Workqueues queues work on current cpu, if the caller haven't passed a preferred cpu. This may wake up an idle CPU, which is actually not required.
This work can be processed by any CPU and so we must select a non-idle CPU here. This patch adds in support in workqueue framework to get preferred CPU details from the scheduler, instead of using current CPU. Most of the time when a work is queued, the current cpu isn't idle and so we will choose it only. There are cases when a cpu is idle when it queues some work. For example, consider following scenario: - A cpu has programmed a timer and is IDLE now. - CPU gets into interrupt handler due to timer and queues a work. As the CPU is currently IDLE, we can queue this work to some other CPU. Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org> --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 143fd8c..5fa4ba4 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1238,7 +1238,7 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq, struct global_cwq *last_gcwq; if (cpu == WORK_CPU_UNBOUND) - cpu = raw_smp_processor_id(); + cpu = sched_select_cpu(0); /* * It's multi cpu. If @work was previously on a different -- 1.7.12.rc2.18.g61b472e _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev