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 0331AC3ABAC for ; Fri, 2 May 2025 17:26:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AA2E46B008C; Fri, 2 May 2025 13:26:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A2A046B0092; Fri, 2 May 2025 13:26:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F1C66B0093; Fri, 2 May 2025 13:26:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 6D7F06B008C for ; Fri, 2 May 2025 13:26:28 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 2F581BCBAE for ; Fri, 2 May 2025 17:26:29 +0000 (UTC) X-FDA: 83398646898.11.2910AE8 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf25.hostedemail.com (Postfix) with ESMTP id 2A4CEA000C for ; Fri, 2 May 2025 17:26:27 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=D1lcqp3G; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf25.hostedemail.com: domain of song@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=song@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1746206787; a=rsa-sha256; cv=none; b=zEBloPdgD0DkP6mE+sx96yShxfdPAk7Wm2JqQPJzGsR6kokAA801Hn1FCxKk9ZEaQvLo8A 8WwfzXIN2HntjA/0A5biD7D4aS/v9DWqHwykjMrdYZrcer7QMH0HJrFAFfrXSqw3HgovBI 7pZzDNJLeEnTk2xWdSLGnLmWOvD40sg= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=D1lcqp3G; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf25.hostedemail.com: domain of song@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=song@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746206787; 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=hbcahI7wFdZDBZyC5w9sU4ssdyxYtjLb0rj/djnehC8=; b=lgdJsVP1wRT6fTgHdi2pFuAILexkeGRGCgrjJzw/NhQGKdR7oAxklaK+7312Vdyev/AyVY Y3fm+382zlsxJrPJUM12Is/lT+Uf1B8POZfSgsHzIch98TIfF6TYenB7K8iEgA27NP2yV8 SowIXHWEU04039vcCNGGvUSPMAMZ7FI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id DB1085C4105 for ; Fri, 2 May 2025 17:24:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE6D7C4CEF1 for ; Fri, 2 May 2025 17:26:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746206785; bh=hbcahI7wFdZDBZyC5w9sU4ssdyxYtjLb0rj/djnehC8=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=D1lcqp3Gjvt6sCLzWAy20Mo5aGxNqjqqb+AjVH8aalQIuRKYDg2SOfCZua7xayTzh fbNx3aK2btW8eS4fMZruEPdeKjxZNUl5FKlLPO1TRvbegIu9myO7oX+hmmNM4VEbZq 5N7kgVU29bn8kIWa006Lz/+erbBN2e10xyq/O3p0Rkt9cCCoFbFBdQlSbcCc2C7lp+ Jt5e/0rDLbM4Ufvf0exiRrRKzAWXBn/xax5bbscyO9oCXkE/cGOINaiO4D49GfHDxR 0p+btKYjifTXixVRazK8TdBq4C+p2tNiBf6Ild1+DYb6BxH80K3q2JxAtz+sIyPI+r aZqgwhcoRr49w== Received: by mail-qv1-f54.google.com with SMTP id 6a1803df08f44-6e8f7019422so24533706d6.1 for ; Fri, 02 May 2025 10:26:25 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCVmjELy42uP3lc3Md+qndwfUWgra8nJK7hs70fQyKp/pnb/evF6NGD/IYm92iPAF6gHNQsKisGJOg==@kvack.org X-Gm-Message-State: AOJu0YwswJavUtDglQS9hNTRGKJ4tJUFc+2vr2kk2lnZ3NFioVINX/R2 Kdvpteeov/fSm6pZYh3wb5RAQShzgm13fTKFfELZXkYa45EwAgPZZT3eQdgJvkYmCx/nvGj8772 J80+wsTy9O+ichuDGsrlCX0BQIJo= X-Google-Smtp-Source: AGHT+IEhZx5zD8yvmvEs2lwLC7jhdDHIub8F3jphQG6t+/Qcqbn4ET6dyyzb12UcrVhVjjlh/VUhyhTnZS1toMBam58= X-Received: by 2002:a05:6214:19c5:b0:6e8:c713:321f with SMTP id 6a1803df08f44-6f515619481mr67835656d6.35.1746206784870; Fri, 02 May 2025 10:26:24 -0700 (PDT) MIME-Version: 1.0 References: <20250428033617.3797686-1-roman.gushchin@linux.dev> In-Reply-To: From: Song Liu Date: Fri, 2 May 2025 10:26:13 -0700 X-Gmail-Original-Message-ID: X-Gm-Features: ATxdqUFRV-jbWynKud--5JYm-b1VhDwA684cpaHQle-nRCzMtQq6Bv3ULYdoS7s Message-ID: Subject: Re: [PATCH rfc 00/12] mm: BPF OOM To: Kumar Kartikeya Dwivedi Cc: Roman Gushchin , Matt Bobrowski , linux-kernel@vger.kernel.org, Andrew Morton , Alexei Starovoitov , Johannes Weiner , Michal Hocko , Shakeel Butt , Suren Baghdasaryan , David Rientjes , Josh Don , Chuyi Zhou , cgroups@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 2A4CEA000C X-Stat-Signature: 81u8p761btkrpruibffotnnk5y8uaj8y X-Rspam-User: X-HE-Tag: 1746206786-251556 X-HE-Meta: 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 tbDCIJ75 J46/3zq11uZyaF4TwR1jc34wP9N1d0jdU6FifyHTKjPed3Tfc1PHcYorcIbzde3TdZi7MgsxUTsnQSdTL28wb4fWmTDwQt7cxTAN0r9I9U5Uu6F/fM3fCakVICimlK5HbZtNtWxWSp85JM+F9zWJatJ8E+onKm5q5Oi9FB1y+wCyzL9Xkk4OzmaO/J/664nQ3qQ+Yzt2neIj0Cwy6uOL7pOTd7NiRnstQCxi0kDDmXbNTqoQIRY+p9Tv/WR70+6tL6kLxaqOvsev8X67oTUuScyLuefKugpDj/az9EhHTS5n5VrHl4Titzh734Q== 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 Mon, Apr 28, 2025 at 6:57=E2=80=AFPM Kumar Kartikeya Dwivedi wrote: [...] > > > > It's certainly an option and I thought about it. I don't think we need = a bunch > > of hooks though. This patchset adds 2 and they belong to completely dif= ferent > > subsystems (mm and sched/psi), so Idk how well they can be gathered > > into a single struct ops. But maybe it's fine. > > > > The only potentially new hook I can envision now is one to customize > > the oom reporting. > > > > If you're considering scoping it down to a particular cgroup (as you > allude to in the TODO), or building a hierarchical interface, using > struct_ops will be much better than fmod_ret etc., which is global in > nature. Even if you don't support it now. I don't think a struct_ops > is warranted only when you have more than a few callbacks. As an > illustration, sched_ext started out without supporting hierarchical > attachment, but will piggy-back on the struct_ops interface to do so > in the near future. +1 for using struct_ops, which is the best way to enable BPF in existing use cases. Song