From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752771AbZHYJr2 (ORCPT ); Tue, 25 Aug 2009 05:47:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751156AbZHYJr1 (ORCPT ); Tue, 25 Aug 2009 05:47:27 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:57520 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751027AbZHYJr1 (ORCPT ); Tue, 25 Aug 2009 05:47:27 -0400 Date: Tue, 25 Aug 2009 15:17:29 +0530 From: Bharata B Rao To: linux-kernel@vger.kernel.org Cc: Dhaval Giani , Balbir Singh , Vaidyanathan Srinivasan , Gautham R Shenoy , Srivatsa Vaddagiri , Ingo Molnar , Peter Zijlstra , Pavel Emelyanov , Herbert Poetzl , Avi Kivity , Chris Friesen , Paul Menage , Mike Waychison Subject: [RFC v1 PATCH 0/7] CFS Hard limits - v1 Message-ID: <20090825094729.GP3663@in.ibm.com> Reply-To: bharata@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, RFC on Hard limits feature for CFS group scheduler was posted earlier at http://lkml.org/lkml/2009/6/4/24. This is the next RFC post with patches. During the previous post, the need for hard limits feature was acknowledged. Also it was mentioned that guarantees would also be desirable. This post just addresses the limits part and there is no intention to address the guarantees problem with this patchset. This patchset has seen some very light testing and I believe that there will be bugs in it. However if you feel brave enough, this patchset could be tried on 2.6.31-rc7! Features TODO ------------- - Runtime borrowing isn't implemented yet, plan to add it in subsequent posts. - Bandwidth inheritence support (long term, not under consideration currently) - This implementation doesn't work for user group scheduler. Since user group scheduler will eventually go away, I don't plan to work on this. Implementation TODO ------------------- - This patchset has seen very minimal testing. I need to test this under more test scenarios. - I have been testing this on a 8 CPU box. Need to see how this behaves on a bigger box. - Need to run performance tests and regression tests for benchmarks on bigger machines. - It is possible to share some of the bandwidth handling code with RT, but the intention of this post is to show the changes associated with hard limits. Hence the sharing/cleanup will be done down the line when this patchset itself becomes more accepatable. - When a dequeued entity is enqueued back, I don't change its vruntime. The entity might get undue advantage due to its old (lower) vruntime. Need to address this. This set has the following patches: 1/7 sched: Rename sched_rt_period_mask() and use it in CFS also 2/7 sched: Maintain aggregated tasks count in cfs_rq at each hierarchy level 3/7 sched: Bandwidth initialization for fair task groups 4/7 sched: Enforce hard limits by throttling 5/7 sched: Unthrottle the throttled tasks 6/7 sched: Add throttle time statistics to /proc/sched_debug 7/7 sched: Hard limits documentation Documentation/scheduler/sched-cfs-hard-limits.txt | 52 +++ include/linux/sched.h | 7 init/Kconfig | 13 kernel/sched.c | 346 +++++++++++++++++++- kernel/sched_debug.c | 21 + kernel/sched_fair.c | 268 +++++++++++++++ kernel/sched_rt.c | 19 - 7 files changed, 703 insertions(+), 23 deletions(-) Regards, Bharata.