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Tue, 26 May 2026 19:39:18 -0700 (PDT) Message-ID: <8eea0a0d-615f-ff72-b019-0634a5f1028b@gmail.com> Date: Wed, 27 May 2026 10:39:08 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH v2 0/4] mm/zswap: Implement per-cgroup proactive writeback To: Yosry Ahmed Cc: Andrew Morton , tj@kernel.org, hannes@cmpxchg.org, shakeel.butt@linux.dev, mhocko@kernel.org, mkoutny@suse.com, nphamcs@gmail.com, chengming.zhou@linux.dev, muchun.song@linux.dev, roman.gushchin@linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Hao Jia References: <20260525122242.36127-1-jiahao.kernel@gmail.com> <20260525122424.3b2818f06832d9d55da8d69b@linux-foundation.org> <9b2ac88c-a67f-2512-d898-3dadd50ec03e@gmail.com> From: Hao Jia In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2026/5/27 02:55, Yosry Ahmed wrote: > On Tue, May 26, 2026 at 4:56 AM Hao Jia wrote: >> >> >> >> On 2026/5/26 03:24, Andrew Morton wrote: >>> On Mon, 25 May 2026 20:22:38 +0800 Hao Jia wrote: >>> >>>> Zswap currently writes back pages to backing swap reactively, triggered >>>> either by the shrinker or by the pool reaching its size limit. Although >>>> proactive memory reclaim can automatically write back a portion of zswap >>>> pages via the shrinker, it cannot explicitly control the amount of >>>> writeback for a specific memory cgroup. Moreover, proactive memory reclaim >>>> may not always be triggered during a steady state. >>>> >>>> In certain scenarios, it is desirable to trigger writeback in advance to >>>> free up memory. For example, users may want to prepare for an upcoming >>>> memory-intensive workload by flushing cold memory to the backing storage >>>> when the system is relatively idle. >>>> >>>> This patch series introduces a "zswap_writeback_only" key to memory.reclaim >>>> cgroup interface, allowing users to proactively write back cold compressed >>>> pages from zswap to the backing swap device. When specified, this key >>>> bypasses standard memory reclaim and exclusively performs proactive zswap >>>> writeback up to the requested budget. If omitted, the default reclaim >>>> behavior remains unchanged. >>> >>> Thanks. AI review found a few things to complain about, one of them >>> described as "preexisting". >>> >> >> Thanks Andrew. I have replied to the AI's review comments in a separate >> email and posted v3. >> https://lore.kernel.org/all/20260526114601.67041-1-jiahao.kernel@gmail.com > > Generally speaking, please give time for reviewers to take a look > before sending a new version. Less than a day is usually too fast > (unless you're iterating super fast with the reviewers). Review > feedback does not have to be addressed immediately, usually wait for a > bit to collect as much feedback as possible before spinning a new > version. > Thanks for the advice, Yosry. Got it. > I will take a look at v3 soon, thank you. Appreciate you taking a look at v3. Thakns, Hao