From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f199.google.com (mail-qk0-f199.google.com [209.85.220.199]) by kanga.kvack.org (Postfix) with ESMTP id 86955280258 for ; Thu, 22 Dec 2016 16:56:36 -0500 (EST) Received: by mail-qk0-f199.google.com with SMTP id i145so78329201qke.5 for ; Thu, 22 Dec 2016 13:56:36 -0800 (PST) Received: from mail-qt0-x244.google.com (mail-qt0-x244.google.com. [2607:f8b0:400d:c0d::244]) by mx.google.com with ESMTPS id w143si9542708qka.155.2016.12.22.13.56.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Dec 2016 13:56:35 -0800 (PST) Received: by mail-qt0-x244.google.com with SMTP id 41so3377468qtn.0 for ; Thu, 22 Dec 2016 13:56:35 -0800 (PST) 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 Message-ID: Subject: Re: [PATCH 0/2] z3fold fixes Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Vitaly Wool Cc: Andrew Morton , Linux-MM , linux-kernel , Arnd Bergmann , Dan Carpenter 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 wro= te: >> >>> On Sat, Nov 26, 2016 at 2:15 PM, Vitaly Wool wro= te: >>> > 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 t= oo big") was NAK'ed [1], I would suggest that we removed that one and the n= ext z3fold commit cc1e9c8 ("z3fold: discourage use of pages that weren't co= mpacted") 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.pat= ch >> 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.patc= h 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 -- 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