From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764195AbXGFReR (ORCPT ); Fri, 6 Jul 2007 13:34:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762149AbXGFReH (ORCPT ); Fri, 6 Jul 2007 13:34:07 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:52229 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762129AbXGFReF (ORCPT ); Fri, 6 Jul 2007 13:34:05 -0400 Date: Fri, 6 Jul 2007 19:33:19 +0200 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Andrew Morton , Mike Galbraith , Arjan van de Ven , Thomas Gleixner , Dmitry Adamushko , Srivatsa Vaddagiri Subject: [patch] CFS scheduler, -v19 Message-ID: <20070706173319.GA2356@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org i'm pleased to announce release -v19 of the CFS scheduler patchset. The rolled-up CFS patch against today's -git kernel, v2.6.22-rc7, v2.6.22-rc6-mm1, v2.6.21.5 or v2.6.20.14 can be downloaded from the usual place: http://people.redhat.com/mingo/cfs-scheduler/ The biggest user-visible change in -v19 is reworked sleeper fairness: it's similar in behavior to -v18 but works more consistently across nice levels. Fork-happy workloads (like kernel builds) should behave better as well. There are also a handful of speedups: unsigned math, 32-bit speedups, O(1) task pickup, debloating and other micro-optimizations. Changes since -v18: - merged the group-scheduling CFS-core changes from Srivatsa Vaddagiri. This makes up for the bulk of the changes in -v19 but has no behavioral impact. The final group-fairness enabler patch is now a small and lean add-on patch to CFS. - fix the bloat noticed by Andrew. On 32-bit it's now this: text data bss dec hex filename 24362 3905 24 28291 6e83 sched.o-rc7 33015 2538 20 35573 8af5 sched.o-v18 25805 2426 20 28251 6e5b sched.o-v19 so it's a net win compared to vanilla. On 64-bit it's even better: text data bss dec hex filename 35732 40314 2168 78214 13186 sched.o.x64-rc7 41397 37642 2168 81207 13d37 sched.o.x64-v18 36132 37410 2168 75710 127be sched.o.x64-v19 ( and there's also a +1.5K data win per CPU on x32, which is not shown here. [+3.0K data win per CPU on x64.] ) - good number of core code updates, cleanups and streamlining. (Mike Galbraith, Srivatsa Vaddagiri, Dmitry Adamushko, me.) - use unsigned data types almost everywhere in CFS. This produces faster and smaller code, and simplifies the logic. - turn as many 'u64' data types into 'unsigned long' as possible, to reduce the 32-bit footprint and to reduce 64-bit arithmetics. - replaced the nr_running based 'sleep fairness' logic with a more robust concept. The end-result is similar in behavior to v18, but negative nice levels are handled much better in this scheme. - speedup: O(1) task pickup by Srivatsa Vaddagiri. [sleep/wakeup is O(log2(nr_running)).] This gives 5-10% better hackbench 100/500 results on a 4-way box. - fix: set idle->sched_class back to &idle_sched_class in migration_call(). (Dmitry Adamushko) - cleanup: use an enum for the sched_feature flags. (suggested by Andrew Morton) - cleanup: turn the priority macros into inlines. (suggested by Andrew Morton) - (other cleanups suggested by Andrew Morton) - debug: split out the debugging data into CONFIG_SCHED_DEBUG. As usual, any sort of feedback, bugreport, fix and suggestion is more than welcome! Ingo