Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266867AbUIIX7k (ORCPT ); Thu, 9 Sep 2004 19:59:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266870AbUIIX7i (ORCPT ); Thu, 9 Sep 2004 19:59:38 -0400 Received: from holomorphy.com ([207.189.100.168]:40884 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S266867AbUIIX7Q (ORCPT ); Thu, 9 Sep 2004 19:59:16 -0400 Date: Thu, 9 Sep 2004 16:59:03 -0700 From: William Lee Irwin III To: Marcelo Tosatti Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] cacheline align pagevec structure Message-ID: <20040909235903.GQ3106@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Marcelo Tosatti , Andrew Morton , linux-kernel@vger.kernel.org References: <20040909163929.GA4484@logos.cnet> <20040909155226.714dc704.akpm@osdl.org> <20040909230905.GO3106@holomorphy.com> <20040909221238.GA6182@logos.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040909221238.GA6182@logos.cnet> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 23 On Thu, Sep 09, 2004 at 04:09:05PM -0700, William Lee Irwin III wrote: >> Reducing arrival rates by an Omega(NR_CPUS) factor would probably help, >> though that may blow the stack on e.g. larger Altixen. Perhaps >> O(lg(NR_CPUS)), e.g. NR_CPUS > 1 ? 4*lg(NR_CPUS) : 4 etc., will suffice, >> though we may have debates about how to evaluate lg(n) at compile-time... >> Would be nice if calls to sufficiently simple __attribute__((pure)) >> functions with constant args were considered constant expressions by gcc. On Thu, Sep 09, 2004 at 07:12:38PM -0300, Marcelo Tosatti wrote: > Let me see if I get you right - basically what you're suggesting is > to depend PAGEVEC_SIZE on NR_CPUS? Yes. The motive is that as the arrival rate is O(num_cpus_online()), and NR_CPUS is supposed to be strongly correlated with that, so reducing the arrival rate by a (hopefully) similar factor ought to help. -- wli - 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/