From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933268Ab1INUXP (ORCPT ); Wed, 14 Sep 2011 16:23:15 -0400 Received: from mga09.intel.com ([134.134.136.24]:38298 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933142Ab1INUXO (ORCPT ); Wed, 14 Sep 2011 16:23:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="48481992" From: Andi Kleen To: Peter Zijlstra Cc: Glauber Costa , linux-kernel@vger.kernel.org, xemul@parallels.com, paul@paulmenage.org, lizf@cn.fujitsu.com, daniel.lezcano@free.fr, mingo@elte.hu, jbottomley@parallels.com Subject: Re: [PATCH 0/9] Per-cgroup /proc/stat References: <1316030695-19826-1-git-send-email-glommer@parallels.com> <1316031196.5040.46.camel@twins> Date: Wed, 14 Sep 2011 13:23:14 -0700 In-Reply-To: <1316031196.5040.46.camel@twins> (Peter Zijlstra's message of "Wed, 14 Sep 2011 22:13:16 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > > Guys we should seriously trim back a lot of that code, not grow ever > more and more. The sad fact is that if you build a kernel with > cpu-cgroup support the context switch cost is more than double that of a > kernel without, and then you haven't even started creating cgroups yet. That sounds indeed quite bad. Is it known why it is so costly? -Andi -- ak@linux.intel.com -- Speaking for myself only