From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B151614A0B5; Wed, 13 Aug 2025 08:54:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755075269; cv=none; b=gvpxJVqyAYewJZSX+vl5Ghc1mrq7maUyq9iUOzZRJFnJlcWPK+ge3Pux9e4m2BvXTvFmM16vo73xmVmpJylGOUyG3idBfYnjeWxqHueWHEFFeDA9PjCAcmVkgD5hW0lhoX+vC6ssm+jfLMn3iR15aZzaVEzlmhfkpS3DLKxAL2Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755075269; c=relaxed/simple; bh=SPEB5tXelaltjOYbgqCSrRrEOItBWpxIPqLytrMKnXI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=d0w7V2A3TZufv/T1BANVZNcfiRBKoO1zpD7heh3OSPPkCq/6/gFIVnQcL7xHZZG6tFlVbNEqF182xU5QiP4wAtUZSjqOvrAAONPobFp72sGInazHxvm+i62qLRBA6Q1V8B1HGsEUOybu2nKMKLWwk5tDv5bjHGI0OryxGHfynOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=herhqNMS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="herhqNMS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 244F6C4CEEB; Wed, 13 Aug 2025 08:54:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755075269; bh=SPEB5tXelaltjOYbgqCSrRrEOItBWpxIPqLytrMKnXI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=herhqNMSZD2u105m3vJP0R5NGzYg8f4wgoRgW1wtPscJKKIJ8iB4LCJ7YZVRkLPll aCCq99Y1WcMsFRfF/bEfd1fSFHveJwvnInSPrmYXF2cRC2hyInkxWN8eQxpBsmUJ5V YYqJztfk0ZrC5Nj6PYyK0wR/z1CMA+zjyQ2L+rgakOM+7mxQpupCHI862M8uAUf95o 1nJMo9GRs6ivwlUcrBQSLXyiTO5gay4Ee2JPzyWsMsJY8m4R/U9q84az1GLtzRIh0K dVVBFh4NXq5IGdfu4xeKewoyKhGtZBzp+MrA515ppiDaVha4AKPsNTEq2kPm4+UDir r3hGyQdMGXGhw== Message-ID: <603e3360-1f8f-41bd-94fd-a4a94e4a2c34@kernel.org> Date: Wed, 13 Aug 2025 10:54:19 +0200 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH v3 net-next 01/12] mptcp: Fix up subflow's memcg when CONFIG_SOCK_CGROUP_DATA=n. Content-Language: en-GB, fr-BE To: Kuniyuki Iwashima , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Neal Cardwell , Paolo Abeni , Willem de Bruijn , Mat Martineau , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Andrew Morton , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Tejun Heo Cc: Simon Horman , Geliang Tang , Muchun Song , Mina Almasry , Kuniyuki Iwashima , netdev@vger.kernel.org, mptcp@lists.linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org References: <20250812175848.512446-1-kuniyu@google.com> <20250812175848.512446-2-kuniyu@google.com> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <20250812175848.512446-2-kuniyu@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Kuniyuki, On 12/08/2025 19:58, Kuniyuki Iwashima wrote: > When sk_alloc() allocates a socket, mem_cgroup_sk_alloc() sets > sk->sk_memcg based on the current task. > > MPTCP subflow socket creation is triggered from userspace or > an in-kernel worker. > > In the latter case, sk->sk_memcg is not what we want. So, we fix > it up from the parent socket's sk->sk_memcg in mptcp_attach_cgroup(). > > Although the code is placed under #ifdef CONFIG_MEMCG, it is buried > under #ifdef CONFIG_SOCK_CGROUP_DATA. > > The two configs are orthogonal. If CONFIG_MEMCG is enabled without > CONFIG_SOCK_CGROUP_DATA, the subflow's memory usage is not charged > correctly. > > Let's move the code out of the wrong ifdef guard. > > Note that sk->sk_memcg is freed in sk_prot_free() and the parent > sk holds the refcnt of memcg->css here, so we don't need to use > css_tryget(). Thank you for the patch! Acked-by: Matthieu Baerts (NGI0) Cheers, Matt -- Sponsored by the NGI0 Core fund.