Re: [PATCH] workqueue: Add basic tracepoints to track workqueueexecution

From: Frederic Weisbecker
Date: Sun Aug 22 2010 - 00:01:30 EST


On Sat, Aug 21, 2010 at 01:14:02PM -0700, Arjan van de Ven wrote:
>
> From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> Date: Sat, 21 Aug 2010 13:07:26 -0700
> Subject: [PATCH] workqueue: Add basic tracepoints to track workqueue execution
>
> With the introduction of the new unified work queue thread pools,
> we lost one feature: It's no longer possible to know which worker
> is causing the CPU to wake out of idle. The result is that PowerTOP
> now reports a lot of "kworker/a:b" instead of more readable results.
>
> This patch adds a pair of tracepoints to the new workqueue code,
> similar in style to the timer/hrtimer tracepoints.
>
> With this pair of tracepoints, the next PowerTOP can correctly
> report which work item caused the wakeup (and how long it took):
>
> Interrupt (43) i915 time 3.51ms wakeups 141
> Work ieee80211_iface_work time 0.81ms wakeups 29
> Work do_dbs_timer time 0.55ms wakeups 24
> Process Xorg time 21.36ms wakeups 4
> Timer sched_rt_period_timer time 0.01ms wakeups 1
>
> Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>



Ok, Linus applied it. That answers my doubts about the
route for this patch :)

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