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

[Frederic Weisbecker <fweisbec@gmail.com>]

On Sat, Aug 21, 2010 at 01:14:02PM -0700, Arjan van de Ven wrote:
> 
> From: Arjan van de Ven <arjan@linux.intel.com>
> 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@linux.intel.com>



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