Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752797AbYKFUdS (ORCPT ); Thu, 6 Nov 2008 15:33:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751007AbYKFUdD (ORCPT ); Thu, 6 Nov 2008 15:33:03 -0500 Received: from smtp-out.google.com ([216.239.45.13]:60219 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733AbYKFUdC (ORCPT ); Thu, 6 Nov 2008 15:33:02 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding; b=Wp/j70TlZo8SRCT/JKbhHx+epMg5RZXQWG68Hf+ZEoDX8HEXYnNdxgLhli1usGxgh hZ4dZSh0HqzCLqG5a0Oig== MIME-Version: 1.0 In-Reply-To: <20081106200746.GA3578@elte.hu> References: <20081106200746.GA3578@elte.hu> Date: Thu, 6 Nov 2008 12:32:55 -0800 Message-ID: Subject: Re: [patch] restore sched_exec load balance heuristics From: Ken Chen To: Ingo Molnar Cc: Linux Kernel Mailing List , Peter Zijlstra , Mike Galbraith Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1020 Lines: 21 On Thu, Nov 6, 2008 at 12:07 PM, Ingo Molnar wrote: > ok, this should be solved - but rather at the level of > sched_balance_self(): it should never migrate this task over to > another cpu, it should take away this task's load from the current > CPU's load when considering migration. There are two callers to sched_balance_self(). In the sched_fork path, sched_balance_self will balance the newly forked task. I think it is OK to bounce a newly forked task to another CPU since current CPU will be busy when fork returns in the parent process. And if sched_balance_self() needs to different between fork / exec load balance, it has to check a flag from function argument, which I think it is better to just short circuit in sched_exec() directly. - Ken -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/