linux-kernel - Re: sched: Avoid SMT siblings in select_idle

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

Message-ID: <1329996064.7411.106.camel@marge.simpson.net>
Date:	Thu, 23 Feb 2012 12:21:04 +0100
From:	Mike Galbraith <efault@....de>
To:	Srivatsa Vaddagiri <vatsa@...ux.vnet.ibm.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...e.hu>, Paul Turner <pjt@...gle.com>
Subject: Re: sched: Avoid SMT siblings in select_idle_sibling() if possible

On Thu, 2012-02-23 at 16:19 +0530, Srivatsa Vaddagiri wrote:

> I am seeing 2.6% _improvement_ in volanomark score by enabling SD_BALANCE_WAKE 
> at SMT/MC domains.

That's an unexpected (but welcome) result.

> Machine : 2 Quad-core Intel X5570 CPU (H/T enabled)
> Kernel  : tip (HEAD at 6241cc8)
> Java	: OpenJDK 1.6.0_20
> Volano  : 2_9_0
> 
> Volano benchmark was run 4 times with and w/o SD_BALANCE_WAKE enabled in
> SMT/MC domains.
> 
> 				Average score	std. dev
> 
> SD_BALANCE_WAKE disabled	369459.750	4825.046
> SD_BALANCE_WAKE enabled		379070.500	379070.5
> 
> I am going to try pipe benchmark next. Do you have suggestions for any other 
> benchmarks I should try to see the effect of SD_BALANCE_WAKE turned on in 
> SMT/MC domains?

Unpinned netperf TCP_RR and/or tbench pairs?  Anything that's wakeup
heavy should tell the tail.

-Mike

--
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/