From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751435Ab1JIGDi (ORCPT ); Sun, 9 Oct 2011 02:03:38 -0400 Received: from mailout-de.gmx.net ([213.165.64.23]:42967 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751213Ab1JIGDh (ORCPT ); Sun, 9 Oct 2011 02:03:37 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18TDYgQDUMTyXmw+fgEqXa330JNsyUcZQSCmjRw9+ CRC8XhbR5UGy3j Subject: Re: 2.6.32 / RH 6.1 scheduler bloated From: Mike Galbraith To: Robert Kubrick Cc: linux-kernel@vger.kernel.org In-Reply-To: <35C27021-40FC-4127-BC82-9F86FA9D624A@gmail.com> References: <35C27021-40FC-4127-BC82-9F86FA9D624A@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Sun, 09 Oct 2011 08:03:33 +0200 Message-ID: <1318140213.6216.40.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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