From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jisheng Zhang <jszhang@marvell.com>
Subject: RE: regression caused by bb6ab52f2bef ("intel_pstate: Do not set
 utilization update hook too early")
Date: Fri, 17 Jun 2016 15:53:40 +0000
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To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Viresh Kumar <viresh.kumar@linaro.org>, "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>

Dear Rafael,

I used intel_pstate.

I just tested v4.7-rc3, which should include commit 4578ee7e1def intel_=
pstate: Avoid
unnecessary synchronize_sched() during initialization, I can still get =
the same=20
wakeups, so it's not sufficient.

Another clue maybe helpful, I found these top2 wakeup/s is consistent, =
e.g
rcu_sched always gives about 10 wakeups/s, and tick_sched_timer gave
5.6-5.9 wakeups/s,=20

            144.3 =B5s/s      10.0        Process        [rcu_sched]

            193.9 =B5s/s       5.7        Timer          tick_sched_tim=
er

Thanks,
Jisheng

________________________________________
=46rom:  Rafael J. Wysocki=20
Sent: Friday, June 17, 2016 23:42
To: Jisheng Zhang
Cc: Peter Zijlstra; Paul E. McKenney; Rafael J. Wysocki; Viresh Kumar; =
linux-pm@vger.kernel.org; Linux Kernel Mailing List
Subject: Re: regression caused by bb6ab52f2bef ("intel_pstate: Do not s=
et utilization update hook too early")

On Fri, Jun 17, 2016 at 5:40 PM, Rafael J. Wysocki  wrote:
> On Fri, Jun 17, 2016 at 5:32 PM, Jisheng Zhang  wrote:
>> Hi all,
>>
>> First of all, sorry for top post, only webmail is available now.
>>
>> Second, sorry again for report incorrect commit, I were too tired th=
is morning so I remember the wrong commit.  The regression is caused by=
 bb6ab52f2bef ("intel_pstate: Do not set utilization update hook too ea=
rly"), so I update the email title.
>
> OK, that makes much more sense. :-)
>
> And
>
> 4578ee7e1def intel_pstate: Avoid unnecessary synchronize_sched()
> during initialization
>
> is not sufficient I suppose?

I mean, it is not sufficient to reduce the number of wakeups again?