From d5956937297fa50c1b989587b5825cf69c4560cb Mon Sep 17 00:00:00 2001
From: johann <johann>
Date: Thu, 10 Dec 2009 22:31:04 +0000
Subject: [PATCH] Branch b1_8 b=19557 i=adilger i=andrew

add cond_resched() calls to lustre_hash_for_each_empty() to avoid hogging
the cpu when many locks to process on disconnect/eviction.
---
 lustre/ChangeLog             | 7 +++++++
 lustre/obdclass/class_hash.c | 1 +
 lustre/obdclass/genops.c     | 2 +-
 lustre/ptlrpc/service.c      | 2 +-
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/lustre/ChangeLog b/lustre/ChangeLog
index 5e213cd..6f6e4ae 100644
--- a/lustre/ChangeLog
+++ b/lustre/ChangeLog
@@ -242,6 +242,13 @@ Description: bad entry in directory xxx: inode out of bounds
 Details    : fix locking issue in the rename path which could race with any
 	     other operations updating the same directory.
 
+Severity   : normal
+Bugzilla   : 19557
+Description: BUG: soft lockup - CPU#1 stuck for 10s! [ll_mdt_07:4523]
+Details    : add cond_resched() calls to avoid hogging the cpu for too long
+	     in the hash code.
+
+
 -------------------------------------------------------------------------------
 2009-10-16 Sun Microsystems, Inc.
 	* version 1.8.1.1
diff --git a/lustre/obdclass/class_hash.c b/lustre/obdclass/class_hash.c
index 762aebf..2e51f27 100644
--- a/lustre/obdclass/class_hash.c
+++ b/lustre/obdclass/class_hash.c
@@ -524,6 +524,7 @@ restart:
                         lh_read_unlock(lh);
                         func(obj, data);
                         (void)lh_put(lh, hnode);
+                        cfs_cond_resched();
                         goto restart;
                 }
                 write_unlock(&lhb->lhb_rwlock);
diff --git a/lustre/obdclass/genops.c b/lustre/obdclass/genops.c
index 3136e66..743746e 100644
--- a/lustre/obdclass/genops.c
+++ b/lustre/obdclass/genops.c
@@ -1472,7 +1472,7 @@ void obd_zombie_impexp_cull(void)
 
                 if (export != NULL)
                         class_export_destroy(export);
-
+                cfs_cond_resched();
         } while (import != NULL || export != NULL);
 }
 
diff --git a/lustre/ptlrpc/service.c b/lustre/ptlrpc/service.c
index 5714aad..0a0fb2a 100644
--- a/lustre/ptlrpc/service.c
+++ b/lustre/ptlrpc/service.c
@@ -1650,7 +1650,7 @@ static int ptlrpc_main(void *arg)
 
                 lc_watchdog_disable(thread->t_watchdog);
 
-                cond_resched();
+                cfs_cond_resched();
 
                 l_wait_event_exclusive (svc->srv_waitq,
                               ((thread->t_flags & SVC_STOPPING) != 0 &&
-- 
1.8.3.1