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Wed, 14 Oct 2026 06:55:26 -0400 (EDT) Date: Wed, 14 Oct 2026 11:55:25 +0100 From: Kiryl Shutsemau To: "David Hildenbrand (Arm)" Cc: Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Jann Horn Subject: Re: [PATCH v4 10/13] mm/collapse: open-code collapse_single_pmd() in its two callers Message-ID: References: <20260928100630.21870-1-kirill@shutemov.name> <20260928100630.21870-11-kirill@shutemov.name> <20261013143839.832f1a4db51f801a2b95f850@linux-foundation.org> <3bd88620-c245-4fab-abb7-9091d9a1b649@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3bd88620-c245-4fab-abb7-9091d9a1b649@kernel.org> On Wed, Oct 14, 2026 at 11:33:46AM +0200, David Hildenbrand (Arm) wrote: > On 10/13/26 23:38, Andrew Morton wrote: > > On Tue, 13 Oct 2026 22:25:21 +0200 "David Hildenbrand (Arm)" wrote: > > > >>> > >>> I see the appeal of the single entry point for the collapse engine. I do. > >>> > >>> But it costs us on both the locking picture and the scan rate. That > >>> does not work for me. > >> > >> So this is in mm-unstable and I want at least the first 9 patches to go to > >> mm-stable rather sooner than later. > >> > >> As raised in person, I don't like the open-coding here; it just results in weird > >> API. I wonder whether we can come up with a better interface, while keeping the > >> locking as per your requirement cheap (scan performance). > >> > >> While we figure that out, does it make sense to send out revised patch 1..9 to > >> move them to mm-stable while we figure out the remainder of the new API? > > > > I've suggested to Kyril that we park this series until the next -rc > > cycle. > > > > But I can bring it back - we have a couple of weeks, three if we get a > > 3-week merge window. > > I'd say we move forward with the uncontroversial parts, and keep discussing the > controversial bits. Either these make it still in this cycle or we'll simply > have them for the next cycle. Agreed. Andrew, could you pick up 1-9 and leave 10-13 out for now? I want to experiment with a few ideas for the rest and will get back. -- Kiryl Shutsemau / Kirill A. Shutemov