From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26E6EC3DA59 for ; Tue, 16 Jul 2024 13:54:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B2E636B00A4; Tue, 16 Jul 2024 09:54:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ADE716B00A5; Tue, 16 Jul 2024 09:54:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A6566B00A8; Tue, 16 Jul 2024 09:54:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7577D6B00A4 for ; Tue, 16 Jul 2024 09:54:54 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id DD2FBA33B1 for ; Tue, 16 Jul 2024 13:54:53 +0000 (UTC) X-FDA: 82345761666.09.99B84B3 Received: from mail-pg1-f171.google.com (mail-pg1-f171.google.com [209.85.215.171]) by imf19.hostedemail.com (Postfix) with ESMTP id EF4A61A0009 for ; Tue, 16 Jul 2024 13:54:51 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=vimeo.com header.s=google header.b=KvpGIgUm; spf=pass (imf19.hostedemail.com: domain of davidf@vimeo.com designates 209.85.215.171 as permitted sender) smtp.mailfrom=davidf@vimeo.com; dmarc=pass (policy=reject) header.from=vimeo.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1721138072; a=rsa-sha256; cv=none; b=mWyzVZtGsl2yclOuEYZ+zd0ti8hyD6Epcs3lvZuYhiYeb0sNf5IxDfRkZlWKaa3N0C5Xex H8I2/wKsKAXZFObTtQezl66FbQxmGZbmAuGkRAMz/k9gwPYezFu2+3EFHD8/LiF3h1x0dt miEdgBdERdLUSJxTbXRHWoLmfCL90is= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=vimeo.com header.s=google header.b=KvpGIgUm; spf=pass (imf19.hostedemail.com: domain of davidf@vimeo.com designates 209.85.215.171 as permitted sender) smtp.mailfrom=davidf@vimeo.com; dmarc=pass (policy=reject) header.from=vimeo.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1721138072; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=WfYT81X+JbtIPMlAO3YtYDsv4qp4U3lPBqzIZ0idfpM=; b=6OaclFtNeJle3Gx7rpupUslUWazBmg34lzFeVzUfICePwnkrQvTpj6BZLm0xnzM8ght10M 68xA/HnO0dNZBJ9ec8P/J6EPcqpL7qPUCHer7rkFCu1ErgcptRyJHtmZo4EMRqOKu9OdzY q55t/bwk5KiczaWM9UJPdR2nG3dfKZM= Received: by mail-pg1-f171.google.com with SMTP id 41be03b00d2f7-7515437ff16so3980040a12.2 for ; Tue, 16 Jul 2024 06:54:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vimeo.com; s=google; t=1721138091; x=1721742891; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=WfYT81X+JbtIPMlAO3YtYDsv4qp4U3lPBqzIZ0idfpM=; b=KvpGIgUmtuANjeO4QDqCnvMf+nLVTlgyq6b/meWGSwT5X9f4k7bv9cntOBUriNu8gr F0qmxlAwu0pYMSaWRbl9/GguVmGg89xaJ21CBtC+4AD7LDY6y5OCTwb5q0XYFoHHKVxb AgqMAdpk/dvT6sGI+u26VbE6rweTWj/6KUsp0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721138091; x=1721742891; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WfYT81X+JbtIPMlAO3YtYDsv4qp4U3lPBqzIZ0idfpM=; b=EFYUzHn+e5Ht49/K1fBIssfTOKIaoDzZ7ogKucGI5HSkTujt7jnRtlrF9xhlDH/3R4 HQdYVKyTcPNrU4Cq5xWb64+KR2KydJ1fDfepSSpHnY1HTRLGju0gMjCAhFXFV28XgY8o 2U1yTPqxtv2reNawXFNEdPpO/EaLMsqXti3RonRxVVzFeFec02q0XBWTistylD7RzYoJ 3s2cQ3Lchi2fcrJpp9NElbbofLakuVFGSK1aBBn5yaXi3OG8J/OX2o0ytiNrNs4Sh2TV ix8tv75nTRWcWqN/kPIDHAE+geEgNyLz8N9Zftu6S0TPKbKxi69MoP7kL7VrGorobK8j SETA== X-Forwarded-Encrypted: i=1; AJvYcCV69wxgY0xGxFzM4Fb8K7mqm9PLYd6LYmb5VvNZb0TuQQrTMyxksChlQC9+SLQ0U3aiIjxPD3EVqSsp1msDsQ51DTQ= X-Gm-Message-State: AOJu0YyX98D4siKYB+dQjJySgZ3dioVNym3LbVqZUiiq+NfcSjje4qwo mZaTAqiQEdgoSA/1hcpmEIrdcRPaj6SUxl2d1/x02Awu66eJdTi56c5jD1ZaPSQW6z7XnqXjmqt WhUC5z+dmWjZYkcDySR1wl/M113uNP3llzlJHHA== X-Google-Smtp-Source: AGHT+IGx+cRRXemzKapP9hmTTeHrWTch3dG3LS+Iq9Go5gHj7UbxSEnrer9YRngu4o/b6ia21geBCVOSzUYPjswdzuM= X-Received: by 2002:a05:6a20:12c7:b0:1c2:74b4:a05d with SMTP id adf61e73a8af0-1c3f122d75cmr2556165637.23.1721138090450; Tue, 16 Jul 2024 06:54:50 -0700 (PDT) MIME-Version: 1.0 References: <20240715203625.1462309-1-davidf@vimeo.com> <20240715203625.1462309-2-davidf@vimeo.com> In-Reply-To: From: David Finkel Date: Tue, 16 Jul 2024 09:54:39 -0400 Message-ID: Subject: Re: [PATCH] mm, memcg: cg2 memory{.swap,}.peak write handlers To: Michal Hocko Cc: Muchun Song , Andrew Morton , core-services@vimeo.com, Jonathan Corbet , Roman Gushchin , Shakeel Butt , Shuah Khan , Johannes Weiner , Tejun Heo , Zefan Li , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: 5u5yxxmjdgamo6uw5isp6x4pfbp1qtk6 X-Rspamd-Queue-Id: EF4A61A0009 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1721138091-891466 X-HE-Meta: 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 HV36Xn/f prxdsnJwrRVQbYX8OYJ4gSMPEgoSizC2HwRdXY2mj3VFnjfScPaXY3f/A2yXzDUVeh3Fe4RuKpB+UnjBH8tEca+EIpkJyLQGtbeaCobt/YH/pbJo/GiG4HnzNFHhLmjUOlbe612OP2evQB4cO94nA/eRLlzXo2o5rfSVup3yvbGokFK+B7T89myObGXCuUgvzzinZ9Bxn6jYaE3w8Hj7iL1ocdLiMCRb261d9f7wSfvuX7hsrjje4C8zQIg== 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: List-Subscribe: List-Unsubscribe: On Tue, Jul 16, 2024 at 9:48=E2=80=AFAM Michal Hocko wrot= e: > > On Mon 15-07-24 16:36:26, David Finkel wrote: > > Other mechanisms for querying the peak memory usage of either a process > > or v1 memory cgroup allow for resetting the high watermark. Restore > > parity with those mechanisms. > > > > For example: > > - Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets > > the high watermark. > > - writing "5" to the clear_refs pseudo-file in a processes's proc > > directory resets the peak RSS. > > > > This change copies the cgroup v1 behavior so any write to the > > memory.peak and memory.swap.peak pseudo-files reset the high watermark > > to the current usage. > > > > This behavior is particularly useful for work scheduling systems that > > need to track memory usage of worker processes/cgroups per-work-item. > > Since memory can't be squeezed like CPU can (the OOM-killer has > > opinions), these systems need to track the peak memory usage to compute > > system/container fullness when binpacking workitems. > > > > Signed-off-by: David Finkel > > As mentioned down the email thread, I consider usefulness of peak value > rather limited. It is misleading when memory is reclaimed. But > fundamentally I do not oppose to unifying the write behavior to reset > values. > > The chnagelog could use some of the clarifications down the thread. Sure, I can spend some time rewording the changelog this afternoon, and remail it. in a few hours. > > Acked-by: Michal Hocko > Thank you! > -- > Michal Hocko > SUSE Labs --=20 David Finkel Senior Principal Software Engineer, Core Services