From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964895AbWGEOnJ (ORCPT ); Wed, 5 Jul 2006 10:43:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964896AbWGEOnJ (ORCPT ); Wed, 5 Jul 2006 10:43:09 -0400 Received: from mail.gmx.de ([213.165.64.21]:36528 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S964895AbWGEOnI (ORCPT ); Wed, 5 Jul 2006 10:43:08 -0400 X-Authenticated: #14349625 Subject: Re: [PATCH] sched: Add SCHED_BGND (background) scheduling policy From: Mike Galbraith To: Peter Williams Cc: Andrew Morton , Nick Piggin , Linux Kernel , Con Kolivas , Ingo Molnar In-Reply-To: <44ABC5B7.2090707@bigpond.net.au> References: <20060704233521.8744.45368.sendpatchset@heathwren.pw.nest> <1152099752.8684.198.camel@Homer.TheSimpsons.net> <44ABC5B7.2090707@bigpond.net.au> Content-Type: text/plain Date: Wed, 05 Jul 2006 16:48:27 +0200 Message-Id: <1152110907.8594.19.camel@Homer.TheSimpsons.net> Mime-Version: 1.0 X-Mailer: Evolution 2.4.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-07-05 at 23:59 +1000, Peter Williams wrote: > Mike Galbraith wrote: > > The task in the expired array could also be a !safe_to_background() task > > who already had a chance to run, and who's slice expired. > > If it's !safe_to_background() it's in our interest to let it run in > order to free up the resource that it's holding. Only if there are waiters (or you know there will be some before the holder gets a chance to run again). Even then, they might be background tasks, so it could still be ~wrong. (yeah, comprehensive PI would be mucho tidier than tick time) -Mike