Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 18 Nov 2022 15:42:34 -0500
From:   Johannes Weiner <hannes@cmpxchg.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Hugh Dickins <hughd@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Matthew Wilcox <willy@infradead.org>,
        David Hildenbrand <david@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>, Peter Xu <peterx@redhat.com>,
        Yang Shi <shy828301@gmail.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Sidhartha Kumar <sidhartha.kumar@oracle.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Naoya Horiguchi <naoya.horiguchi@linux.dev>,
        Mina Almasry <almasrymina@google.com>,
        James Houghton <jthoughton@google.com>,
        Zach O'Keefe <zokeefe@google.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 0/3] mm,thp,rmap: rework the use of subpages_mapcount
Message-ID: <Y3fuOo2MPdGHG4lW@cmpxchg.org>
References: <5f52de70-975-e94f-f141-543765736181@google.com>
 <c4b8485b-1f26-1a5f-bdf-c6c22611f610@google.com>
 <CAHk-=whmq5gHrKmD3j=7nB=n9OmmLb5j1qmoQPHw1=VSQ-V=hg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAHk-=whmq5gHrKmD3j=7nB=n9OmmLb5j1qmoQPHw1=VSQ-V=hg@mail.gmail.com>
Precedence: bulk

On Fri, Nov 18, 2022 at 12:18:42PM -0800, Linus Torvalds wrote:
> On Fri, Nov 18, 2022 at 1:08 AM Hugh Dickins <hughd@google.com> wrote:
> >
> > Linus was underwhelmed by the earlier compound mapcounts series:
> > this series builds on top of it (as in next-20221117) to follow
> > up on his suggestions - except rmap.c still using lock_page_memcg(),
> > since I hesitate to steal the pleasure of deletion from Johannes.
> 
> This looks good to me. Particularly 2/3 made me go "Aww, yes" but the
> overall line removal stats look good too.
> 
> That said, I only looked at the patches, and not the end result
> itself. But not having the bit spin lock is, I think, a huge
> improvement.
> 
> I do wonder if this should be now just merged with your previous
> series - it looks a bit odd how your previous series adds that
> bitlock, only for it to be immediately removed.
> 
> But if you think the logic ends up being easier to follow this way as
> two separate patch series, I guess I don't care.
> 
> And the memcg locking is entirely a separate issue, and I hope
> Johannes will deal with that.

Yeah, I'll redo the removal on top of this series and resend it.

Thanks