From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754721AbYDBIlw (ORCPT ); Wed, 2 Apr 2008 04:41:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751886AbYDBIlp (ORCPT ); Wed, 2 Apr 2008 04:41:45 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:53700 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751785AbYDBIlo (ORCPT ); Wed, 2 Apr 2008 04:41:44 -0400 Message-ID: <47F346A8.5000801@jp.fujitsu.com> Date: Wed, 02 Apr 2008 17:41:12 +0900 From: Hidetoshi Seto User-Agent: Thunderbird 2.0.0.12 (Windows/20080213) MIME-Version: 1.0 To: Peter Zijlstra CC: linux-kernel@vger.kernel.org, Ingo Molnar , Paul Jackson Subject: Re: [PATCH 2/2] Customize sched domain via cpuset References: <47F21C38.8090608@jp.fujitsu.com> <1207050712.8514.715.camel@twins> In-Reply-To: <1207050712.8514.715.camel@twins> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra wrote: > On Tue, 2008-04-01 at 20:27 +0900, Hidetoshi Seto wrote: >> The implementation is here. >> >> - Add 2 new cpuset files: >> sched_wake_idle_far >> sched_balance_newidle_far >> >> - Modify partition_sched_domains() and build_sched_domains() >> to take flags parameter passed from cpuset. >> >> - Fill newidle_idx for node domains which currently unused but >> might be required for sched_balance_newidle_far. > > Just to be clear; the same effect can be had by poking into: > > /proc/sys/kernel/sched_domain/$cpu/$domain/flags > > but this interface you now propose gives a more stable interface in that > you'd have to re-do your setting after every cpuset change (admittedly > those are rare, but I see how it could be a nuisance). And the sysctl entry "sched_domain" is not available unless SCHED_DEBUG. So it is common sense that this sysctl is not open to public yet, and that the expected users are scheduler developers, Ingo and friends. > Or do you actually add something that wasn't available through the > initial domain interface? At this time I have no idea, but it would be possible if there are something unreasonable on global system but acceptable on a part. In other words, we can invent other sched_* families which has special effect that "default scheduler" never have. Thanks, H.Seto