From: Waiman Long <waiman.long@hpe.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, Yuyang Du <yuyang.du@intel.com>,
Paul Turner <pjt@google.com>, Ben Segall <bsegall@google.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [PATCH v2 2/3] sched/fair: Move hot load_avg into its own cacheline
Date: Fri, 04 Dec 2015 15:19:20 -0500 [thread overview]
Message-ID: <5661F548.1010506@hpe.com> (raw)
In-Reply-To: <1449194876.3240.9.camel@gmail.com>
On 12/03/2015 09:07 PM, Mike Galbraith wrote:
> On Thu, 2015-12-03 at 14:34 -0500, Waiman Long wrote:
>> On 12/02/2015 11:32 PM, Mike Galbraith wrote:
>>> Is that with the box booted skew_tick=1?
>> I haven't tried that kernel parameter. I will try it to see if it can
>> improve the situation. BTW, will there be other undesirable side effects
>> of using this other than the increased power consumption as said in the
>> kernel-parameters.txt file?
> Not that are known. I kinda doubt you'd notice the power, but you
> should see a notable performance boost. Who knows, with a big enough
> farm of busy big boxen, it may save power by needing fewer of them.
>
> -Mike
>
You are right. Use skew_tick=1 did improve performance and reduce the
overhead of clock tick processing rather significantly. I think it
should be the default for large SMP boxes. Thanks for the tip.
Cheers,
Longman
next prev parent reply other threads:[~2015-12-04 20:19 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-02 18:41 [PATCH v2 0/3] sched/fair: Reduce contention on tg's load_avg Waiman Long
2015-12-02 18:41 ` [PATCH v2 1/3] sched/fair: Avoid redundant idle_cpu() call in update_sg_lb_stats() Waiman Long
2015-12-02 18:41 ` [PATCH v2 2/3] sched/fair: Move hot load_avg into its own cacheline Waiman Long
2015-12-02 20:02 ` bsegall
2015-12-03 19:26 ` Waiman Long
2015-12-03 19:41 ` bsegall
2015-12-03 4:32 ` Mike Galbraith
2015-12-03 19:34 ` Waiman Long
2015-12-04 2:07 ` Mike Galbraith
2015-12-04 20:19 ` Waiman Long [this message]
2015-12-03 10:56 ` Peter Zijlstra
2015-12-03 19:38 ` Waiman Long
2015-12-03 11:12 ` Peter Zijlstra
2015-12-03 17:56 ` bsegall
2015-12-03 18:17 ` Peter Zijlstra
2015-12-03 18:23 ` bsegall
2015-12-03 19:56 ` Waiman Long
2015-12-03 20:03 ` Peter Zijlstra
2015-12-04 11:57 ` [tip:sched/core] sched/fair: Move the cache-hot 'load_avg' variable " tip-bot for Waiman Long
2015-12-02 18:41 ` [PATCH v2 3/3] sched/fair: Disable tg load_avg update for root_task_group Waiman Long
2015-12-02 19:55 ` bsegall
2015-12-04 11:58 ` [tip:sched/core] sched/fair: Disable the task group load_avg update for the root_task_group tip-bot for Waiman Long
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