linux-kernel - Re: [RFC PATCH 00/13] sched: Integrating Per-entity-load-tracking with the core scheduler

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]

Message-ID: <508B56A7.1010501@linux.vnet.ibm.com>
Date:	Sat, 27 Oct 2012 09:06:07 +0530
From:	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
To:	Ingo Molnar <mingo@...nel.org>
CC:	Peter Zijlstra <a.p.zijlstra@...llo.nl>, svaidy@...ux.vnet.ibm.com,
	linux-kernel@...r.kernel.org, venki@...gle.com,
	robin.randhawa@....com, linaro-dev@...ts.linaro.org,
	mjg59@...f.ucam.org, viresh.kumar@...aro.org,
	akpm@...ux-foundation.org, amit.kucheria@...aro.org,
	deepthi@...ux.vnet.ibm.com, paul.mckenney@...aro.org,
	arjan@...ux.intel.com, paulmck@...ux.vnet.ibm.com,
	srivatsa.bhat@...ux.vnet.ibm.com, vincent.guittot@...aro.org,
	tglx@...utronix.de, Arvind.Chauhan@....com, pjt@...gle.com,
	Morten.Rasmussen@....com, linux-arm-kernel@...ts.infradead.org,
	suresh.b.siddha@...el.com
Subject: Re: [RFC PATCH 00/13] sched: Integrating Per-entity-load-tracking
 with the core scheduler

On 10/26/2012 06:37 PM, Ingo Molnar wrote:
> 
> * Peter Zijlstra <a.p.zijlstra@...llo.nl> wrote:
> 
>> [...]
>>
>> So a sane series would introduce maybe two functions: 
>> cpu_load() and task_load() and use those where we now use 
>> rq->load.weight and p->se.load.weight for load balancing 
>> purposes. Implement these functions using those two 
>> expression. So effectively this patch is a NOP.
>>
>> Secondly, switch these two functions over to the per-task 
>> based averages.
>>
>> Tada! all done. The load balancer will then try and equalize 
>> effective load instead of instant load.
>>
>> It will do the 3x10% vs 100% thing correctly with just those 
>> two patches. Simply because it will report a lower cpu-load 
>> for the 3x10% case than it will for the 100% case, no need to 
>> go fudge about in the load-balance internals.
>>
>> Once you've got this correctly done, you can go change 
>> balancing to better utilize the new metric, like use the 
>> effective load instead of nr_running against the capacity and 
>> things like that. But for every such change you want to be 
>> very careful and run all the benchmarks you can find -- in 
>> fact you want to do that after the 2nd patch too.
> 
> If anyone posted that simple two-patch series that switches over 
> to the new load metrics I'd be happy to test the performance of 
> those.
> 
> Having two parallel load metrics is really not something that we 
> should tolerate for too long.
> 
> Thanks,
> 
> 	Ingo
> 
Right Ingo.I will incorporate this approach and post out very soon.

Thank you

Regards
Preeti

--
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/