Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754361AbYAAMxo (ORCPT ); Tue, 1 Jan 2008 07:53:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753321AbYAAMxe (ORCPT ); Tue, 1 Jan 2008 07:53:34 -0500 Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:38629 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753252AbYAAMxd (ORCPT ); Tue, 1 Jan 2008 07:53:33 -0500 Date: Tue, 1 Jan 2008 07:47:41 -0500 From: Theodore Tso To: Andi Kleen Cc: Christoph Lameter , Willy Tarreau , Steven Rostedt , Linus Torvalds , Ingo Molnar , Peter Zijlstra , LKML , Andrew Morton , Christoph Hellwig , "Rafael J. Wysocki" Subject: Re: Major regression on hackbench with SLUB (more numbers) Message-ID: <20080101124741.GH11776@mit.edu> Mail-Followup-To: Theodore Tso , Andi Kleen , Christoph Lameter , Willy Tarreau , Steven Rostedt , Linus Torvalds , Ingo Molnar , Peter Zijlstra , LKML , Andrew Morton , Christoph Hellwig , "Rafael J. Wysocki" References: <20071222192550.GD28891@thunk.org> <20071222221050.GA20753@1wt.eu> <20071223051241.GA4449@1wt.eu> <20071223141500.GB6430@one.firstfloor.org> <20071224034530.GB16658@thunk.org> <20071224233701.GB9784@kernel.org> <20071225033418.GA29199@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071225033418.GA29199@one.firstfloor.org> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-Spam-Flag: NO X-Spam-Score: 0.00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1469 Lines: 30 On Tue, Dec 25, 2007 at 04:34:18AM +0100, Andi Kleen wrote: > > And is /sys/slab > > guaranteed to be a stable and permanent interface if the SLAB > > Debugging feature and "stable and permanent" just don't > fit together. It's like requesting stable and permanent > sysrq output. Yeah, unfortunately, querying to find out how much memory is being used by which parts of the system is something which I think needs to be more than just a debugging feature. One could argue that "vmstat", "iostat", and "sar" are debugging features as well, but other people would consider them "critical programs to get information necessary to monitor the health of their system". Perhaps /proc/slabinfo should be that relatively stable interface, if /sys/slab can't be guaranteed to be stable. But there *are* people who will want to monitor information like this on an ongoing fashion on production systems. One of the major downsides of /sys seems to be that it's very hard to keep it stable, so maybe it's not the right tool for this. /proc/slabinfo has the advantage that it's a simple text file, and its format is relatively well-understood, and doesn't a patch to provide /proc/slabinfo for SLUB already exist? - Ted -- 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/