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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B61ECCA1002 for ; Thu, 4 Sep 2025 14:32:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 11F978E000B; Thu, 4 Sep 2025 10:32:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0F79C8E0001; Thu, 4 Sep 2025 10:32:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 00CA58E000B; Thu, 4 Sep 2025 10:32:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E825F8E0001 for ; Thu, 4 Sep 2025 10:32:26 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 7429357B6A for ; Thu, 4 Sep 2025 14:32:26 +0000 (UTC) X-FDA: 83851808292.06.BF0FE3C Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) by imf17.hostedemail.com (Postfix) with ESMTP id 7C3F94001D for ; Thu, 4 Sep 2025 14:32:24 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=xLHA9PwT; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 95.215.58.182 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756996344; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=HDBdIXqGhXisdI9dGc4nJcjo34W6QqppuoGXLGaIWNs=; b=LtWD8GBAqVG3tTI4eWZ7Lmn5fBdgfWd5QJeAoW9qpkhpSlKuCbpmWg5g7a2F7hhVMA3FB3 sGLNLEqwOqclzIWV0qMhVJ045dwuHA08x/uzdPssMl25xTUZX7C0LUp5Yb4AbB17art/8H FomqJrErYZ7s9fwlLOg5JVjXeeCOb2c= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=xLHA9PwT; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 95.215.58.182 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756996344; a=rsa-sha256; cv=none; b=uUtCEaGY12qy0uccZmaFgd3IAvoRQrvBpBUOSUBHGcF/UHyiuo823njnXIZTTVWGliXmc2 1CwtJuu4J4DpDXQaIls18zgwJQ+Yznx06Hre4x3HvVIGYl1CMqUSw2UcWTLUu3WKnrZ0wz qGzS2X/5Us0DtvfnCUnPYgYWIkSzNMs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1756996342; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HDBdIXqGhXisdI9dGc4nJcjo34W6QqppuoGXLGaIWNs=; b=xLHA9PwTaXoDBP744wDjpvRy1G72Zi59tr/7Y5cji3JaVm31+i7+3GsunlrLWew29Q06wB pqQesQNb4k0tq/5fkOp6hNSUTdaj4z1zkNydhaw46Myh/YE15jmwtN5elShJvFGRZSSzWZ pkh2e+M3ejdcOqenmCq4q5Z2ZDcIqEc= From: Roman Gushchin To: Tejun Heo Cc: Alexei Starovoitov , Martin KaFai Lau , Kumar Kartikeya Dwivedi , linux-mm , bpf , Suren Baghdasaryan , Johannes Weiner , Michal Hocko , David Rientjes , Matt Bobrowski , Song Liu , Alexei Starovoitov , Andrew Morton , LKML Subject: Re: [PATCH v1 01/14] mm: introduce bpf struct ops for OOM handling In-Reply-To: (Tejun Heo's message of "Wed, 3 Sep 2025 20:39:18 -1000") References: <20250818170136.209169-2-roman.gushchin@linux.dev> <87ms7tldwo.fsf@linux.dev> <1f2711b1-d809-4063-804b-7b2a3c8d933e@linux.dev> <87wm6rwd4d.fsf@linux.dev> <87iki0n4lm.fsf@linux.dev> <87qzwnxgfr.fsf@linux.dev> Date: Thu, 04 Sep 2025 07:32:14 -0700 Message-ID: <87h5xi1e6p.fsf@linux.dev> MIME-Version: 1.0 Content-Type: text/plain X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 7C3F94001D X-Stat-Signature: goo1sa5m7166rhtar3e85n3g31k66o1h X-Rspam-User: X-HE-Tag: 1756996344-972723 X-HE-Meta: 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 B4v57sxG Mp7/YgQn4K722oBI0TFWXfJHgasIGl821IpaL/uBBOw3+JMb4rb06uUgKXhQBhyk2/8zOHiLqKybLCiNiiFTOkLqjSpagoZyQ1xwgeeM3y117B3io60dWPRxmHCRrVpUd2TCOfXizkls52uVw4cirXb4XjlCstTKbLltkTI1fCgwLYC9cjFKsgb19YggmU8ga/jmGgIA9g0Er2dtdr7tUOPaYHlDHc9k8PuAI9SvfcI5JuCxQQLdBTFcimRYzKtSLVaRH 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: Tejun Heo writes: > Hello, > > On Wed, Sep 03, 2025 at 04:30:16PM -0700, Roman Gushchin wrote: > ... >> > - I'm passing in cgroup_id as an optional field in struct_ops and then in >> > enable path, look up the matching cgroup, verify it can attach there and >> > insert and update data structures accordingly: >> > >> > https://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git/tree/kernel/sched/ext.c?h=scx-hier-prototype#n5280 >> >> Yeah, we discussed this option with Martin up in this thread. It doesn't >> look as the best possible solution, but maybe the best we have at the moment. >> >> Ideally, I want something like this: >> >> void test_oom(void) >> { >> struct test_oom *skel; >> int err, cgroup_fd; >> >> cgroup_fd = open(...); >> if (cgroup_fd < 0) >> goto cleanup; >> >> skel = test_oom__open_and_load(); >> if (!skel) >> goto cleanup; >> >> err = test_oom__attach_cgroup(skel, cgroup_fd); >> if (CHECK_FAIL(err)) >> goto cleanup; > > Yeah, that'd look better but are there practical differences? The only one I > can think of is fs based permission check but that can be done separately > too. The practical difference is that a single struct ops can be attached to multiple cgroups.