From: Liang Zhen <liang.zhen@intel.com>
Date: Wed, 16 Sep 2015 17:50:07 +0000 (+0800)
Subject: LU-7054 o2iblnd: less intense allocating retry
X-Git-Tag: 2.7.66~13
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=d96879f34ce229695566a3e5de1f5160f4c9ef02

LU-7054 o2iblnd: less intense allocating retry

ko2iblnd may retry too frequent for growing pools, all schedulers
are spinning if another thread is in progress of allocating a new
pool and can't finish right away because of high system load.

Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Change-Id: I21be43c6f77b1ae13d500ecbd6795b6d0099d2f1
Reviewed-on: http://review.whamcloud.com/16470
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lnet/klnds/o2iblnd/o2iblnd.c b/lnet/klnds/o2iblnd/o2iblnd.c
index 293bb0c..d9761ee 100644
--- a/lnet/klnds/o2iblnd/o2iblnd.c
+++ b/lnet/klnds/o2iblnd/o2iblnd.c
@@ -1306,6 +1306,7 @@ kiblnd_current_hdev(kib_dev_t *dev)
 		if (i++ % 50 == 0)
 			CDEBUG(D_NET, "%s: Wait for failover\n",
 			       dev->ibd_ifname);
+		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(cfs_time_seconds(1) / 100);
 
 		read_lock_irqsave(&kiblnd_data.kib_global_lock, flags);
@@ -1793,6 +1794,9 @@ kiblnd_pool_alloc_node(kib_poolset_t *ps)
 	struct list_head	*node;
 	kib_pool_t		*pool;
 	int			rc;
+	unsigned int		interval = 1;
+	cfs_time_t		time_before;
+	unsigned int		trips = 0;
 
 again:
 	spin_lock(&ps->ps_lock);
@@ -1817,10 +1821,17 @@ again:
 	if (ps->ps_increasing) {
 		/* another thread is allocating a new pool */
 		spin_unlock(&ps->ps_lock);
+		trips++;
                 CDEBUG(D_NET, "Another thread is allocating new "
-                       "%s pool, waiting for her to complete\n",
-                       ps->ps_name);
-		schedule();
+		       "%s pool, waiting %d HZs for her to complete."
+		       "trips = %d\n",
+		       ps->ps_name, interval, trips);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(interval);
+		if (interval < cfs_time_seconds(1))
+			interval *= 2;
+
                 goto again;
         }
 
@@ -1834,8 +1845,10 @@ again:
 	spin_unlock(&ps->ps_lock);
 
 	CDEBUG(D_NET, "%s pool exhausted, allocate new pool\n", ps->ps_name);
-
+	time_before = cfs_time_current();
 	rc = ps->ps_pool_create(ps, ps->ps_pool_size, &pool);
+	CDEBUG(D_NET, "ps_pool_create took %lu HZ to complete",
+	       cfs_time_current() - time_before);
 
 	spin_lock(&ps->ps_lock);
 	ps->ps_increasing = 0;