From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753043AbXDUQfn (ORCPT ); Sat, 21 Apr 2007 12:35:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753049AbXDUQfn (ORCPT ); Sat, 21 Apr 2007 12:35:43 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:54606 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751627AbXDUQfm (ORCPT ); Sat, 21 Apr 2007 12:35:42 -0400 Date: Sat, 21 Apr 2007 09:34:07 -0700 (PDT) From: Linus Torvalds To: Willy Tarreau cc: Ingo Molnar , Con Kolivas , linux-kernel@vger.kernel.org, Andrew Morton , Nick Piggin , Mike Galbraith , Arjan van de Ven , Peter Williams , Thomas Gleixner , caglar@pardus.org.tr, Gene Heskett Subject: Re: [REPORT] cfs-v4 vs sd-0.44 In-Reply-To: <20070421161818.GC7840@1wt.eu> Message-ID: References: <20070420140457.GA14017@elte.hu> <20070421121235.GA2044@1wt.eu> <20070421154614.GA26169@elte.hu> <20070421161818.GC7840@1wt.eu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 21 Apr 2007, Willy Tarreau wrote: > > If you remember, with 50/50, I noticed some difficulties to fork many > processes. I think that during a fork(), the parent has a higher probability > of forking other processes than the child. So at least, we should use > something like 67/33 or 75/25 for parent/child. It would be even better to simply have the rule: - child gets almost no points at startup - but when a parent does a "waitpid()" call and blocks, it will spread out its points to the childred (the "vfork()" blocking is another case that is really the same). This is a very special kind of "priority inversion" logic: you give higher priority to the things you wait for. Not because of holding any locks, but simply because a blockign waitpid really is a damn big hint that "ok, the child now works for the parent". Linus