Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754776Ab0DOPpR (ORCPT ); Thu, 15 Apr 2010 11:45:17 -0400 Received: from gir.skynet.ie ([193.1.99.77]:51110 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754720Ab0DOPpE (ORCPT ); Thu, 15 Apr 2010 11:45:04 -0400 Date: Thu, 15 Apr 2010 16:44:42 +0100 From: Mel Gorman To: Andi Kleen Cc: KOSAKI Motohiro , Dave Chinner , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 1/4] vmscan: simplify shrink_inactive_list() Message-ID: <20100415154442.GG10966@csn.ul.ie> References: <20100415085420.GT2493@dastard> <20100415185310.D1A1.A69D9226@jp.fujitsu.com> <20100415192140.D1A4.A69D9226@jp.fujitsu.com> <20100415131532.GD10966@csn.ul.ie> <87tyrc92un.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <87tyrc92un.fsf@basil.nowhere.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1505 Lines: 37 On Thu, Apr 15, 2010 at 05:01:36PM +0200, Andi Kleen wrote: > Mel Gorman writes: > > > > $ stack-o-meter vmlinux-vanilla vmlinux-2-simplfy-shrink > > add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-144 (-144) > > function old new delta > > shrink_zone 1232 1160 -72 > > kswapd 748 676 -72 > > And the next time someone adds a new feature to these code paths or > the compiler inlines differently these 72 bytes are easily there > again. It's not really a long term solution. Code is tending to get > more complicated all the time. I consider it unlikely this trend will > stop any time soon. > The same logic applies when/if page writeback is split so that it is handled by a separate thread. > So just doing some stack micro optimizations doesn't really help > all that much. > It's a buying-time venture, I'll agree but as both approaches are only about reducing stack stack they wouldn't be long-term solutions by your criteria. What do you suggest? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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/