From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755589AbZLWKOb (ORCPT ); Wed, 23 Dec 2009 05:14:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754630AbZLWKO3 (ORCPT ); Wed, 23 Dec 2009 05:14:29 -0500 Received: from mail-pw0-f42.google.com ([209.85.160.42]:56157 "EHLO mail-pw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754625AbZLWKO3 (ORCPT ); Wed, 23 Dec 2009 05:14:29 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:cc:content-type; b=FASFp6BlQS3y92Zft72y5Fd8OEwtxvIFAnJvFd+x0oi52Z8KK8oEctm6hFDUKKosf/ QbgfuuDv0bQHUlF7U1hJ1uJVJcIJdmHHYV1ut7RRWXNVG/YjRLyVWHjMSJNflkJXutvO eJs6uPvL1cP/m/j2EUfzgcnn/HtMyyVNIlhDw= MIME-Version: 1.0 Date: Wed, 23 Dec 2009 16:14:27 +0600 Message-ID: Subject: SCHED: Is task migration necessary in sched_exec(). From: Rakib Mullick To: Ingo Molnar , Peter Zijlstra Cc: LKML Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Is task migration necessary in sched_exec()? In sched_exec function's comment it says: "sched_exec - execve() is a valuable balancing opportunity, because at this point the task has the smallest effective memory and cache footprint." Right, but - when a execve() is called then this task will start execution (that means this task will not waiting on the runqueue as TASK_RUNNING/WAKING, it will get the CPU). At this point - what is the necessity to try making it balance. By looking at point of "smallest effective memory and cache footprint" , we are missing the point that we are unnecessarily pushing task when its about to execute. Isn't it? Or I'm missing anything? Rakib,