LU-56 lnet: eliminate a few locking dance in LNet

[fs/lustre-release.git] / lnet / lnet / router.c

diff --git a/lnet/lnet/router.c b/lnet/lnet/router.c
index 08bb57c..86d24ad 100644 (file)
--- a/lnet/lnet/router.c
+++ b/lnet/lnet/router.c
@@ -736,40 +736,35 @@ lnet_wait_known_routerstate(void)
 }
 
 void
-lnet_update_ni_status(void)
+lnet_update_ni_status_locked(void)
 {
-        cfs_time_t now = cfs_time_current();
-        lnet_ni_t *ni;
-        int        status;
-        int        timeout;
-
-        LASSERT (the_lnet.ln_routing);
+       lnet_ni_t       *ni;
+       long            now;
+       int             timeout;
 
-        timeout = router_ping_timeout +
-                  MAX(live_router_check_interval, dead_router_check_interval);
+       LASSERT(the_lnet.ln_routing);
 
-        LNET_LOCK();
+       timeout = router_ping_timeout +
+                 MAX(live_router_check_interval, dead_router_check_interval);
 
-        cfs_list_for_each_entry (ni, &the_lnet.ln_nis, ni_list) {
-                lnet_ni_status_t *ns = ni->ni_status;
+       now = cfs_time_current_sec();
+       cfs_list_for_each_entry(ni, &the_lnet.ln_nis, ni_list) {
+               if (ni->ni_lnd->lnd_type == LOLND)
+                       continue;
 
-                LASSERT (ns != NULL);
+               if (now < ni->ni_last_alive + timeout)
+                       continue;
 
-                status = LNET_NI_STATUS_UP;
-                if (ni->ni_lnd->lnd_type != LOLND &&  /* @lo forever alive */
-                    cfs_time_after(now, cfs_time_add(ni->ni_last_alive,
-                                                     cfs_time_seconds(timeout))))
-                        status = LNET_NI_STATUS_DOWN;
+               LASSERT(ni->ni_status != NULL);
 
-                if (ns->ns_status != status) {
-                        ns->ns_status = status;
-                        CDEBUG(D_NET, "NI(%s:%d) status changed to %s\n",
-                               libcfs_nid2str(ni->ni_nid), timeout,
-                               status == LNET_NI_STATUS_UP ? "up" : "down");
-                }
-        }
-
-        LNET_UNLOCK();
+               if (ni->ni_status->ns_status != LNET_NI_STATUS_DOWN) {
+                       CDEBUG(D_NET, "NI(%s:%d) status changed to down\n",
+                              libcfs_nid2str(ni->ni_nid), timeout);
+                       /* NB: so far, this is the only place to set
+                        * NI status to "down" */
+                       ni->ni_status->ns_status = LNET_NI_STATUS_DOWN;
+               }
+       }
 }
 
 void
@@ -1196,10 +1191,10 @@ rescan:
                         }
                 }
 
-                LNET_UNLOCK();
+               if (the_lnet.ln_routing)
+                       lnet_update_ni_status_locked();
 
-                if (the_lnet.ln_routing)
-                        lnet_update_ni_status();
+               LNET_UNLOCK();
 
                lnet_prune_rc_data(0); /* don't wait for UNLINK */