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 59A3F2C0F6C for ; Wed, 12 Nov 2025 09:55:58 +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=1762941358; cv=none; b=k8Erw9oOzNKbcldWQVnHyPVygzHizC6i2NHEcYIX61pTLxZCAaYBCt0QVzv/3pzfgcpAcjH0Nr4GYXIZ3p0IxMJSF9A+o0a8Es3GXY4v/RQb0N28DtXIdpkwWSTDjbHqHZW8bwdTgaz3irlf2qX0MXnUUKiQuB9EHtJ7ulK1n7k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762941358; c=relaxed/simple; bh=Awv3Nez6OR4q98NhFgvg1vYbGW9PlpMQBhv0l/50468=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OApvk6bwg6LnKQdxTjZ4BZNEhuyYxn5Xl/1DDZJreDVOQyP8wRYOk3iswhSY63mPn5GzPaSsYbuGnd79V6WU+HwI1UPjFF0vzGtrbcs/ESXvRQ44BpFER7E+WUnax1zVdOu+xUMz15NHx97fjf4fsKneQ1vSKsi75OlpX+2XT/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BUnhPT+Y; 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="BUnhPT+Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 564D8C4CEF8; Wed, 12 Nov 2025 09:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762941357; bh=Awv3Nez6OR4q98NhFgvg1vYbGW9PlpMQBhv0l/50468=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=BUnhPT+YiLNkV6dQLg6U+u/+VovAtr9e/4SyqZXipaIXNdA4evclW5G4UK58PT7Oj dA36BbcIcQol/hKFhdZoU+TGHK+WxGozBM3OCI1ZcBN5+2mW0tGcI3+6Lr3FdOT/UX AWxUHe0ndcQxpf98t4eb+H6u/GmAyB9sKzznjMNfkE5jD5iyGvkEJBxgv8VLvmu6hQ VpyuEArsEkaOhsDN4lVgfwjSqdZlCxwr2gUrruBSEyRLmcNcb3I0yagcmacA0ylvcb l5+7pc7jES2Hgqg/Lphai8vdzP0h8L4h9BAzUiCiY7eyA6QYq9KMGtuGM5le12JyXb K2q8uKYarcwVA== Message-ID: <0db0481f-9611-4d86-a291-4606004c4067@kernel.org> Date: Wed, 12 Nov 2025 10:55:55 +0100 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp-net 1/3] net: factor-out _sk_charge() helper Content-Language: en-GB, fr-BE To: Paolo Abeni Cc: mptcp@lists.linux.dev References: <063e2bc8e98ce050286eb4309bf4bd47716cc3f8.1762551942.git.pabeni@redhat.com> <63928360-2947-49d7-8e8e-9f83745f3556@redhat.com> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/11/2025 10:28, Paolo Abeni wrote: > On 11/12/25 10:16 AM, Matthieu Baerts wrote: >> On 12/11/2025 10:04, Paolo Abeni wrote: >>> >>> On 11/11/25 6:38 PM, Matthieu Baerts wrote: >>>> On 07/11/2025 22:55, Paolo Abeni wrote: >>>>> Move out of __inet_accept() the code dealing charging newly >>>>> accepted socket to memcg. MPTCP will soon use it to on a per >>>>> subflow basis, in different contexts. >>>>> >>>>> No functional changes intended. >> >> (...) >> >>>>> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c >>>>> index a31b94ce8968..08d811f11896 100644 >>>>> --- a/net/ipv4/af_inet.c >>>>> +++ b/net/ipv4/af_inet.c >>>>> @@ -756,23 +756,8 @@ EXPORT_SYMBOL(inet_stream_connect); >>>>> void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk) >>>>> { >>>>> if (mem_cgroup_sockets_enabled) { >>>>> - gfp_t gfp = GFP_KERNEL | __GFP_NOFAIL; >>>>> - >>>>> mem_cgroup_sk_alloc(newsk); >>>>> - >>>>> - if (mem_cgroup_from_sk(newsk)) { >>>>> - int amt; >>>>> - >>>>> - /* The socket has not been accepted yet, no need >>>>> - * to look at newsk->sk_wmem_queued. >>>>> - */ >>>>> - amt = sk_mem_pages(newsk->sk_forward_alloc + >>>>> - atomic_read(&newsk->sk_rmem_alloc)); >>>>> - if (amt) >>>>> - mem_cgroup_sk_charge(newsk, amt, gfp); >>>>> - } >>>>> - >>>>> - kmem_cache_charge(newsk, gfp); >>>> >>>> Mmh, this code has been moved from inet_csk_accept() to __inet_accept() >>>> in net-next only, see commit 4a997d49d92a ("tcp: Save lock_sock() for >>>> memcg in inet_csk_accept()."): >>>> >>>> https://lore.kernel.org/20251014235604.3057003-2-kuniyu@google.com >>> >>> Right you are! >>> >>>> Should we only apply these patches in our export branch, for net-next? >>>> If yes, then I guess we should remove the Fixes tag in patch 3/3. >>> >>> Technically is a fix. Even prior to the backlog introduction bad thing >>> could happen, as passive msk does not have memory by the subflow only >>> accounted. >>> >>> TCP-level OoO could potentially use a lot of system memory that will not >>> be memaccounted. >>> >>> Unfortunately it's not easy to have a clean net patch. >>> >>> I suppose with can have this as net-next fixes (including the fixes tag >>> in 3/3) as the change is invasive and the thing is broken since the >>> beginning. >>> >>> WDYT? >> >> It sounds good to me. When these patches will be in Linus tree, we can >> ask to backport these 3 patches from this series, plus commit >> 4a997d49d92a ("tcp: Save lock_sock() for memcg in inet_csk_accept()."), no? >> >> If yes, do you think I can add a "Cc: stable", and explaining in the >> comments that it is because it depends on a patch that is only in >> net-next, and the fix is not urgent? > > You know I don't have all the fascination for stable;) I forgot :) > My first take > would be to avoid such tag. If you are willing to do the extra mile I > guess that is a good plan. Alternatively you could just send the patch > to stable after merge, with pre-req included. Adding the "Cc: stable" allow me to forget about backporting it, except if there are conflicts! But I can add a reminder :) Cheers, Matt -- Sponsored by the NGI0 Core fund.