Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752476AbXA1T3F (ORCPT ); Sun, 28 Jan 2007 14:29:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932772AbXA1T3F (ORCPT ); Sun, 28 Jan 2007 14:29:05 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:42795 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752476AbXA1T3E (ORCPT ); Sun, 28 Jan 2007 14:29:04 -0500 Date: Sun, 28 Jan 2007 20:26:34 +0100 From: Ingo Molnar To: Bill Huey Cc: "Martin J. Bligh" , Christoph Hellwig , Peter Zijlstra , Andrew Morton , linux-kernel@vger.kernel.org, Dipankar Sarma Subject: Re: lockmeter Message-ID: <20070128192634.GA25370@elte.hu> References: <20070128115118.837777000@programming.kicks-ass.net> <20070128144325.GB16552@infradead.org> <20070128152404.GB9196@elte.hu> <45BCD4C9.2030302@mbligh.org> <20070128170407.GA1526@infradead.org> <45BCDF88.2020504@mbligh.org> <20070128180132.GA1647@gnuppy.monkey.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070128180132.GA1647@gnuppy.monkey.org> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -4.3 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-4.3 required=5.9 tests=ALL_TRUSTED,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 860 Lines: 23 * Bill Huey wrote: > > ISTR we still thought dcache scalability was a significant problem > > last time anyone looked at it seriously - just never got fixed. > > Dipankar? > > My lock stat stuff shows dcache to a be a problem under -rt as well. > [...] yeah, it shows up frequently, but it's hard to fix. for a well-cached kernel rebuild on a system with lots of RAM and lots of CPUs, files_lock is the leading lock. (because the dcache is mostly populated already) files_lock is even more of a problem for workloads that do lots of open()/close() [Apache comes to mind]. Ingo - 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/