Re: [PATCH V3 3/7] workqueue: Add helpers to schedule work on any cpu

From: Viresh Kumar
Date: Tue Mar 19 2013 - 01:15:41 EST


On 18 March 2013 20:53, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> queue_work() queues work on current cpu. This may wake up an idle CPU, which is
> actually not required.
>
> Some of these works can be processed by any CPU and so we must select a non-idle
> CPU here. The initial idea was to modify implementation of queue_work(), but
> that may end up breaking lots of kernel code that would be a nightmare to debug.
>
> So, we finalized to adding new workqueue interfaces, for works that don't depend
> on a cpu to execute them.

Fixup:

commit 6e5b6fac3353f5e4e5490931b3eb6d3fd7864ca0
Author: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Date: Tue Mar 19 10:34:20 2013 +0530

fixup! workqueue: Add helpers to schedule work on any cpu
---
kernel/workqueue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index cf9c570..68daf50 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1242,7 +1242,7 @@ retry:
if (!(wq->flags & WQ_UNBOUND)) {
if (cpu == WORK_CPU_UNBOUND) {
if (on_any_cpu)
- cpu = sched_select_cpu(0);
+ cpu = sched_select_non_idle_cpu(0);
else
cpu = raw_smp_processor_id();
}
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