfs_test_bit(HRT_STOPPING, &t->hrt_flags)) {
+
+                l_wait_condition(t->hrt_wait, hrt_dont_sleep(t, &replies));
+                while (!cfs_list_empty(&replies)) {
+                        struct ptlrpc_reply_state *rs;
+
+                        rs = cfs_list_entry(replies.prev,
+                                            struct ptlrpc_reply_state,
+                                            rs_list);
+                        cfs_list_del_init(&rs->rs_list);
+                        ptlrpc_handle_rs(rs);
+                }
+        }
+
+        cfs_clear_bit(HRT_RUNNING, &t->hrt_flags);
+        cfs_complete(&t->hrt_completion);
+
+        return 0;
+}
+
+static int ptlrpc_start_hr_thread(struct ptlrpc_hr_service *hr, int n, int cpu)
+{
+        struct ptlrpc_hr_thread *t = &hr->hr_threads[n];
+        struct ptlrpc_hr_args args;
+        int rc;
+        ENTRY;
 
-        cfs_waitq_signal(&thread->t_ctl_waitq);
-        spin_unlock(&svc->srv_lock);
+        args.thread_index = n;
+        args.cpu_index = cpu;
+        args.hrs = hr;
 
+        rc = cfs_create_thread(ptlrpc_hr_main, (void*)&args, CFS_DAEMON_FLAGS);
+        if (rc < 0) {
+                cfs_complete(&t->hrt_completion);
+                GOTO(out, rc);
+        }
+        l_wait_condition(t->hrt_wait, cfs_test_bit(HRT_RUNNING, &t->hrt_flags));
+        RETURN(0);
+ out:
         return rc;
 }
 
-static void ptlrpc_stop_thread(struct ptlrpc_service *svc,
-                               struct ptlrpc_thread *thread)
+static void ptlrpc_stop_hr_thread(struct ptlrpc_hr_thread *t)
 {
-        struct l_wait_info lwi = { 0 };
         ENTRY;
 
-        CDEBUG(D_RPCTRACE, "Stopping thread %p\n", thread);
-        spin_lock(&svc->srv_lock);
-        thread->t_flags = SVC_STOPPING;
-        spin_unlock(&svc->srv_lock);
+        cfs_set_bit(HRT_STOPPING, &t->hrt_flags);
+        cfs_waitq_signal(&t->hrt_wait);
+        cfs_wait_for_completion(&t->hrt_completion);
 
-        cfs_waitq_broadcast(&svc->srv_waitq);
-        l_wait_event(thread->t_ctl_waitq, (thread->t_flags & SVC_STOPPED),
-                     &lwi);
+        EXIT;
+}
+
+static void ptlrpc_stop_hr_threads(struct ptlrpc_hr_service *hrs)
+{
+        int n;
+        ENTRY;
 
-        spin_lock(&svc->srv_lock);
-        list_del(&thread->t_link);
-        spin_unlock(&svc->srv_lock);
+        for (n = 0; n < hrs->hr_n_threads; n++)
+                ptlrpc_stop_hr_thread(&hrs->hr_threads[n]);
 
-        OBD_FREE_PTR(thread);
         EXIT;
 }
 
-void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
+static int ptlrpc_start_hr_threads(struct ptlrpc_hr_service *hr)
 {
-        struct ptlrpc_thread *thread;
+        int rc = -ENOMEM;
+        int n, cpu, threads_started = 0;
         ENTRY;
 
-        spin_lock(&svc->srv_lock);
-        while (!list_empty(&svc->srv_threads)) {
-                thread = list_entry(svc->srv_threads.next,
-                                    struct ptlrpc_thread, t_link);
+        LASSERT(hr != NULL);
+        LASSERT(hr->hr_n_threads > 0);
 
-                spin_unlock(&svc->srv_lock);
-                ptlrpc_stop_thread(svc, thread);
-                spin_lock(&svc->srv_lock);
+        for (n = 0, cpu = 0; n < hr->hr_n_threads; n++) {
+#if defined(CONFIG_SMP) && defined(HAVE_NODE_TO_CPUMASK)
+                while (!cpu_online(cpu)) {
+                        cpu++;
+                        if (cpu >= cfs_num_possible_cpus())
+                                cpu = 0;
+                }
+#endif
+                rc = ptlrpc_start_hr_thread(hr, n, cpu);
+                if (rc != 0)
+                        break;
+                threads_started++;
+                cpu++;
+        }
+        if (threads_started == 0) {
+                CERROR("No reply handling threads started\n");
+                RETURN(-ESRCH);
         }
+        if (threads_started < hr->hr_n_threads) {
+                CWARN("Started only %d reply handling threads from %d\n",
+                      threads_started, hr->hr_n_threads);
+                hr->hr_n_threads = threads_started;
+        }
+        RETURN(0);
+}
 
-        spin_unlock(&svc->srv_lock);
-        EXIT;
+static void ptlrpc_svcpt_stop_threads(struct ptlrpc_service_part *svcpt)
+{
+       struct l_wait_info      lwi = { 0 };
+       struct ptlrpc_thread    *thread;
+       CFS_LIST_HEAD           (zombie);
+
+       ENTRY;
+
+       CDEBUG(D_INFO, "Stopping threads for service %s\n",
+              svcpt->scp_service->srv_name);
+
+       cfs_spin_lock(&svcpt->scp_lock);
+       /* let the thread know that we would like it to stop asap */
+       list_for_each_entry(thread, &svcpt->scp_threads, t_link) {
+               CDEBUG(D_INFO, "Stopping thread %s #%u\n",
+                      svcpt->scp_service->srv_thread_name, thread->t_id);
+               thread_add_flags(thread, SVC_STOPPING);
+       }
+
+       cfs_waitq_broadcast(&svcpt->scp_waitq);
+
+       while (!cfs_list_empty(&svcpt->scp_threads)) {
+               thread = cfs_list_entry(svcpt->scp_threads.next,
+                                       struct ptlrpc_thread, t_link);
+               if (thread_is_stopped(thread)) {
+                       cfs_list_del(&thread->t_link);
+                       cfs_list_add(&thread->t_link, &zombie);
+                       continue;
+               }
+               cfs_spin_unlock(&svcpt->scp_lock);
+
+               CDEBUG(D_INFO, "waiting for stopping-thread %s #%u\n",
+                      svcpt->scp_service->srv_thread_name, thread->t_id);
+               l_wait_event(thread->t_ctl_waitq,
+                            thread_is_stopped(thread), &lwi);
+
+               cfs_spin_lock(&svcpt->scp_lock);
+       }
+
+       cfs_spin_unlock(&svcpt->scp_lock);
+
+       while (!cfs_list_empty(&zombie)) {
+               thread = cfs_list_entry(zombie.next,
+                                       struct ptlrpc_thread, t_link);
+               cfs_list_del(&thread->t_link);
+               OBD_FREE_PTR(thread);
+       }
+       EXIT;
 }
 
-int ptlrpc_start_threads(struct obd_device *dev, struct ptlrpc_service *svc)
+/**
+ * Stops all threads of a particular service \a svc
+ */
+void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
+{
+       ENTRY;
+
+       if (svc != NULL && svc->srv_part != NULL)
+               ptlrpc_svcpt_stop_threads(svc->srv_part);
+       EXIT;
+}
+
+int ptlrpc_start_threads(struct ptlrpc_service *svc)
 {
         int i, rc = 0;
         ENTRY;
@@ -1639,100 +2563,205 @@ int ptlrpc_start_threads(struct obd_device *dev, struct ptlrpc_service *svc)
            ptlrpc_server_handle_request */
         LASSERT(svc->srv_threads_min >= 2);
         for (i = 0; i < svc->srv_threads_min; i++) {
-                rc = ptlrpc_start_thread(dev, svc);
+               rc = ptlrpc_start_thread(svc->srv_part, 1);
                 /* We have enough threads, don't start more.  b=15759 */
-                if (rc == -EMFILE)
+                if (rc == -EMFILE) {
+                        rc = 0;
                         break;
+                }
                 if (rc) {
                         CERROR("cannot start %s thread #%d: rc %d\n",
                                svc->srv_thread_name, i, rc);
                         ptlrpc_stop_all_threads(svc);
+                        break;
                 }
         }
         RETURN(rc);
 }
 
-int ptlrpc_start_thread(struct obd_device *dev, struct ptlrpc_service *svc)
+int ptlrpc_start_thread(struct ptlrpc_service_part *svcpt, int wait)
 {
-        struct l_wait_info lwi = { 0 };
-        struct ptlrpc_svc_data d;
-        struct ptlrpc_thread *thread;
-        char name[32];
-        int id, rc;
-        ENTRY;
+       struct l_wait_info      lwi = { 0 };
+       struct ptlrpc_thread    *thread;
+       struct ptlrpc_service   *svc = svcpt->scp_service;
+       int                     rc;
+       ENTRY;
+
+       LASSERT(svcpt != NULL);
+
+       CDEBUG(D_RPCTRACE, "%s started %d min %d max %d\n",
+              svc->srv_name, svcpt->scp_nthrs_running,
+              svc->srv_threads_min, svc->srv_threads_max);
+
+ again:
+       if (unlikely(svc->srv_is_stopping))
+               RETURN(-ESRCH);
+
+       if (!ptlrpc_threads_increasable(svcpt) ||
+           (OBD_FAIL_CHECK(OBD_FAIL_TGT_TOOMANY_THREADS) &&
+            svcpt->scp_nthrs_running == svc->srv_threads_min - 1))
+               RETURN(-EMFILE);
+
+       OBD_ALLOC_PTR(thread);
+       if (thread == NULL)
+               RETURN(-ENOMEM);
+       cfs_waitq_init(&thread->t_ctl_waitq);
+
+       cfs_spin_lock(&svcpt->scp_lock);
+       if (!ptlrpc_threads_increasable(svcpt)) {
+               cfs_spin_unlock(&svcpt->scp_lock);
+               OBD_FREE_PTR(thread);
+               RETURN(-EMFILE);
+       }
+
+       if (svcpt->scp_nthrs_starting != 0) {
+               /* serialize starting because some modules (obdfilter)
+                * might require unique and contiguous t_id */
+               LASSERT(svcpt->scp_nthrs_starting == 1);
+               cfs_spin_unlock(&svcpt->scp_lock);
+               OBD_FREE_PTR(thread);
+               if (wait) {
+                       CDEBUG(D_INFO, "Waiting for creating thread %s #%d\n",
+                              svc->srv_thread_name, svcpt->scp_thr_nextid);
+                       cfs_schedule();
+                       goto again;
+               }
+
+               CDEBUG(D_INFO, "Creating thread %s #%d race, retry later\n",
+                      svc->srv_thread_name, svcpt->scp_thr_nextid);
+               RETURN(-EAGAIN);
+       }
+
+       svcpt->scp_nthrs_starting++;
+       thread->t_id = svcpt->scp_thr_nextid++;
+       thread_add_flags(thread, SVC_STARTING);
+       thread->t_svcpt = svcpt;
+
+       cfs_list_add(&thread->t_link, &svcpt->scp_threads);
+       cfs_spin_unlock(&svcpt->scp_lock);
+
+       snprintf(thread->t_name, PTLRPC_THR_NAME_LEN,
+                "%s_%02d", svc->srv_thread_name, thread->t_id);
+
+       CDEBUG(D_RPCTRACE, "starting thread '%s'\n", thread->t_name);
+       /*
+        * CLONE_VM and CLONE_FILES just avoid a needless copy, because we
+        * just drop the VM and FILES in cfs_daemonize_ctxt() right away.
+        */
+       rc = cfs_create_thread(ptlrpc_main, thread, CFS_DAEMON_FLAGS);
+       if (rc < 0) {
+               CERROR("cannot start thread '%s': rc %d\n",
+                      thread->t_name, rc);
+               cfs_spin_lock(&svcpt->scp_lock);
+               cfs_list_del(&thread->t_link);
+               --svcpt->scp_nthrs_starting;
+               cfs_spin_unlock(&svcpt->scp_lock);
 
-        CDEBUG(D_RPCTRACE, "%s started %d min %d max %d running %d\n",
-               svc->srv_name, svc->srv_threads_started, svc->srv_threads_min,
-               svc->srv_threads_max, svc->srv_threads_running);
-        if (unlikely(svc->srv_threads_started >= svc->srv_threads_max) ||
-            (OBD_FAIL_CHECK(OBD_FAIL_TGT_TOOMANY_THREADS) &&
-             svc->srv_threads_started == svc->srv_threads_min - 1))
-                RETURN(-EMFILE);
+                OBD_FREE(thread, sizeof(*thread));
+                RETURN(rc);
+        }
 
-        OBD_ALLOC_PTR(thread);
-        if (thread == NULL)
-                RETURN(-ENOMEM);
-        cfs_waitq_init(&thread->t_ctl_waitq);
+       if (!wait)
+               RETURN(0);
 
-        spin_lock(&svc->srv_lock);
-        if (svc->srv_threads_started >= svc->srv_threads_max) {
-                spin_unlock(&svc->srv_lock);
-                OBD_FREE_PTR(thread);
-                RETURN(-EMFILE);
-        }
-        list_add(&thread->t_link, &svc->srv_threads);
-        id = svc->srv_threads_started++;
-        spin_unlock(&svc->srv_lock);
+        l_wait_event(thread->t_ctl_waitq,
+                     thread_is_running(thread) || thread_is_stopped(thread),
+                     &lwi);
 
-        thread->t_id = id;
-        sprintf(name, "%s_%02d", svc->srv_thread_name, id);
-        d.dev = dev;
-        d.svc = svc;
-        d.name = name;
-        d.thread = thread;
+        rc = thread_is_stopped(thread) ? thread->t_id : 0;
+        RETURN(rc);
+}
 
-        CDEBUG(D_RPCTRACE, "starting thread '%s'\n", name);
+int ptlrpc_hr_init(void)
+{
+        int i;
+        int n_cpus = cfs_num_online_cpus();
+        struct ptlrpc_hr_service *hr;
+        int size;
+        int rc;
+        ENTRY;
 
-          /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
-         * just drop the VM and FILES in ptlrpc_daemonize() right away.
-         */
-        rc = cfs_kernel_thread(ptlrpc_main, &d, CLONE_VM | CLONE_FILES);
-        if (rc < 0) {
-                CERROR("cannot start thread '%s': rc %d\n", name, rc);
+        LASSERT(ptlrpc_hr == NULL);
 
-                spin_lock(&svc->srv_lock);
-                list_del(&thread->t_link);
-                --svc->srv_threads_started;
-                spin_unlock(&svc->srv_lock);
+        size = offsetof(struct ptlrpc_hr_service, hr_threads[n_cpus]);
+        OBD_ALLOC(hr, size);
+        if (hr == NULL)
+                RETURN(-ENOMEM);
+        for (i = 0; i < n_cpus; i++) {
+                struct ptlrpc_hr_thread *t = &hr->hr_threads[i];
 
-                OBD_FREE(thread, sizeof(*thread));
-                RETURN(rc);
+                cfs_spin_lock_init(&t->hrt_lock);
+                cfs_waitq_init(&t->hrt_wait);
+                CFS_INIT_LIST_HEAD(&t->hrt_queue);
+                cfs_init_completion(&t->hrt_completion);
         }
-        l_wait_event(thread->t_ctl_waitq,
-                     thread->t_flags & (SVC_RUNNING | SVC_STOPPED), &lwi);
+        hr->hr_n_threads = n_cpus;
+        hr->hr_size = size;
+        ptlrpc_hr = hr;
 
-        rc = (thread->t_flags & SVC_STOPPED) ? thread->t_id : 0;
+        rc = ptlrpc_start_hr_threads(hr);
+        if (rc) {
+                OBD_FREE(hr, hr->hr_size);
+                ptlrpc_hr = NULL;
+        }
         RETURN(rc);
 }
-#endif
+
+void ptlrpc_hr_fini(void)
+{
+        if (ptlrpc_hr != NULL) {
+                ptlrpc_stop_hr_threads(ptlrpc_hr);
+                OBD_FREE(ptlrpc_hr, ptlrpc_hr->hr_size);
+                ptlrpc_hr = NULL;
+        }
+}
+
+#endif /* __KERNEL__ */
+
+/**
+ * Wait until all already scheduled replies are processed.
+ */
+static void ptlrpc_wait_replies(struct ptlrpc_service_part *svcpt)
+{
+       while (1) {
+               int rc;
+               struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(10),
+                                                    NULL, NULL);
+
+               rc = l_wait_event(svcpt->scp_waitq,
+                    cfs_atomic_read(&svcpt->scp_nreps_difficult) == 0, &lwi);
+               if (rc == 0)
+                       break;
+               CWARN("Unexpectedly long timeout %s %p\n",
+                     svcpt->scp_service->srv_name, svcpt->scp_service);
+       }
+}
 
 int ptlrpc_unregister_service(struct ptlrpc_service *service)
 {
-        int                   rc;
-        struct l_wait_info    lwi;
-        struct list_head     *tmp;
-        struct ptlrpc_reply_state *rs, *t;
-        ENTRY;
+       struct l_wait_info              lwi;
+       struct ptlrpc_service_part      *svcpt;
+       struct ptlrpc_reply_state       *rs;
+       struct ptlrpc_reply_state       *t;
+       struct ptlrpc_at_array          *array;
+       cfs_list_t                      *tmp;
+       int                             rc;
+       ENTRY;
+
+       service->srv_is_stopping = 1;
+       svcpt = service->srv_part;
 
-        service->srv_is_stopping = 1;
-        cfs_timer_disarm(&service->srv_at_timer);
+       if (svcpt == NULL || /* no instance of ptlrpc_service_part */
+           svcpt->scp_service == NULL) /* it's not fully initailzed */
+               GOTO(out, rc = 0);
 
-        ptlrpc_stop_all_threads(service);
-        LASSERT(list_empty(&service->srv_threads));
+       cfs_timer_disarm(&svcpt->scp_at_timer);
 
-        spin_lock (&ptlrpc_all_services_lock);
-        list_del_init (&service->srv_list);
-        spin_unlock (&ptlrpc_all_services_lock);
+       ptlrpc_stop_all_threads(service);
+
+        cfs_spin_lock (&ptlrpc_all_services_lock);
+        cfs_list_del_init (&service->srv_list);
+        cfs_spin_unlock (&ptlrpc_all_services_lock);
 
         ptlrpc_lprocfs_unregister_service(service);
 
@@ -1745,12 +2774,12 @@ int ptlrpc_unregister_service(struct ptlrpc_service *service)
         rc = LNetClearLazyPortal(service->srv_req_portal);
         LASSERT (rc == 0);
 
-        /* Unlink all the request buffers.  This forces a 'final' event with
-         * its 'unlink' flag set for each posted rqbd */
-        list_for_each(tmp, &service->srv_active_rqbds) {
+       /* Unlink all the request buffers.  This forces a 'final' event with
+        * its 'unlink' flag set for each posted rqbd */
+       cfs_list_for_each(tmp, &svcpt->scp_rqbd_posted) {
                 struct ptlrpc_request_buffer_desc *rqbd =
-                        list_entry(tmp, struct ptlrpc_request_buffer_desc,
-                                   rqbd_list);
+                        cfs_list_entry(tmp, struct ptlrpc_request_buffer_desc,
+                                       rqbd_list);
 
                 rc = LNetMDUnlink(rqbd->rqbd_md_h);
                 LASSERT (rc == 0 || rc == -ENOENT);
@@ -1759,138 +2788,146 @@ int ptlrpc_unregister_service(struct ptlrpc_service *service)
         /* Wait for the network to release any buffers it's currently
          * filling */
         for (;;) {
-                spin_lock(&service->srv_lock);
-                rc = service->srv_nrqbd_receiving;
-                spin_unlock(&service->srv_lock);
+               cfs_spin_lock(&svcpt->scp_lock);
+               rc = svcpt->scp_nrqbds_posted;
+               cfs_spin_unlock(&svcpt->scp_lock);
 
                 if (rc == 0)
                         break;
 
                 /* Network access will complete in finite time but the HUGE
                  * timeout lets us CWARN for visibility of sluggish NALs */
-                lwi = LWI_TIMEOUT(cfs_time_seconds(LONG_UNLINK), NULL, NULL);
-                rc = l_wait_event(service->srv_waitq,
-                                  service->srv_nrqbd_receiving == 0,
-                                  &lwi);
-                if (rc == -ETIMEDOUT)
-                        CWARN("Service %s waiting for request buffers\n",
-                              service->srv_name);
-        }
-
-        /* schedule all outstanding replies to terminate them */
-        spin_lock(&service->srv_lock);
-        while (!list_empty(&service->srv_active_replies)) {
-                struct ptlrpc_reply_state *rs =
-                        list_entry(service->srv_active_replies.next,
-                                   struct ptlrpc_reply_state, rs_list);
-                ptlrpc_schedule_difficult_reply(rs);
-        }
-        spin_unlock(&service->srv_lock);
-
-        /* purge the request queue.  NB No new replies (rqbds all unlinked)
-         * and no service threads, so I'm the only thread noodling the
-         * request queue now */
-        while (!list_empty(&service->srv_req_in_queue)) {
-                struct ptlrpc_request *req =
-                        list_entry(service->srv_req_in_queue.next,
-                                   struct ptlrpc_request,
-                                   rq_list);
-
-                list_del(&req->rq_list);
-                service->srv_n_queued_reqs--;
-                service->srv_n_active_reqs++;
-                ptlrpc_server_finish_request(req);
-        }
-        while (!list_empty(&service->srv_request_queue)) {
-                struct ptlrpc_request *req =
-                        list_entry(service->srv_request_queue.next,
-                                   struct ptlrpc_request,
-                                   rq_list);
-
-                list_del(&req->rq_list);
-                service->srv_n_queued_reqs--;
-                service->srv_n_active_reqs++;
-
-                ptlrpc_server_finish_request(req);
-        }
-        LASSERT(service->srv_n_queued_reqs == 0);
-        LASSERT(service->srv_n_active_reqs == 0);
-        LASSERT(service->srv_n_history_rqbds == 0);
-        LASSERT(list_empty(&service->srv_active_rqbds));
-
-        /* Now free all the request buffers since nothing references them
-         * any more... */
-        while (!list_empty(&service->srv_idle_rqbds)) {
-                struct ptlrpc_request_buffer_desc *rqbd =
-                        list_entry(service->srv_idle_rqbds.next,
-                                   struct ptlrpc_request_buffer_desc,
-                                   rqbd_list);
-
-                ptlrpc_free_rqbd(rqbd);
-        }
-
-        /* wait for all outstanding replies to complete (they were
-         * scheduled having been flagged to abort above) */
-        while (atomic_read(&service->srv_outstanding_replies) != 0) {
-                struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(10), NULL, NULL);
-
-                rc = l_wait_event(service->srv_waitq,
-                                  !list_empty(&service->srv_reply_queue), &lwi);
-                LASSERT(rc == 0 || rc == -ETIMEDOUT);
-
-                if (rc == 0) {
-                        ptlrpc_server_handle_reply(service);
-                        continue;
-                }
-                CWARN("Unexpectedly long timeout %p\n", service);
-        }
-
-        list_for_each_entry_safe(rs, t, &service->srv_free_rs_list, rs_list) {
-                list_del(&rs->rs_list);
-                OBD_FREE(rs, service->srv_max_reply_size);
-        }
-
-        /* In case somebody rearmed this in the meantime */
-        cfs_timer_disarm(&service->srv_at_timer);
-
-        OBD_FREE_PTR(service);
-        RETURN(0);
+                lwi = LWI_TIMEOUT_INTERVAL(cfs_time_seconds(LONG_UNLINK),
+                                           cfs_time_seconds(1), NULL, NULL);
+               rc = l_wait_event(svcpt->scp_waitq,
+                                 svcpt->scp_nrqbds_posted == 0, &lwi);
+               if (rc == -ETIMEDOUT)
+                       CWARN("Service %s waiting for request buffers\n",
+                             service->srv_name);
+       }
+
+       /* schedule all outstanding replies to terminate them */
+       cfs_spin_lock(&svcpt->scp_rep_lock);
+       while (!cfs_list_empty(&svcpt->scp_rep_active)) {
+               struct ptlrpc_reply_state *rs =
+                       cfs_list_entry(svcpt->scp_rep_active.next,
+                                      struct ptlrpc_reply_state, rs_list);
+               cfs_spin_lock(&rs->rs_lock);
+               ptlrpc_schedule_difficult_reply(rs);
+               cfs_spin_unlock(&rs->rs_lock);
+       }
+       cfs_spin_unlock(&svcpt->scp_rep_lock);
+
+       /* purge the request queue.  NB No new replies (rqbds all unlinked)
+        * and no service threads, so I'm the only thread noodling the
+        * request queue now */
+       while (!cfs_list_empty(&svcpt->scp_req_incoming)) {
+               struct ptlrpc_request *req =
+                       cfs_list_entry(svcpt->scp_req_incoming.next,
+                                      struct ptlrpc_request,
+                                      rq_list);
+
+               cfs_list_del(&req->rq_list);
+               svcpt->scp_nreqs_incoming--;
+               svcpt->scp_nreqs_active++;
+               ptlrpc_server_finish_request(svcpt, req);
+       }
+       while (ptlrpc_server_request_pending(svcpt, 1)) {
+               struct ptlrpc_request *req;
+
+               req = ptlrpc_server_request_get(svcpt, 1);
+               cfs_list_del(&req->rq_list);
+               svcpt->scp_nreqs_active++;
+               ptlrpc_server_finish_request(svcpt, req);
+       }
+       LASSERT(svcpt->scp_nreqs_incoming == 0);
+       LASSERT(svcpt->scp_nreqs_active == 0);
+       LASSERT(svcpt->scp_hist_nrqbds == 0);
+       LASSERT(cfs_list_empty(&svcpt->scp_rqbd_posted));
+
+       /* Now free all the request buffers since nothing references them
+        * any more... */
+       while (!cfs_list_empty(&svcpt->scp_rqbd_idle)) {
+               struct ptlrpc_request_buffer_desc *rqbd =
+                       cfs_list_entry(svcpt->scp_rqbd_idle.next,
+                                      struct ptlrpc_request_buffer_desc,
+                                      rqbd_list);
+
+               ptlrpc_free_rqbd(rqbd);
+       }
+
+       ptlrpc_wait_replies(svcpt);
+
+       cfs_list_for_each_entry_safe(rs, t, &svcpt->scp_rep_idle, rs_list) {
+               cfs_list_del(&rs->rs_list);
+               OBD_FREE_LARGE(rs, service->srv_max_reply_size);
+       }
+
+       /* In case somebody rearmed this in the meantime */
+       cfs_timer_disarm(&svcpt->scp_at_timer);
+
+       array = &svcpt->scp_at_array;
+        if (array->paa_reqs_array != NULL) {
+                OBD_FREE(array->paa_reqs_array,
+                         sizeof(cfs_list_t) * array->paa_size);
+                array->paa_reqs_array = NULL;
+        }
+
+        if (array->paa_reqs_count != NULL) {
+                OBD_FREE(array->paa_reqs_count,
+                         sizeof(__u32) * array->paa_size);
+                array->paa_reqs_count= NULL;
+        }
+
+       OBD_FREE_PTR(svcpt);
+ out:
+       OBD_FREE_PTR(service);
+       RETURN(0);
 }
 
-/* Returns 0 if the service is healthy.
+/**
+ * Returns 0 if the service is healthy.
  *
  * Right now, it just checks to make sure that requests aren't languishing
  * in the queue.  We'll use this health check to govern whether a node needs
  * to be shot, so it's intentionally non-aggressive. */
 int ptlrpc_service_health_check(struct ptlrpc_service *svc)
 {
-        struct ptlrpc_request *request;
-        struct timeval         right_now;
-        long                   timediff;
-
-        if (svc == NULL)
-                return 0;
-
-        do_gettimeofday(&right_now);
-
-        spin_lock(&svc->srv_lock);
-        if (list_empty(&svc->srv_request_queue)) {
-                spin_unlock(&svc->srv_lock);
-                return 0;
-        }
-
-        /* How long has the next entry been waiting? */
-        request = list_entry(svc->srv_request_queue.next,
-                             struct ptlrpc_request, rq_list);
-        timediff = cfs_timeval_sub(&right_now, &request->rq_arrival_time, NULL);
-        spin_unlock(&svc->srv_lock);
-
-        if ((timediff / ONE_MILLION) > (AT_OFF ? obd_timeout * 3/2 :
-                                        at_max)) {
-                CERROR("%s: unhealthy - request has been waiting %lds\n",
-                       svc->srv_name, timediff / ONE_MILLION);
-                return (-1);
-        }
-
-        return 0;
+       struct ptlrpc_service_part      *svcpt;
+       struct ptlrpc_request           *request;
+       struct timeval                  right_now;
+       long                            timediff;
+
+       if (svc == NULL || svc->srv_part == NULL)
+               return 0;
+
+       cfs_gettimeofday(&right_now);
+
+       svcpt = svc->srv_part;
+       cfs_spin_lock(&svcpt->scp_req_lock);
+       if (!ptlrpc_server_request_pending(svcpt, 1)) {
+               cfs_spin_unlock(&svcpt->scp_req_lock);
+               return 0;
+       }
+
+       /* How long has the next entry been waiting? */
+       if (cfs_list_empty(&svcpt->scp_req_pending)) {
+               request = cfs_list_entry(svcpt->scp_hreq_pending.next,
+                                        struct ptlrpc_request, rq_list);
+       } else {
+               request = cfs_list_entry(svcpt->scp_req_pending.next,
+                                        struct ptlrpc_request, rq_list);
+       }
+
+       timediff = cfs_timeval_sub(&right_now, &request->rq_arrival_time, NULL);
+       cfs_spin_unlock(&svcpt->scp_req_lock);
+
+       if ((timediff / ONE_MILLION) >
+           (AT_OFF ? obd_timeout * 3 / 2 : at_max)) {
+               CERROR("%s: unhealthy - request has been waiting %lds\n",
+                      svcpt->scp_service->srv_name, timediff / ONE_MILLION);
+               return -1;
+       }
+
+       return 0;
 }