summaryrefslogtreecommitdiffstats
path: root/kernel/workqueue.c
diff options
context:
space:
mode:
authorJoonsoo Kim <js1304@gmail.com>2012-08-15 23:25:38 +0900
committerTejun Heo <tj@kernel.org>2012-08-16 14:21:15 -0700
commite42986de481238204f6e0b0f4434da428895c20b (patch)
tree613150adf76500507ca69d59d5448fa05affbc98 /kernel/workqueue.c
parentb75cac9368fa91636e17d0f7950b35d837154e14 (diff)
downloadop-kernel-dev-e42986de481238204f6e0b0f4434da428895c20b.zip
op-kernel-dev-e42986de481238204f6e0b0f4434da428895c20b.tar.gz
workqueue: change value of lcpu in __queue_delayed_work_on()
We assign cpu id into work struct's data field in __queue_delayed_work_on(). In current implementation, when work is come in first time, current running cpu id is assigned. If we do __queue_delayed_work_on() with CPU A on CPU B, __queue_work() invoked in delayed_work_timer_fn() go into the following sub-optimal path in case of WQ_NON_REENTRANT. gcwq = get_gcwq(cpu); if (wq->flags & WQ_NON_REENTRANT && (last_gcwq = get_work_gcwq(work)) && last_gcwq != gcwq) { Change lcpu to @cpu and rechange lcpu to local cpu if lcpu is WORK_CPU_UNBOUND. It is sufficient to prevent to go into sub-optimal path. tj: Slightly rephrased the comment. Signed-off-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c29f2dc..99ee9b9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1356,9 +1356,15 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
if (!(wq->flags & WQ_UNBOUND)) {
struct global_cwq *gcwq = get_work_gcwq(work);
- if (gcwq && gcwq->cpu != WORK_CPU_UNBOUND)
+ /*
+ * If we cannot get the last gcwq from @work directly,
+ * select the last CPU such that it avoids unnecessarily
+ * triggering non-reentrancy check in __queue_work().
+ */
+ lcpu = cpu;
+ if (gcwq)
lcpu = gcwq->cpu;
- else
+ if (lcpu == WORK_CPU_UNBOUND)
lcpu = raw_smp_processor_id();
} else {
lcpu = WORK_CPU_UNBOUND;
OpenPOWER on IntegriCloud