From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2EF7C34D382; Wed, 23 Sep 2026 02:11:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790129478; cv=none; b=i8JHbEH3zwd4UFr5D/IdPmrPO7UERcQMr9mkdcV80XBqQRKyTnyKxFZ22pikVuGyzX8THB3grGkIOhkiiQc5Dl1L4nr2EP6+XwoaUdlSgXEGgAFMA82liX2zVWTT0hj+L6QdtIgDzbbALs3kuOj817XYmk2LW9pnxyMwM4wXWIw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790129478; c=relaxed/simple; bh=idgMeQkolLxrBKlHTfh0UDxVONy509qU1OR0hdN1pNw=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=CEKqlD/VdMZzrQJiZpqsMKTNhN70ehgsujEFhxBqPWhQDMRSG9iE+4sHu5nwOpUfuQo3YXCRlzDrX5FqO4pGqGfUBilLpwoBjyrF6T/Dc0ZKK61pqgmRR9Of3H/CcqOALZJORTerKRkuAKOfgr+l+aVHpKrdkAqIeQG0zSXx2gQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cVLP4OIj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cVLP4OIj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0F2A1F000FF; Wed, 23 Sep 2026 02:11:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790129476; bh=72o8XdeHOO0nvYEC27EwUle5PwfmgPHOTqUbse1xuP8=; h=Subject:From:Date:References:In-Reply-To:To:Cc; b=cVLP4OIjcQtBEQk4Kd7+/s85av0NOiwTscc85yH5tqVX7K142j5D8jaR0MXKkNq4a bwoYZYF7dmvafW82Uycjl3ljoT1WBIHz/mSyzY/qPwHSjy99EB4w4ycF1UTR0NP7Xi 0TaqE4VaywsWORTsYkAJo1FugkE1Dw+f3espJKC0f+1Q48bIFmLAqW7P3Ujtfn/9az gy3wRPtlQN37Oi923oZrlOUk6c+z+zymweTSXAlmgwr+pqW6VmHrQBhNC88m1ULN22 P30hTLlstZwRkWum1IRuMuzRR8iu9EXSHFE2fWPecCNYits1qR6qFAvy9szm4k1AAB O7HpRJvnPtHWg== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id 93A343924472; Wed, 23 Sep 2026 02:10:08 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH bpf-next v9 0/3] bpf: arena: handle memory.max on fault-in with reclaim From: patchwork-bot+netdevbpf@kernel.org Message-Id: <179012940739.177114.1298290865811499101.git-patchwork-notify@kernel.org> Date: Wed, 23 Sep 2026 02:10:07 +0000 References: <20260922101831.192102-1-jiayuan.chen@linux.dev> In-Reply-To: <20260922101831.192102-1-jiayuan.chen@linux.dev> To: Jiayuan Chen Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, emil@etsalapatis.com, ihor.solodrai@linux.dev, shuah@kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Hello: This series was applied to bpf/bpf-next.git (master) by Alexei Starovoitov : On Tue, 22 Sep 2026 18:17:32 +0800 you wrote: > Since commit e66fe1bc6d25 ("bpf: arena: Reintroduce memcg accounting"), > arena pages are charged to the memcg of the process that created the arena. > That exposes a problem in the arena user page fault path: the fault-in > allocation runs under arena->spinlock, so it can only use the non-blocking > allocator, which never reclaims. Once memory.current is at memory.max the > allocation simply fails, even when the memcg is full of page cache that > could be dropped right away. Reaching memory.max is completely normal for a > healthy application - e.g. reading a large file fills memory.current with > page cache - and the process then gets SIGSEGV on a perfectly valid arena > address. > > [...] Here is the summary with links: - [bpf-next,v9,1/3] bpf: arena: allocate the fault-in page outside the lock https://git.kernel.org/bpf/bpf-next/c/c7cd8be3d72f - [bpf-next,v9,2/3] selftests/bpf: Add read_cgroup_file() to cgroup_helpers https://git.kernel.org/bpf/bpf-next/c/a781db31b484 - [bpf-next,v9,3/3] selftests/bpf: Add a test for arena fault-in under memory.max https://git.kernel.org/bpf/bpf-next/c/1fe5a5cd01e4 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html