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 EE8A4CCF9EB for ; Wed, 29 Oct 2025 20:28:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 610D48E00F6; Wed, 29 Oct 2025 16:27:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5C1748E00B2; Wed, 29 Oct 2025 16:27:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D77B8E00F6; Wed, 29 Oct 2025 16:27:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 381D18E00B2 for ; Wed, 29 Oct 2025 16:27:13 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id AA74989020 for ; Wed, 29 Oct 2025 20:27:12 +0000 (UTC) X-FDA: 84052286304.11.CBBD87F Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) by imf17.hostedemail.com (Postfix) with ESMTP id D1F7240010 for ; Wed, 29 Oct 2025 20:27:10 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=uDvBTjFN; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 91.218.175.172 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1761769631; a=rsa-sha256; cv=none; b=YJDLU+YuNkbd8sRFPh1oGE/mQjnrKZ3QEXyNz/p32DOwqFxqmsxSFTWG+OtWkryFqVndFm +mMcCcOWNOe4G07dTemqr/tBl9QTiCuPB/U9ONJDIaMEL6ENpsHJqRnLjAh/zEYMOvrAjz 1OPuYyo5JF7IKqjzaivKJNBMTY7L3a4= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=uDvBTjFN; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 91.218.175.172 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=1761769631; 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=L5vmLW+oATPFNaWdtHY1yVME8el6pZeETE8QCtK8TCA=; b=hSWPFl3tSN11DAx5akH2W5stFR+eBWK0rQGBR236FnqDBzriplkhmgBPhH1HJ0rJxIjsQR 2MyYj/+7bg6fKqePt+RawW7z4BNT8Zps6nfZrJ1mzqto3SFFQMD3mG9nZfF+SQ7wFPRsgJ 9pgqlWlz9jqf1L5ciJmxuMN2bMZqmNk= 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=1761769626; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=L5vmLW+oATPFNaWdtHY1yVME8el6pZeETE8QCtK8TCA=; b=uDvBTjFNloStyK5QFb/yoXxdR2x9MXtvvx+VlwjlfcjJkJJCF/u4jP8Z1O8uvzIJVQei7i DLMoZGz0HxN1qz2OYh0rxnJZijSp4ZzRT5ISRcNxuFsImqMhMXzbscUzEIQ+vEupnezkGS jrYIMHJUDg0Es/IWmxMEqmpTQ0M5jVI= From: Roman Gushchin To: Song Liu Cc: Andrew Morton , linux-kernel@vger.kernel.org, Alexei Starovoitov , Suren Baghdasaryan , Michal Hocko , Shakeel Butt , Johannes Weiner , Andrii Nakryiko , JP Kobryn , linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Kumar Kartikeya Dwivedi , Tejun Heo Subject: Re: [PATCH v2 02/23] bpf: initial support for attaching struct ops to cgroups In-Reply-To: (Song Liu's message of "Wed, 29 Oct 2025 11:01:00 -0700") References: <20251027231727.472628-1-roman.gushchin@linux.dev> <20251027231727.472628-3-roman.gushchin@linux.dev> Date: Wed, 29 Oct 2025 13:26:59 -0700 Message-ID: <87cy65e9nw.fsf@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D1F7240010 X-Stat-Signature: 5ikowjjd6bqnpijzds1sjtxoqn8rhtkg X-HE-Tag: 1761769630-937292 X-HE-Meta: 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 x5ut/16q fVv4pmA5IHPu8G5xEDyp3HtRnxigOqPYX9jtr0k1RELKHAds5oqy22zE/Eam6A3VEr13tt90BzddZahwXKEqDtM3OZUa9QuXIhdUid6Sb3zoO8k71w4qEeEaOz7B2GwJSYECQgLHm6amJbT5KI8bO6D85Al6TdwDZrGf5XulgKGbcF7nJC+a3X+6WRxeX3KqFJ9pnu/ZD5+GFMukfTyGjbsyUr87wETgK7ptzEkAXqmo+o50= 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: Song Liu writes: > On Mon, Oct 27, 2025 at 4:17=E2=80=AFPM Roman Gushchin wrote: > [...] >> struct bpf_struct_ops_value { >> struct bpf_struct_ops_common_value common; >> @@ -1359,6 +1360,18 @@ int bpf_struct_ops_link_create(union bpf_attr *at= tr) >> } >> bpf_link_init(&link->link, BPF_LINK_TYPE_STRUCT_OPS, &bpf_struct= _ops_map_lops, NULL, >> attr->link_create.attach_type); >> +#ifdef CONFIG_CGROUPS >> + if (attr->link_create.cgroup.relative_fd) { >> + struct cgroup *cgrp; >> + >> + cgrp =3D cgroup_get_from_fd(attr->link_create.cgroup.rel= ative_fd); > > We should use "target_fd" here, not relative_fd. Ok, thanks! > > Also, 0 is a valid fd, so we cannot use target_fd =3D=3D 0 to attach to > global memcg. Yep, switching to using root_memcg's fd instead. Thanks!