Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941564AbcLVV4i (ORCPT ); Thu, 22 Dec 2016 16:56:38 -0500 Received: from mail-qt0-f195.google.com ([209.85.216.195]:36093 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753453AbcLVV4g (ORCPT ); Thu, 22 Dec 2016 16:56:36 -0500 MIME-Version: 1.0 In-Reply-To: References: <20161126201534.5d5e338f678b478e7a7b8dc3@gmail.com> <20161129143916.f24c141c1a264bad1220031e@linux-foundation.org> From: Dan Streetman Date: Thu, 22 Dec 2016 16:55:54 -0500 X-Google-Sender-Auth: 2-S49S7WM9PrWXtMnCp9orf-KWU Message-ID: Subject: Re: [PATCH 0/2] z3fold fixes To: Vitaly Wool Cc: Andrew Morton , Linux-MM , linux-kernel , Arnd Bergmann , Dan Carpenter Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id uBMLuiZS025256 Content-Length: 3937 Lines: 87 On Sun, Dec 18, 2016 at 3:15 AM, Vitaly Wool wrote: > On Tue, Nov 29, 2016 at 11:39 PM, Andrew Morton > wrote: >> On Tue, 29 Nov 2016 17:33:19 -0500 Dan Streetman wrote: >> >>> On Sat, Nov 26, 2016 at 2:15 PM, Vitaly Wool wrote: >>> > Here come 2 patches with z3fold fixes for chunks counting and locking. As commit 50a50d2 ("z3fold: don't fail kernel build is z3fold_header is too big") was NAK'ed [1], I would suggest that we removed that one and the next z3fold commit cc1e9c8 ("z3fold: discourage use of pages that weren't compacted") and applied the coming 2 instead. >>> >>> Instead of adding these onto all the previous ones, could you redo the >>> entire z3fold series? I think it'll be simpler to review the series >>> all at once and that would remove some of the stuff from previous >>> patches that shouldn't be there. >>> >>> If that's ok with Andrew, of course, but I don't think any of the >>> z3fold patches have been pushed to Linus yet. >> >> Sounds good to me. I had a few surprise rejects when merging these >> two, which indicates that things might be out of sync. >> >> I presently have: >> >> z3fold-limit-first_num-to-the-actual-range-of-possible-buddy-indexes.patch >> z3fold-make-pages_nr-atomic.patch >> z3fold-extend-compaction-function.patch >> z3fold-use-per-page-spinlock.patch >> z3fold-discourage-use-of-pages-that-werent-compacted.patch >> z3fold-fix-header-size-related-issues.patch >> z3fold-fix-locking-issues.patch > > My initial suggestion was to have it the following way: > z3fold-limit-first_num-to-the-actual-range-of-possible-buddy-indexes.patch this is a good one, acked by both of us; it should stay and go upstream to Linus > z3fold-make-pages_nr-atomic.patch the change itself looks ok and I acked it, but as Andrew commented the log says nothing about why it's being changed; the atomic function is slower so the log should explain why it's being changed; anyone reviewing the log history won't know why you made the change, and the change all by itself is a step backwards in performance. > z3fold-extend-compaction-function.patch this explictly has a bug in it that's fixed in one of the later patches; instead, this should be fixed up and resent. > z3fold-use-per-page-spinlock.patch i should have explicitly nak'ed this, as not only did it add a bug (fixed by the the other 'fix-' patch below) but its design should be replaced by kref counting, which your latest patch is working towards... > z3fold-fix-header-size-related-issues.patch > z3fold-fix-locking-issues.patch and these fix the known problems in the previous patches. > > I would prefer to keep the fix-XXX patches separate since e. g. > z3fold-fix-header-size-related-issues.patch concerns also the problems > that have been in the code for a while now. I am ok with folding these > into the relevant main patches but once again, given that some fixes > are related to the code that is already merged, I don't see why it > would be better. none of those patches are "merged", the last z3fold patch in Linus' tree is 43afc194 from June. Just because they're in Andrew's mmotm queue (and/or linux-next) doesn't mean they are going to be merged...(correct me please if I'm wrong there Andrew) So as you can see by my patch-by-patch breakdown, almost all of them need changes based on feedback from various people. And they are all related - your goal is to improve z3fold performance, right? IMHO they should be sent as a single patch series with that goal in the cover letter, including specific details and numbers about how the series does improve performance. > > ~vitaly > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org