From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756071Ab0CKScc (ORCPT ); Thu, 11 Mar 2010 13:32:32 -0500 Received: from hera.kernel.org ([140.211.167.34]:40869 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755379Ab0CKScU (ORCPT ); Thu, 11 Mar 2010 13:32:20 -0500 Date: Thu, 11 Mar 2010 18:31:45 GMT From: tip-bot for Mike Galbraith Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1268301285.6785.34.camel@marge.simson.net> References: <1268301285.6785.34.camel@marge.simson.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: Tweak sched_latency and min_granularity Message-ID: Git-Commit-ID: 21406928afe43f1db6acab4931bb8c886f4d04ce X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 11 Mar 2010 18:31:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 21406928afe43f1db6acab4931bb8c886f4d04ce Gitweb: http://git.kernel.org/tip/21406928afe43f1db6acab4931bb8c886f4d04ce Author: Mike Galbraith AuthorDate: Thu, 11 Mar 2010 17:17:15 +0100 Committer: Ingo Molnar CommitDate: Thu, 11 Mar 2010 18:32:51 +0100 sched: Tweak sched_latency and min_granularity Allow LAST_BUDDY to kick in sooner, improving cache utilization as soon as a second buddy pair arrives on scene. The cost is latency starting to climb sooner, the tbenefit for tbench 8 on my Q6600 box is ~2%. No detrimental effects noted in normal idesktop usage. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1268301285.6785.34.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 69e5820..d19df5b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -35,8 +35,8 @@ * (to see the precise effective timeslice length of your workload, * run vmstat and monitor the context-switches (cs) field) */ -unsigned int sysctl_sched_latency = 5000000ULL; -unsigned int normalized_sysctl_sched_latency = 5000000ULL; +unsigned int sysctl_sched_latency = 6000000ULL; +unsigned int normalized_sysctl_sched_latency = 6000000ULL; /* * The initial- and re-scaling of tunables is configurable @@ -52,15 +52,15 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling /* * Minimal preemption granularity for CPU-bound tasks: - * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity = 1000000ULL; -unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL; +unsigned int sysctl_sched_min_granularity = 2000000ULL; +unsigned int normalized_sysctl_sched_min_granularity = 2000000ULL; /* * is kept at sysctl_sched_latency / sysctl_sched_min_granularity */ -static unsigned int sched_nr_latency = 5; +static unsigned int sched_nr_latency = 3; /* * After fork, child runs first. If set to 0 (default) then