From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3ACC2836B4 for ; Fri, 5 Sep 2025 09:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757064038; cv=none; b=c2Nh3W+j7DJQ6WJNv4RLtoIOyYjYZRpan5hlMrLmE3s2/qBJ/mOpxAHEUPabQjHxkwl7S/C+IkiI9HToyL/36/XZzJD+S3HwzAWkNmf59O71/UkKIDejHA1oN/93onrb6BPZXdhkLQj4LMF2cTugu5TJG9mLt0JhquxovHWVNwQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757064038; c=relaxed/simple; bh=oM2tmimwc3NuazIswcDXdIxLK21NTDotdqDLkd3Ro3c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BYJQvK2V0useymlqOB+drV5r/2tm0LH4ou2EBHyOO6r36E07KWAOORco7P8n9BsqZdDl1B4uILYuyRFQMBllUeecV/6tshKPlLo422acBM5bnZRJEc8a6zn4VwBFev1zqG7qKNqdB2iXZ0G5ztaIeLoKo7CystJcu+jiQSxNCUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=brXeq3FC; arc=none smtp.client-ip=209.85.221.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="brXeq3FC" Received: by mail-wr1-f52.google.com with SMTP id ffacd0b85a97d-3dce6eed889so1552025f8f.0 for ; Fri, 05 Sep 2025 02:20:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1757064034; x=1757668834; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Cn5dEdZ+lZHL1bSbN7KhfCFXfCyJi17J1T7WYwt+oY4=; b=brXeq3FCmhCNev8GyIcu02f4LaTGXbxjD0oJf5Ovds0+G6y44ea+QIOolhFBWVbcJ4 4s9VG0MH7/1xgXRx3L7rF65xvkswBqzSsGnNq+4X4lsJ6L8qakzvgfze3HNaHOpxVAGY YC0CvWHLRXHaUXDL8vbS856vpVuSCLErNOJAgOf/ElDL22WDC+C3ohni/cX5CYkkAK/r rifHOrds9vftVCHrBuW55T2QpHvH5OYMrUmkA1AsABVc4ZuEZlmYBrrIB705wymhFBou +5bxr5M1eSgWJ7WV0jQa1qkj6x44GtenCShZ6x8GHWYobrVn8pW9SDoNaA1TsOTmPPEY 0gxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757064034; x=1757668834; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Cn5dEdZ+lZHL1bSbN7KhfCFXfCyJi17J1T7WYwt+oY4=; b=JE+dgix5sQHOXNDN/iegTmh30gpkrJgi+QKSTv4DS+N8308IKFrMulL0A7ZIHNv4dl YClnMc1RPEH769kBeFUBBvelflaakXig+fPSgd/Pmor8yyIr6ioR8c8zN53B3pWS1kib WVHtBchIkkLGCg29mFYE9BY2Y/j6sNV3Cbk1F+ZouIEajNKfvnK3zicRzKLWpCOAM6u2 r/w0T+aka/Fs80kzYlK9dYQOHd6ZghaIFAy5KEPS9ijeoUEYDvU6jWpF+BpJZvXyP1Ia st7jSaDFOWlfzUXEa/l3ZQEbgAzu39Yr14tWArKug/5iHsbI10/4DDJ2u7D/Jsj7UHNI 0PNQ== X-Forwarded-Encrypted: i=1; AJvYcCWnz5foNps3CJubtRUx485eBf9TRJi7bNzUEdvaDViyrMMuoolHOB1+ljxkpkuQBsrRJAiA7WQ8gqDzDu0=@vger.kernel.org X-Gm-Message-State: AOJu0YwkVxAEYaRLdixn+Eaa5iZLq6Y752iaPfftc7eyGwejTvmKL9MX 7mOSwqRms/ukI73X0eHw4ccQVYbtT1oKIMKARLnXnCi9kkEVtT5i/4zLdKOWg6n8rGY= X-Gm-Gg: ASbGncuMjMSgf0hftAz9+SQRq2eLMJqvValxjfXAWuN8nRv6Q6DbPC/g2PfQAeF+zx9 +pmoc3jbDMwxSWj0JTp73MA+g67yn7gR9GCw9wfuljitYwy2zBGfxsRodz5NcmYUn3JcEDEPvAb zvxRI7yDCJx5x5Cv50KUYC5q0mN00UaGt3mdX7wHODc0z32Cm+iPtYdep5KqRzM0iyKbDl/kePb xM1Tn1Grd6WiSUt0Tl6vcFDGtbfnYV2qAkuogP9xhTdjWHQP+Jn9Dck61p5b65TUI30KN7VsLka 4yaeLHDO0jhzEHTjBNYImgvChsbJP/BZVaSIl9qjZf4Msy2zjlYmojKx5Dyp7gOwjeHweVYhfQJ NO0W8ooU6LMVp9tlNhH3P1suSxDyxVSkp X-Google-Smtp-Source: AGHT+IH/8fhX/fgj2tMYfhp5tk0xz7+PqaSeuV56lrf1jk5bI4HL3PlQBpwu2LI3QZpIRCEAOgjxYQ== X-Received: by 2002:a05:6000:2f8a:b0:3e3:921b:659f with SMTP id ffacd0b85a97d-3e3922aad5cmr1139388f8f.2.1757064034085; Fri, 05 Sep 2025 02:20:34 -0700 (PDT) Received: from localhost (109-81-31-43.rct.o2.cz. [109.81.31.43]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-3cf276d5816sm30579447f8f.25.2025.09.05.02.20.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Sep 2025 02:20:33 -0700 (PDT) Date: Fri, 5 Sep 2025 11:20:33 +0200 From: Michal Hocko To: "Liam R. Howlett" Cc: zhongjinji , rientjes@google.com, shakeel.butt@linux.dev, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, lorenzo.stoakes@oracle.com, surenb@google.com, liulu.liu@honor.com, feng.han@honor.com Subject: Re: [PATCH v7 2/2] mm/oom_kill: The OOM reaper traverses the VMA maple tree in reverse order Message-ID: References: <20250903092729.10611-1-zhongjinji@honor.com> <20250903092729.10611-3-zhongjinji@honor.com> <7rvwvuifkav5oz4ftfuziq23wek2bn6ygvrfotpaweypuy7obv@hjuf3eknscii> Precedence: bulk X-Mailing-List: linux-kernel@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: On Thu 04-09-25 22:12:48, Liam R. Howlett wrote: > * Michal Hocko [250904 08:21]: > > On Wed 03-09-25 15:02:34, Liam R. Howlett wrote: > > > * Michal Hocko [250903 08:58]: > > > > On Wed 03-09-25 17:27:29, zhongjinji wrote: > > [...] > > > mmu_notifier_release(mm) is called early in the exit_mmap() path should > > > cause the mmu notifiers to be non-blocking (according to the comment in > > > v6.0 source of exit_mmap [1]. > > > > I am not sure I follow you here. How does this relate to the actual > > direction of the address space freeing? > > It doesn't relate to the direction of the address freeing, I think it > explains the perf data a bit. > > The exit_mmap() would have a decrease in mmu related work while this > thread will have an increase, I think. > > If they race, this thread gets virtually nothing while exit does all of > the work. If they don't race then the work is split. > > Does that make sense? OK, I can see what you mean now. Thanks! I believe we need more data to understand what is actually going on here. Having the overall duration should help to get that. -- Michal Hocko SUSE Labs