linux-kernel - Re: [tip:x86/urgent] x86 idle: Repair large-server 50-watt idle-power regression

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: <1397532444.4223.1.camel@buesod1.americas.hpqcorp.net>
Date:	Mon, 14 Apr 2014 20:27:24 -0700
From:	Davidlohr Bueso <davidlohr@...com>
To:	"Brown, Len" <len.brown@...el.com>
Cc:	"mingo@...nel.org" <mingo@...nel.org>,
	"hpa@...or.com" <hpa@...or.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"hpa@...ux.intel.com" <hpa@...ux.intel.com>,
	Peter Zijlstra <peterz@...radead.org>,
	"linux-tip-commits@...r.kernel.org" 
	<linux-tip-commits@...r.kernel.org>
Subject: Re: [tip:x86/urgent] x86 idle: Repair large-server 50-watt
 idle-power regression

On Tue, 2014-04-08 at 21:43 +0000, Brown, Len wrote:
> Davidlohr,
> 
> Thanks for the note.
> 
> Ideally (on Linux in general, and on servers, in particular) we strive
> for the performance impact of power saving features to be small enough
> to be considered in "measurement noise".
> 
> Your report for 160 core Westmere AIM numbers being hit at 10-25%
> shows 15% measurement noise?  But even if true, this looks bad.
> 
> Any chance you can re-run, with the following two tweaks,
> one at a time?
> 
> I'd be curious if you can wrap the invocation in turbostat -v
> and capture that output to how what states we are seeing
> during the benchmark run.

Hi Len, apologies for the delay, I've been having to use my machine for
other things and haven't gotten time to get around to this yet. I'll get
you the requested information sometime this week.

--
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/