From 0c79c62021d23f0b5c942cf59d43a7ce6c24cd1b Mon Sep 17 00:00:00 2001
From: Josef Bacik <jbacik@fb.com>
Date: Fri, 28 Jul 2017 10:42:24 -0400
Subject: [PATCH] dm log writes: don't use all the cpu while waiting to log
blocks
Git-commit: 0c79c62021d23f0b5c942cf59d43a7ce6c24cd1b
Patch-mainline: v4.14-rc1
References: bsc#1093023
The check to see if the logging kthread needs to go to sleep is wrong,
it checks lc->pending_blocks, which will be non-0 if there are any
blocks that are pending, whether they are ready to be logged or not.
What we really want is to go to sleep until it's time to log blocks, so
change this check so we do actually go to sleep in between flushes.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-log-writes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index a1da0eb58a93..9aab510a1709 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -399,7 +399,7 @@ static int log_writes_kthread(void *arg)
if (!try_to_freeze()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!kthread_should_stop() &&
- !atomic_read(&lc->pending_blocks))
+ list_empty(&lc->logging_blocks))
schedule();
__set_current_state(TASK_RUNNING);
}
--
2.16.3