From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 04 Oct 2007 01:16:22 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by oss.sgi.com (8.12.11.20060308/8.12.10/SuSE Linux 0.7) with ESMTP id l948GFrW012998 for ; Thu, 4 Oct 2007 01:16:18 -0700 From: Andi Kleen Subject: Re: [PATCH] XFS bitops to Linux again Date: Thu, 4 Oct 2007 10:14:22 +0200 References: <200710040027.16926.ak@suse.de> <60338.192.168.3.1.1191452291.squirrel@mail.aconex.com> In-Reply-To: <60338.192.168.3.1.1191452291.squirrel@mail.aconex.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200710041014.22936.ak@suse.de> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: nscott@aconex.com Cc: xfs@oss.sgi.com > Several of these call sites are also compiled in userspace in libxfs. It > would > be a good idea from that POV also to keep some level of abstraction so that > these calls can be mapped to userspace routines as well. Again the same argument applies -- there is no difference if you map xfs_(high|low)bit or fls64/fls/find_find_bit() to something else. > > The resulting xfs.ko is about 500 bytes smaller on x86-64 > > Thats it? It's probably a little faster too (admittedly unlikely to be really measurable in a macro benchmark) and the source code is smaller. > What testing was done? Changes to some of these routines has introuced > subtle log recovery bugs in the past - has recovery been tested at all? > The QA > suite has some log recovery tests, it'd be a good idea to verify with > those.. I had a simple separate unit test to verify the 32bit space gave the same result. The only difference was the 0 case, but I checked all inputs manually. Usually they had != 0 tests already or zero was impossible; in the few cases were not I added ASSERTs -- so if i got it wrong it should bomb out quickly. I did also some simple tests using the QA suite -- i believe a few logs were recovered -- but not the full tests. > To be honest, this sounds like just code churn and risk > introduction. Ok I got the message. I retract the patch. Sorry for bothering you with lowly cleanups. -Andi