From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752094AbYCKXN5 (ORCPT ); Tue, 11 Mar 2008 19:13:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750863AbYCKXNu (ORCPT ); Tue, 11 Mar 2008 19:13:50 -0400 Received: from n6.bullet.mud.yahoo.com ([216.252.100.57]:21397 "HELO n6.bullet.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750765AbYCKXNt (ORCPT ); Tue, 11 Mar 2008 19:13:49 -0400 X-Yahoo-Newman-Id: 875086.47066.bm@omp409.mail.mud.yahoo.com DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=eye+Yvm0aSFXY8kNWmt+n/zraS6iNFA5mEss22VZwoigG+8HSO70VsKu+Kol2KELpyc5nUYHtyijI8eMKM/6MCXGyvYdR3zrT8oCP1QaOCKC+UmakpC0BiWXmDMypDrG4nXWtf23UgdjR1yNF46aIiIMVQoFlo+zHn60D4D3j2E= ; X-YMail-OSG: uNfd5Q0VM1l1Gf0foaaH2.3EaKw3J.cTF_JVe7qjI9ixOZYSTEvNwZZhW789LuTTL4_xHYbjJA-- X-Yahoo-Newman-Property: ymail-3 From: Nick Piggin To: "Pekka Enberg" Subject: Re: [RFC PATCH] Implement slub fastpath with sequence number Date: Wed, 12 Mar 2008 10:13:20 +1100 User-Agent: KMail/1.9.5 Cc: "Mathieu Desnoyers" , "Christoph Lameter" , linux-kernel@vger.kernel.org References: <20080311093144.GB30220@Krystal> <200803112041.09217.nickpiggin@yahoo.com.au> <84144f020803110745jcc73368l84e2268b68133520@mail.gmail.com> In-Reply-To: <84144f020803110745jcc73368l84e2268b68133520@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200803121013.20810.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 12 March 2008 01:45, Pekka Enberg wrote: > Hi Nick, > > On Tue, Mar 11, 2008 at 11:41 AM, Nick Piggin wrote: > > Wow. I applaud the effort to micro optimise things ;) > > > > But I hope this doesn't get merged until macro-regressions in SLUB > > are verified to be fixed. It's pretty clear that SLUB's problem is > > not fastpath performance, so I think this would be premature > > optimisation. > > What regressions are you referring to? The SLAB_HWCACHE_ALIGN > regression patch you sent is being merged. What else? The oracle/tpcc one I don't know if it has been fixed? > And FWIW, I don't like the patch because it makes the code very hairy. > But I don't see why we shouldn't merge SLUB fast-path optimizations if > they're clean and you have the numbers to show it's a gain even if > there are other remaining regressions. I'm talking about this patch specifically though. It makes it much harder to work with.