From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EA5C27702A for ; Tue, 2 Sep 2025 23:36:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756856209; cv=none; b=R9pRvC9ZJZy++kJ4ZxmbnKT7L42IJghFUJvPGaH3t+CyNxp1lAbMfgiWGphzLUm4hSUKL8L4/yg6JlpBkXvTKyBmHI12CwMlUia7JvyVcFwgTGBdbpV6KwB6kKgMNFrUZCDh1j3XSb9ka0LhfCUYP0papCIgBTIa2S5HRkq3hFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756856209; c=relaxed/simple; bh=4VRotmPacgDSBhrhKHEwQvLwXAIZ2QzWSVjur4ooG6I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ISEuPx22nWCe+HTVtnuL7fQGyYbC6lbGpdYjJvxvMIc9fTFqinaw5NyEzW/z1vEYCtz2kRXLIf2rGeBJ23ZA9dfgm26YnUGj6+Uv/OgwBOjf6/hCGs+jNK2pjFKco1lWrYrhb3CRJPpnO6W1y7j4sSatN/4WcfW4UbHtS6E4rHE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=d7+z3KRj; arc=none smtp.client-ip=91.218.175.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="d7+z3KRj" 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=1756856195; 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=4VRotmPacgDSBhrhKHEwQvLwXAIZ2QzWSVjur4ooG6I=; b=d7+z3KRjKnYgIE8FVboMNcu7cNJ22o0DwNdthxu9cPcAnsobQBApJF/8cftXd51mtBvxBk oNje22SYw/0i4sNoY4RKXd8pZxN4Yo2xT3ys5FFmFFvr41PRc8X6zPCH6lHOGwVv0PBKtI CL58h7dU/uh1AGcCuCtqP1r4DrEqgQE= From: Roman Gushchin To: Martin KaFai Lau Cc: Alexei Starovoitov , 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: (Martin KaFai Lau's message of "Tue, 2 Sep 2025 15:30:04 -0700") References: <20250818170136.209169-1-roman.gushchin@linux.dev> <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> Date: Tue, 02 Sep 2025 16:36:27 -0700 Message-ID: <87ms7c5sw4.fsf@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Migadu-Flow: FLOW_OUT Martin KaFai Lau writes: > On 9/2/25 10:31 AM, Roman Gushchin wrote: >> Btw, what's the right way to attach struct ops to a cgroup, if there is >> one? Add a cgroup_id field to the struct and use it in the .reg() > > Adding a cgroup id/fd field to the struct bpf_oom_ops will be hard to > attach the same bpf_oom_ops to multiple cgroups. Yeah, this is what I thought too, it doesn't look as an attractive path. > >> callback? Or there is something better? > > There is a link_create.target_fd in the "union bpf_attr". The > cgroup_bpf_link_attach() is using it as cgroup fd. May be it can be > used here also. This will limit it to link attach only. Meaning the > SEC(".struct_ops.link") is supported but not the older > SEC(".struct_ops"). I think this should be fine. I'll take a look, thank you!