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Tue, 26 May 2026 04:56:37 -0700 (PDT) Message-ID: <9b2ac88c-a67f-2512-d898-3dadd50ec03e@gmail.com> Date: Tue, 26 May 2026 19:56:27 +0800 Precedence: bulk X-Mailing-List: cgroups@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: Andrew Morton Cc: tj@kernel.org, hannes@cmpxchg.org, shakeel.butt@linux.dev, mhocko@kernel.org, yosry@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> From: Hao Jia In-Reply-To: <20260525122424.3b2818f06832d9d55da8d69b@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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 Thanks, Hao