[PATCH] slow_work_thread() should do the exclusive wait

David Howells
2009-06-11T12:13:19Z

From: Oleg Nesterov <oleg@redhat.com>

slow_work_thread() sleeps on slow_work_thread_wq without WQ_FLAG_EXCLUSIVE,
this means that slow_work_enqueue()->__wake_up(nr_exclusive => 1) wakes up all
kslowd threads. This is not what we want, so we change slow_work_thread() to
use prepare_to_wait_exclusive() instead.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

kernel/slow-work.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/slow-work.c b/kernel/slow-work.c
index b28d191..521ed20 100644
--- a/kernel/slow-work.c
+++ b/kernel/slow-work.c
@@ -372,8 +372,8 @@ static int slow_work_thread(void *_data)
vsmax *= atomic_read(&slow_work_thread_count);
vsmax /= 100;

- prepare_to_wait(&slow_work_thread_wq, &wait,
- TASK_INTERRUPTIBLE);
+ prepare_to_wait_exclusive(&slow_work_thread_wq, &wait,
+ TASK_INTERRUPTIBLE);
if (!freezing(current) &&
!slow_work_threads_should_exit &&
!slow_work_available(vsmax) &&