From 98ee7e0be008f4c3c09f3c6d59884169ee7edd54 Mon Sep 17 00:00:00 2001
From: johann <johann>
Date: Fri, 27 Mar 2009 09:35:23 +0000
Subject: [PATCH] Branch b1_8 b=18577 i=shadow i=hongchao

create_count always drops to the min value (=32) because grow_count
is being changed before the precreate RPC completes.
---
 lustre/ChangeLog        |  5 +++++
 lustre/osc/osc_create.c | 24 ++++++++++++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lustre/ChangeLog b/lustre/ChangeLog
index ff8aca4..1c8e74a 100644
--- a/lustre/ChangeLog
+++ b/lustre/ChangeLog
@@ -137,6 +137,11 @@ Description: Assertion failure in ldlm_lock_put
 Details    : Do not put cancelled locks into replay list, hold references on
 	     locks in replay list
 
+Severity   : normal
+Bugzilla   : 18577
+Description: 1.6.5 mdsrate performance is slower than 1.4.11/12 (MDS is not cpu bound!)
+Details    : create_count always drops to the min value (=32) because grow_count
+	     is being changed before the precreate RPC completes.
 
 -------------------------------------------------------------------------------
 2008-12-31 Sun Microsystems, Inc.
diff --git a/lustre/osc/osc_create.c b/lustre/osc/osc_create.c
index 0edf767..3909c75 100644
--- a/lustre/osc/osc_create.c
+++ b/lustre/osc/osc_create.c
@@ -84,11 +84,26 @@ static int osc_interpret_create(struct ptlrpc_request *req, void *data, int rc)
                 if (body) {
                         int diff = body->oa.o_id - oscc->oscc_last_id;
 
-                        if (diff < oscc->oscc_grow_count)
-                                oscc->oscc_grow_count =
-                                        max(diff/3, OST_MIN_PRECREATE);
-                        else
+                        /* oscc_internal_create() stores the original value of
+                         * grow_count in rq_async_args.space[0].
+                         * We can't compare against oscc_grow_count directly,
+                         * because it may have been increased while the RPC
+                         * is in flight, so we would always find ourselves
+                         * having created fewer objects and decreasing the
+                         * precreate request size.  b=18577 */
+                        if (diff < (int) req->rq_async_args.space[0]) {
+                                /* the OST has not managed to create all the
+                                 * objects we asked for */
+                                oscc->oscc_grow_count = max(diff,
+                                                            OST_MIN_PRECREATE);
+                                /* don't bump grow_count next time */
+                                oscc->oscc_flags |= OSCC_FLAG_LOW;
+                        } else {
+                                /* the OST is able to keep up with the work,
+                                 * we could consider increasing grow_count
+                                 * next time if needed */
                                 oscc->oscc_flags &= ~OSCC_FLAG_LOW;
+                        }
                         oscc->oscc_last_id = body->oa.o_id;
                 }
                 spin_unlock(&oscc->oscc_lock);
@@ -184,6 +199,7 @@ static int oscc_internal_create(struct osc_creator *oscc)
         body->oa.o_id = oscc->oscc_last_id + oscc->oscc_grow_count;
         body->oa.o_gr = 0;
         body->oa.o_valid |= OBD_MD_FLID | OBD_MD_FLGROUP;
+        request->rq_async_args.space[0] = oscc->oscc_grow_count;
         spin_unlock(&oscc->oscc_lock);
         CDEBUG(D_RPCTRACE, "prealloc through id "LPU64" (last seen "LPU64")\n",
                body->oa.o_id, oscc->oscc_last_id);
-- 
1.8.3.1