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J . Mercier" , Baolin Wang , Suren Baghdasaryan , Meta kernel team , bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [LSF/MM/BPF TOPIC] Towards Unified and Extensible Memory Reclaim (reclaim_ext) Message-ID: References: <20260325210637.3704220-1-shakeel.butt@linux.dev> <20260325190547.abb7309fb63473b57b7a90a0@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspam-User: X-Rspamd-Queue-Id: 1EFEF10000F X-Stat-Signature: kicyqjcnsax5h7yp566b4pkbf6xbj1di X-Rspamd-Server: rspam06 X-HE-Tag: 1774528294-288996 X-HE-Meta: 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 CxT5nNfI eJqP4B+L9teSayFALPrT9gNVfdjWerxirLvlmrdFBI1KrCt+p86u80AYOxMLhTRXJh71fW7LGJ7LAe35vpCp9jlUAfKd2I85fb4URPFo7GxNb1PlOCXW3Jn5AlNXk0pmeEql8t3Cjuu7RhqkwJoH15raRAMTvDFjvSQEd++e5bjbFqt+pMWkFShZXGCfVnO4hYd5lpUQi9iqPvDy75woRck+k00lGMSggka7DWjvcBd4qDvDnU2AOQgzdfrBhOO9BfanQpmnafzOOX2N7rcUpzb2OTn1kphJkZCR4aMAeGuML8TqpAtpZ66sDMJO+af9m32iulh2Z0yUU9j8nxQvTN+5FKkZOvfDgiuf+5wfF3HdZQnDRtwaPLc9hLg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: +cc Gregory On Thu, Mar 26, 2026 at 08:06:13PM +0800, Kairui Song wrote: > On Thu, Mar 26, 2026 at 10:05 AM Andrew Morton > wrote: > > > > On Wed, 25 Mar 2026 14:06:37 -0700 Shakeel Butt wrote: > > > > > We should unify both algorithms into a single code path. > > > > I'm here to ask the questions which others fear will sound dumb. > > > > Is it indeed the plan to maintain both implementations? I thought the > > long-term ambition was to knock MGLRU into shape and to drop the legacy LRU? > > I personally also agree on that, so far I'm not aware of any major > issues with MGLRU except some corner cases that are not hard to fix. > Once these are done, I don't see the need for more complexity. Well... :) What about the issues Gregory raised here? https://lore.kernel.org/linux-mm/aaXM7xNSJaJBsety@gourry-fedora-PF4VCD3F/ > > > > And that Linus has expressed such a desire, but my googling fails me. Yup I know, and it'd be ideal to have a single approach, but we definitely need a little more assurance this time that it's the right choice :) In any case I do agree with Shakeel that de-duplicating the code and 'stealing' good ideas from it for both flavours of reclaim at least to start with is a good way forwards. Once we've done that, we can work towards eliminating the 'classic' reclaim if the data supports it. Thanks, Lorenzo