From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: Re: [PATCH 0/22] Immutable biovecs, block layer changes Date: Tue, 24 Sep 2013 12:19:54 -0700 Message-ID: <20130924191954.GB2636@kmo-pixel> References: <1375912471-5106-1-git-send-email-kmo@daterainc.com> <20130808150954.GA30092@infradead.org> <20130808211529.GB15409@kmo-pixel> <20130924110012.GA7160@infradead.org> <20130924132014.GA16165@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , axboe@kernel.dk, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org To: Mike Snitzer Return-path: Received: from mail-pb0-f45.google.com ([209.85.160.45]:53333 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754624Ab3IXTUF (ORCPT ); Tue, 24 Sep 2013 15:20:05 -0400 Received: by mail-pb0-f45.google.com with SMTP id mc17so4968930pbc.4 for ; Tue, 24 Sep 2013 12:20:04 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20130924132014.GA16165@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Sep 24, 2013 at 09:20:14AM -0400, Mike Snitzer wrote: > On Tue, Sep 24 2013 at 7:00am -0400, > Christoph Hellwig wrote: > > > Just curious, what's the state of the remaining immutable bio work? > > Hey Christoph, > > Have you been over the patchset? Looks sane to you? > > Given how disruptive this patchset is to the block layer I'm wondering > how painful this change will be in combination with Jens' blk-mq > changes. I'd prefer to see blk-mq before immutable biovecs; but I have > my own selfish reasons for that. > > I'm also concerned about DM regressions given that a lot of DM code to > handle splitting a bio that spans target boundaries is ripped out, see: > https://patchwork.kernel.org/patch/2840657/ Oh good, you had seen that :) Are you worried about performance regressions or actual bugs? I _have_ explicitly tested that code path, but I don't know what corner cases I may have missed so it definitely needs your eyeballs and testing too. As for performance - this'll be more efficient than what the dm code was doing before. Especially when the multipage bvec patches go in. > But that is just handwaving/FUD at this point cause I haven't put the > time to looking at this patchset close enough to feel comfortable. I > can make reviewing this patchset a priority this week though. > > Kent, have you rebased this patchset at all? Do you have a git tree I > can clone to save the pain of pulling these patches out my my mbox, > etc. Yeah: git://evilpiepirate.org/~kent/linux-bcache.git for-jens