linux-kernel - Re: [PATCH v2 2/3] sched/fair: Move hot load

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Fri, 04 Dec 2015 15:19:20 -0500
From:	Waiman Long <waiman.long@....com>
To:	Mike Galbraith <umgwanakikbuti@...il.com>
CC:	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel@...r.kernel.org, Yuyang Du <yuyang.du@...el.com>,
	Paul Turner <pjt@...gle.com>, Ben Segall <bsegall@...gle.com>,
	Morten Rasmussen <morten.rasmussen@....com>,
	Scott J Norton <scott.norton@....com>,
	Douglas Hatch <doug.hatch@....com>
Subject: Re: [PATCH v2 2/3] sched/fair: Move hot load_avg into its own cacheline

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/