From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756750AbYFKI4V (ORCPT ); Wed, 11 Jun 2008 04:56:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753393AbYFKI4N (ORCPT ); Wed, 11 Jun 2008 04:56:13 -0400 Received: from viefep32-int.chello.at ([62.179.121.50]:47703 "EHLO viefep32-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751667AbYFKI4M (ORCPT ); Wed, 11 Jun 2008 04:56:12 -0400 Subject: Re: [sched-devel, patch-rfc] rework of "prioritize non-migratable tasks over migratable ones" From: Peter Zijlstra To: Dmitry Adamushko Cc: Gregory Haskins , Steven Rostedt , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org In-Reply-To: <1213138710.26530.51.camel@earth> References: <1213138710.26530.51.camel@earth> Content-Type: text/plain Date: Wed, 11 Jun 2008 10:53:02 +0200 Message-Id: <1213174382.31518.69.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2008-06-11 at 00:58 +0200, Dmitry Adamushko wrote: > Hi Gregory, > > > regarding this commit: 45c01e824991b2dd0a332e19efc4901acb31209f > > > I think we can do it simpler. Please take a look at the patch below. > > Instead of having 2 separate arrays (which is + ~800 bytes on x86_32 and twice so on x86_64), > let's add "exclusive" (the ones that are bound to this CPU) tasks to the head of the queue > and "shared" ones -- to the end. > > In case of a few newly woken up "exclusive" tasks, they are 'stacked' (not queued as now), meaning that > a task {i+1} is being placed in front of the previously woken up task {i}. But I don't think that > this behavior may cause any realistic problems. Doesn't this violate POSIX ?