linux-kernel - Re: [PATCH v2] cpuidle: Fix the menu governor to boost IO performance

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]

Date:	Sun, 8 Nov 2009 14:39:08 -0800
From:	Arjan van de Ven <arjan@...radead.org>
To:	Corrado Zoccolo <czoccolo@...il.com>
Cc:	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>, lenb@...nel.org,
	mingo@...e.hu, yanmin_zhang@...ux.intel.com, jens.axboe@...cle.com,
	Ivan Kokshaysky <ink@...assic.park.msu.ru>
Subject: Re: [PATCH v2] cpuidle: Fix the menu governor to boost IO
 performance

On Sun, 8 Nov 2009 22:59:43 +0100
Corrado Zoccolo <czoccolo@...il.com> wrote:

> Unfortunately, I have seen polling residency times > 1ms, so it must
> not be so accurate.


hmm I wonder if the timer hardware in use has a much larger
granularity than usecs... 
because that rounding up could cost us dearly.

wonder if we should do some form of "check for timer expiry" as part of
the polling loop.. that'd cut latency way down as well ;)

-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
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/