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h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Di+wr37U174Nx7w1oJa4ec3u7LAPibr5Hnogm0KQ5KA=; b=UcJCyd2p+mYe2Wqf/j6TBXBwYPGlCzid/IAMlic1rWsM2ixQoGh0VjXXAGyGkxee8w FIF0MopveZK4vOALjH6Dk6Rw/cuPVUTiERoRmJ6N66NIEl4Ke9DA4YpwecouSXhsiQRg 7XqM4wqSI6zqLHBF31A3J2aHLmDMninBxggjymoqHQ4uoa7/oS6xCOe7I5JF0nxNk86W dcvrxXV5VihzGJID5YUbFr1lqZd4nRt0dOWr5B+OD5N7zIIFrAxxw2a1m34hz8zdq9QL 2LvoRUVw4bQnzWhl6NMgu76uAK9f6NOfrRJpSpp6aOTODlJBevN2Of5JVzvKgF8CfFuO WS8Q== X-Gm-Message-State: AOAM532IK6tb0FrLOOtIG45fyR56On+4Bv6GO4JTBf7oXOTGzrQ5DJsy R6r3RCa71wBULqjBzuQg9ZdS1eRJ+ctyaWy1lcHAxw== X-Google-Smtp-Source: ABdhPJz/nQA8xxiMNDyTW4PUrlucKA7LqqG3BlyYwzZ4ZVXZvD8oivYN5l/8PMooP8q1SwXigPcaj8U6TIwW9K1TzWs= X-Received: by 2002:a05:6102:5cc:b0:320:9bd2:3823 with SMTP id v12-20020a05610205cc00b003209bd23823mr2650275vsf.81.1650000658866; Thu, 14 Apr 2022 22:30:58 -0700 (PDT) MIME-Version: 1.0 References: <20220407031525.2368067-1-yuzhao@google.com> <20220407031525.2368067-9-yuzhao@google.com> <20220411191621.0378467ad99ebc822d5ad005@linux-foundation.org> <20220412071026.GU2731@worktop.programming.kicks-ass.net> In-Reply-To: <20220412071026.GU2731@worktop.programming.kicks-ass.net> From: Yu Zhao Date: Thu, 14 Apr 2022 23:30:22 -0600 Message-ID: Subject: Re: [PATCH v10 08/14] mm: multi-gen LRU: support page table walks To: Peter Zijlstra Cc: Andrew Morton , Stephen Rothwell , Linux-MM , Andi Kleen , Aneesh Kumar , Barry Song <21cnbao@gmail.com>, Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Jesse Barnes , Johannes Weiner , Jonathan Corbet , Linus Torvalds , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Mike Rapoport , Rik van Riel , Vlastimil Babka , Will Deacon , Ying Huang , Linux ARM , "open list:DOCUMENTATION" , linux-kernel , Kernel Page Reclaim v2 , "the arch/x86 maintainers" , Brian Geffon , Jan Alexander Steffens , Oleksandr Natalenko , Steven Barrett , Suleiman Souhlal , Daniel Byrne , Donald Carr , =?UTF-8?Q?Holger_Hoffst=C3=A4tte?= , Konstantin Kharlamov , Shuang Zhai , Sofia Trinh , Vaibhav Jain Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=HODn7qI5; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf13.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.50 as permitted sender) smtp.mailfrom=yuzhao@google.com X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: C283E20009 X-Stat-Signature: 15fhr7qemkk3up74jbz8ydm11bsiff5h X-HE-Tag: 1650000659-560530 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 12, 2022 at 1:10 AM Peter Zijlstra wrote: > > On Mon, Apr 11, 2022 at 07:16:21PM -0700, Andrew Morton wrote: > > On Wed, 6 Apr 2022 21:15:20 -0600 Yu Zhao wrote: > > > > +#ifdef CONFIG_LRU_GEN > > > +static void mem_cgroup_attach(struct cgroup_taskset *tset) > > > +{ > > > + struct cgroup_subsys_state *css; > > > + struct task_struct *task = NULL; > > > + > > > + cgroup_taskset_for_each_leader(task, css, tset) > > > + break; > > > > Does this actually do anything? > > Yeah, it finds the first leader if there is any, but this is indeed > quite terrible coding style. I've added a one liner comment "find the first leader if there is any", for now. I'm open to other suggestions.