From: Mike Galbraith <efault@gmx.de>
To: Robert Kubrick <robertkubrick@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: 2.6.32 / RH 6.1 scheduler bloated
Date: Sun, 09 Oct 2011 08:03:33 +0200 [thread overview]
Message-ID: <1318140213.6216.40.camel@marge.simson.net> (raw)
In-Reply-To: <35C27021-40FC-4127-BC82-9F86FA9D624A@gmail.com>
On Sat, 2011-10-08 at 20:26 -0400, Robert Kubrick wrote:
> A simple ftrace wakeup test shows 10us latency during the idle-to-run
> transition:
If you boot nohz=off idle=poll, and measure with cyclictest (measure in
userspace for free), you'll likely see a remarkable difference.
Coming out of idle can be slow, but that has more to do with silicon
than scheduler bloat (not that bloat doesn't exist mind you). My Q6600
box _sucks_ at getting off it's duff, even intel_idle.max_cstate=1 is
horrid. E5620 gets moving > order of magnitude more quickly with the
same kernel/config/params.
-Mike
next prev parent reply other threads:[~2011-10-09 6:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-09 0:26 Robert Kubrick
2011-10-09 6:03 ` Mike Galbraith [this message]
2011-10-09 14:26 ` Robert Kubrick
2011-10-09 17:38 ` Valdis.Kletnieks
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