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[141.239.149.160]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-78e38c951c6sm6804246a12.61.2024.07.17.18.24.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jul 2024 18:24:50 -0700 (PDT) Sender: Tejun Heo Date: Wed, 17 Jul 2024 15:24:49 -1000 From: Tejun Heo To: Waiman Long Cc: David Finkel , Johannes Weiner , Michal Hocko , Muchun Song , Andrew Morton , core-services@vimeo.com, Jonathan Corbet , Roman Gushchin , Shuah Khan , 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> <20240717170408.GC1321673@cmpxchg.org> <20240717204453.GD1321673@cmpxchg.org> <85a67b00-9ae7-42a1-87e0-19b5563b9a0f@redhat.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=us-ascii Content-Disposition: inline In-Reply-To: <85a67b00-9ae7-42a1-87e0-19b5563b9a0f@redhat.com> On Wed, Jul 17, 2024 at 07:48:40PM -0400, Waiman Long wrote: ... > How about letting .peak shows two numbers? The first one is the peak since > the creation of the cgroup and cannot be reset. The second one is a local > maximum that can be reset to 0. We just to keep track of one more counter > that should be simple enough to implement. What Johannes suggested seems to hit all the marks - it's efficient and relatively simple, the overhead is only on the users of the facility, and flexible in a straightforward manner. I have a hard time buying the argument that it's more difficult to use - the benefit to cost ratio seems pretty clear. Given that, I'm not sure why we'd want to add something fishy that can lead to longterm problems. Thanks. -- tejun