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[109.81.86.75]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a79bc5a3a93sm460671166b.6.2024.07.17.08.46.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jul 2024 08:46:45 -0700 (PDT) Date: Wed, 17 Jul 2024 17:46:44 +0200 From: Michal Hocko To: David Finkel Cc: Tejun Heo , Muchun Song , Andrew Morton , core-services@vimeo.com, Jonathan Corbet , Roman Gushchin , Shuah Khan , Johannes Weiner , Zefan Li , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Shakeel Butt Subject: Re: [PATCH] mm, memcg: cg2 memory{.swap,}.peak write handlers Message-ID: References: <20240715203625.1462309-1-davidf@vimeo.com> <20240715203625.1462309-2-davidf@vimeo.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed 17-07-24 10:24:07, David Finkel wrote: > On Wed, Jul 17, 2024 at 2:26 AM Michal Hocko wrote: > > > > On Tue 16-07-24 18:06:17, David Finkel wrote: [...] > > > I'm thinking of something like "global_reset\n", so if we do something like the > > > PSI interface later, users can write "fd_local_reset\n", and get that > > > nicer behavior. > > > > > > This also has the benefit of allowing "echo global_reset > > > > /sys/fs/cgroup/.../memory.peak" to do the right thing. > > > (better names welcome) > > > > This would be a different behavior than in v1 and therefore confusing > > for those who rely on this in v1 already. So I wouldn't overengineer it > > and keep the semantic as simple as possible. If we decide to add PSI > > triggers they are completely independent on peak value because that is > > reclaim based interface which by definition makes peak value very > > dubious. > > That's fair. > > My only thought is that "write any non-empty string", is a very wide interface > to support, and limits other possible behaviors later. yes, that ship has sailed long time ago. -- Michal Hocko SUSE Labs