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[35.188.239.129]) by smtp.gmail.com with ESMTPSA id o2-20020a05620a110200b0071bfeaf5688sm7734578qkk.72.2023.02.01.02.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Feb 2023 02:25:25 -0800 (PST) Date: Wed, 1 Feb 2023 10:25:25 +0000 From: Joel Fernandes To: lsf-pc@lists.linux-foundation.org Cc: Frederic Weisbecker , "Paul E. McKenney" , Steven Rostedt , linux-mm , rcu Subject: LSFMMBPF proposal [MM]: Lazy RCU memory reclaim Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Stat-Signature: qu6dfwfb9axh8bq54icqzdzsff4bedne X-Rspam-User: X-Rspamd-Queue-Id: 4B6641A000F X-Rspamd-Server: rspam06 X-HE-Tag: 1675247127-669259 X-HE-Meta: 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 ODbaI7hL HaUP1W/Z+bxAt2FqproFEk7ktt1/TEgRNQm5AZGOtz/vqnx7a2z8o/3eQNXYlTSWdusWuHHxGQR9x5JdW2MCtZp7DyK/50+3Z3O4cm6mXizWHj8WR6/MbQkoUQ20ByyiOB61ob2GORl7Iab8tRfNuHkh84qTB77gstsJx64JJjnby/lKDpEaK70Pxfg8j3RyvfJMwbu/gzTBpJUHYDkPE0zEBY0FFVHQMFWTjB1hebn0UrGrHEF3tipG3piCpJ/nypIJSEfS7WDDi6dBhbUzBy86j7iNKga5zi/mw X-Bogosity: Ham, tests=bogofilter, spamicity=0.047139, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Title: Lazy RCU memory reclaim: Design, mainlining and next steps Description: Lazy RCU is a new technique introducing multi-second delays in RCU memory reclaim, done to save power on Android and ChromeOS. This talk is to describe the internals of how this works, and issues encountered. We will also discuss the mainlining of the patches, and future work. It is desired to also garner more interest in the -mm community and spread awareness of this work, including future work: * Delaying reclaim for other flavors of RCU (such as SRCU). * Possible integration of delayed free'ing into the slab (FreeBSD does this for their equivalent of RCU, for instance). * Development of tooling to monitor RCU activity (BPF or otherwise). * Any positive or negative effects on usecases we should know about (per-VMA locks, BPF etc). thanks, - Joel