From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752916Ab0JMTKQ (ORCPT ); Wed, 13 Oct 2010 15:10:16 -0400 Received: from smtp-out.google.com ([216.239.44.51]:34294 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752878Ab0JMTKN (ORCPT ); Wed, 13 Oct 2010 15:10:13 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=ktQUG28wAoxmvQ0qgckqqlo7cuw3X/xG7BMRif3dg8lrzd361hrImLz7f3S3Iev58 xfKU5A6jZ9Q+2hnYJKbQA== From: Nikhil Rao To: Ingo Molnar , Peter Zijlstra , Mike Galbraith , Suresh Siddha , Venkatesh Pallipadi Cc: linux-kernel@vger.kernel.org, Nikhil Rao Subject: [PATCH 1/4] sched: do not consider SCHED_IDLE tasks to be cache hot Date: Wed, 13 Oct 2010 12:09:35 -0700 Message-Id: <1286996978-7007-2-git-send-email-ncrao@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1286996978-7007-1-git-send-email-ncrao@google.com> References: <1286996978-7007-1-git-send-email-ncrao@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds a check in task_hot to return if the task has SCHED_IDLE policy. SCHED_IDLE tasks have very low weight, and when run with regular workloads, are typically scheduled many milliseconds apart. There is no need to consider these tasks hot for load balancing. Signed-off-by: Nikhil Rao --- kernel/sched.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index dc85ceb..6a9bdeb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2003,6 +2003,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) if (p->sched_class != &fair_sched_class) return 0; + if (p->policy == SCHED_IDLE) + return 0; + /* * Buddy candidates are cache hot: */ -- 1.7.1