path: root/mm/backing-dev.c
diff options
authorArtem Bityutskiy <>2010-07-25 14:29:14 +0300
committerJens Axboe <>2010-08-07 18:53:55 +0200
commitc4ec7908c2c5125f75fabd100e7a95626a6883ee (patch)
treed58ee401205de8385c74a04e9b66101fc9a6e22b /mm/backing-dev.c
parentc5f7ad233b8805dae06e694538d8095b19f3c560 (diff)
writeback: do not lose wake-ups in the forker thread - 2
Currently, if someone submits jobs for the default bdi, we can lose wake-up events. E.g., this can happen if 'bdi_queue_work()' is called when 'bdi_forker_thread()' is executing code after 'wb_do_writeback(me, 0)', but before 'set_current_state(TASK_INTERRUPTIBLE)'. This situation is unlikely, and the result is not very severe - we'll just delay the execution of the work, but this is still not very nice. This patch fixes the issue by checking whether the default bdi has works before the forker thread goes sleep. Signed-off-by: Artem Bityutskiy <> Reviewed-by: Christoph Hellwig <> Signed-off-by: Jens Axboe <>
Diffstat (limited to 'mm/backing-dev.c')
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index b1dc2d4b9cdd..72e6eb96efe2 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -358,6 +358,10 @@ static int bdi_forker_thread(void *ptr)
+ /* Keep working if default bdi still has things to do */
+ if (!list_empty(&me->bdi->work_list))
+ __set_current_state(TASK_RUNNING);
if (list_empty(&bdi_pending_list)) {
unsigned long wait;