From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760355Ab0I1AaY (ORCPT ); Mon, 27 Sep 2010 20:30:24 -0400 Received: from smtp-out.google.com ([74.125.121.35]:63250 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757891Ab0I1AaV (ORCPT ); Mon, 27 Sep 2010 20:30:21 -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=BboorWmt2lXW5t56L0EIMkOxYlg6sMp80rvZTlooBmDiI5VHOLPpzW5XsX1o8JIjh 7JtfbyZrEEOjWHItCWufA== From: Nikhil Rao To: Ingo Molnar , Peter Zijlstra , Mike Galbraith Cc: Venkatesh Pallipadi , linux-kernel@vger.kernel.org, Nikhil Rao Subject: [PATCH 3/3] sched: do not consider SCHED_IDLE tasks to be cache hot Date: Mon, 27 Sep 2010 17:29:58 -0700 Message-Id: <1285633798-26886-4-git-send-email-ncrao@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1285633798-26886-1-git-send-email-ncrao@google.com> References: <1285633798-26886-1-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 weight tasks, are typically scheduled many milliseconds apart. There is no benefit from considering SCHED_IDLE tasks cache 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 ed09d4f..874efde 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