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 93930389118; Sat, 17 Oct 2026 16:15:24 +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=1792253725; cv=none; b=nwKRljT3BTQMMZzuzuuJSVQ3r0aUsNG7i+FPYDhp3MpdLkxuXaHafo+qB6y6PXcX7MC0oN5q/YAAhyrIq8FfFdJ3mAZjlPawSs8PjjAmPHzj4iImM0BNlq92/hV5UmWYkZzpxZDUJaOq/lzq7oK3epACkGEggScBMM+M9SfOEO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792253725; c=relaxed/simple; bh=VZI0ER4wyTniFWkcopeSB/ADI+VE/CWl13wohg25CKE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WglHexsDNwvRIQ9k7X+QCUKCvpYyXQEKe08fuOScSzgUGbaWfBw8cBEGtUTnbytYQ3twEQKc6j2xRYY/yBkLt1LHzkrfoG7qP2YDOSaDnMQysznD8zZuR4ue4Hu+qSeP6//oLyulXH2S/GgEe8JMWkG3mINt8m5c//ZHwMllj70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sNMwpR+u; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sNMwpR+u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B30F21F000C4; Sat, 17 Oct 2026 16:15:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792253724; bh=UaO/y/oZgl5Jo9snrYAjvRiJMHbCa3Z/Ib/aHOOlt0U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sNMwpR+uiaD8Fj3eMEiFkxefo4srJFqKhlMtYNcVFZSUh7NqLa/+tVcc9KMQ0qNDj n8kf67sCN85s+hLJsuOi88fYJ2X+kroNu6T26W/1661A0J5pB+oIxOtrVv7+5ZPiZD jIXesuNzQ6Kzr/GVy3Gv3kThPt9HKQVNkyk8FpAc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 213/869] mptcp: cleanup mem accounting Date: Sat, 17 Oct 2026 17:50:54 +0200 Message-ID: <20261017160042.514469539@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160036.979869304@linuxfoundation.org> References: <20261017160036.979869304@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 6639498ed85fdb135dfb0dfbcc0f540b2d4ad6a6 ] After the previous patch, updating sk_forward_memory is cheap and we can drop a lot of complexity from the MPTCP memory accounting, removing the custom fwd mem allocations for rmem. Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-4-4a47d90d7998@kernel.org Signed-off-by: Jakub Kicinski Stable-dep-of: 5dd8025a49c2 ("mptcp: fix soft lockup in mptcp_recvmsg()") Signed-off-by: Sasha Levin --- net/mptcp/fastopen.c | 2 +- net/mptcp/protocol.c | 115 +++---------------------------------------- net/mptcp/protocol.h | 4 +- 3 files changed, 10 insertions(+), 111 deletions(-) diff --git a/net/mptcp/fastopen.c b/net/mptcp/fastopen.c index 40ca9aa21a626..3db79f3a52bac 100644 --- a/net/mptcp/fastopen.c +++ b/net/mptcp/fastopen.c @@ -53,7 +53,7 @@ void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subf mptcp_data_lock(sk); DEBUG_NET_WARN_ON_ONCE(sock_owned_by_user_nocheck(sk)); - mptcp_set_owner_r(skb, sk); + skb_set_owner_r(skb, sk); __skb_queue_tail(&sk->sk_receive_queue, skb); mptcp_sk(sk)->bytes_received += skb->len; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 6106c561026d6..5e094c72dcbb7 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -141,17 +141,6 @@ static void mptcp_drop(struct sock *sk, struct sk_buff *skb) __kfree_skb(skb); } -static void mptcp_rmem_fwd_alloc_add(struct sock *sk, int size) -{ - WRITE_ONCE(mptcp_sk(sk)->rmem_fwd_alloc, - mptcp_sk(sk)->rmem_fwd_alloc + size); -} - -static void mptcp_rmem_charge(struct sock *sk, int size) -{ - mptcp_rmem_fwd_alloc_add(sk, -size); -} - static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, struct sk_buff *from) { @@ -174,7 +163,7 @@ static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, * negative one */ atomic_add(delta, &sk->sk_rmem_alloc); - mptcp_rmem_charge(sk, delta); + sk_mem_charge(sk, delta); kfree_skb_partial(from, fragstolen); return true; @@ -189,44 +178,6 @@ static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to, return mptcp_try_coalesce((struct sock *)msk, to, from); } -static void __mptcp_rmem_reclaim(struct sock *sk, int amount) -{ - amount >>= PAGE_SHIFT; - mptcp_rmem_charge(sk, amount << PAGE_SHIFT); - __sk_mem_reduce_allocated(sk, amount); -} - -static void mptcp_rmem_uncharge(struct sock *sk, int size) -{ - struct mptcp_sock *msk = mptcp_sk(sk); - int reclaimable; - - mptcp_rmem_fwd_alloc_add(sk, size); - reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk); - - /* see sk_mem_uncharge() for the rationale behind the following schema */ - if (unlikely(reclaimable >= PAGE_SIZE)) - __mptcp_rmem_reclaim(sk, reclaimable); -} - -static void mptcp_rfree(struct sk_buff *skb) -{ - unsigned int len = skb->truesize; - struct sock *sk = skb->sk; - - atomic_sub(len, &sk->sk_rmem_alloc); - mptcp_rmem_uncharge(sk, len); -} - -void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk) -{ - skb_orphan(skb); - skb->sk = sk; - skb->destructor = mptcp_rfree; - atomic_add(skb->truesize, &sk->sk_rmem_alloc); - mptcp_rmem_charge(sk, skb->truesize); -} - /* "inspired" by tcp_data_queue_ofo(), main differences: * - use mptcp seqs * - don't cope with sacks @@ -339,25 +290,7 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) end: skb_condense(skb); - mptcp_set_owner_r(skb, sk); -} - -static bool mptcp_rmem_schedule(struct sock *sk, int size) -{ - struct mptcp_sock *msk = mptcp_sk(sk); - int amt, amount; - - if (size <= msk->rmem_fwd_alloc) - return true; - - size -= msk->rmem_fwd_alloc; - amt = sk_mem_pages(size); - amount = amt << PAGE_SHIFT; - if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) - return false; - - mptcp_rmem_fwd_alloc_add(sk, amount); - return true; + skb_set_owner_r(skb, sk); } static void mptcp_init_skb(struct sock *ssk, struct sk_buff *skb, int offset, @@ -389,7 +322,7 @@ static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb) struct sk_buff *tail; /* try to fetch required memory from subflow */ - if (!mptcp_rmem_schedule(sk, skb->truesize)) { + if (!sk_rmem_schedule(sk, skb, skb->truesize)) { MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); mptcp_drop(sk, skb); return false; @@ -403,7 +336,7 @@ static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb) if (tail && mptcp_try_coalesce(sk, tail, skb)) return true; - mptcp_set_owner_r(skb, sk); + skb_set_owner_r(skb, sk); __skb_queue_tail(&sk->sk_receive_queue, skb); return true; } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) { @@ -2087,9 +2020,10 @@ static int __mptcp_recvmsg_mskq(struct sock *sk, break; } - /* we will bulk release the skb memory later */ + /* avoid the indirect call, we know the destructor is sock_wfree */ skb->destructor = NULL; - WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize); + atomic_sub(skb->truesize, &sk->sk_rmem_alloc); + sk_mem_uncharge(sk, skb->truesize); __skb_unlink(skb, &sk->sk_receive_queue); __kfree_skb(skb); } @@ -2202,18 +2136,6 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) msk->rcvq_space.time = mstamp; } -static void __mptcp_update_rmem(struct sock *sk) -{ - struct mptcp_sock *msk = mptcp_sk(sk); - - if (!msk->rmem_released) - return; - - atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc); - mptcp_rmem_uncharge(sk, msk->rmem_released); - WRITE_ONCE(msk->rmem_released, 0); -} - static bool __mptcp_move_skbs(struct sock *sk) { struct mptcp_subflow_context *subflow; @@ -2237,7 +2159,6 @@ static bool __mptcp_move_skbs(struct sock *sk) break; slowpath = lock_sock_fast(ssk); - __mptcp_update_rmem(sk); done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); if (unlikely(ssk->sk_err)) @@ -2245,12 +2166,7 @@ static bool __mptcp_move_skbs(struct sock *sk) unlock_sock_fast(ssk, slowpath); } while (!done); - ret = moved > 0; - if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || - !skb_queue_empty(&sk->sk_receive_queue)) { - __mptcp_update_rmem(sk); - ret |= __mptcp_ofo_queue(msk); - } + ret = moved > 0 || __mptcp_ofo_queue(msk); if (ret) mptcp_check_data_fin((struct sock *)msk); @@ -2974,8 +2890,6 @@ static void __mptcp_init_sock(struct sock *sk) INIT_WORK(&msk->work, mptcp_worker); msk->out_of_order_queue = RB_ROOT; msk->first_pending = NULL; - WRITE_ONCE(msk->rmem_fwd_alloc, 0); - WRITE_ONCE(msk->rmem_released, 0); msk->timer_ival = TCP_RTO_MIN; msk->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; @@ -3205,8 +3119,6 @@ static void __mptcp_destroy_sock(struct sock *sk) sk->sk_prot->destroy(sk); - WARN_ON_ONCE(READ_ONCE(msk->rmem_fwd_alloc)); - WARN_ON_ONCE(msk->rmem_released); sk_stream_kill_queues(sk); xfrm_sk_free_policy(sk); @@ -3586,8 +3498,6 @@ void mptcp_destroy_common(struct mptcp_sock *msk) /* move all the rx fwd alloc into the sk_mem_reclaim_final in * inet_sock_destruct() will dispose it */ - sk_forward_alloc_add(sk, msk->rmem_fwd_alloc); - WRITE_ONCE(msk->rmem_fwd_alloc, 0); mptcp_token_destroy(msk); spin_lock_bh(&msk->pm.lock); @@ -3689,8 +3599,6 @@ static void mptcp_release_cb(struct sock *sk) if (__test_and_clear_bit(MPTCP_SYNC_SNDBUF, &msk->cb_flags)) __mptcp_sync_sndbuf(sk); } - - __mptcp_update_rmem(sk); } /* MP_JOIN client subflow must wait for 4th ack before sending any data: @@ -3868,12 +3776,6 @@ static void mptcp_shutdown(struct sock *sk, int how) __mptcp_wr_shutdown(sk); } -static int mptcp_forward_alloc_get(const struct sock *sk) -{ - return READ_ONCE(sk->sk_forward_alloc) + - READ_ONCE(mptcp_sk(sk)->rmem_fwd_alloc); -} - static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v) { const struct sock *sk = (void *)msk; @@ -4032,7 +3934,6 @@ static struct proto mptcp_prot = { .hash = mptcp_hash, .unhash = mptcp_unhash, .get_port = mptcp_get_port, - .forward_alloc_get = mptcp_forward_alloc_get, .stream_memory_free = mptcp_stream_memory_free, .sockets_allocated = &mptcp_sockets_allocated, diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 2f298250d575c..f3955c06be671 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -284,7 +284,6 @@ struct mptcp_sock { u64 rcv_data_fin_seq; u64 bytes_retrans; u64 bytes_consumed; - int rmem_fwd_alloc; int snd_burst; int old_wspace; u64 recovery_snd_nxt; /* in recovery mode accept up to this seq; @@ -299,7 +298,6 @@ struct mptcp_sock { u32 last_ack_recv; unsigned long timer_ival; u32 token; - int rmem_released; unsigned long flags; unsigned long cb_flags; bool recovery; /* closing subflow write queue reinjected */ @@ -397,7 +395,7 @@ static inline void msk_owned_by_me(const struct mptcp_sock *msk) */ static inline int __mptcp_rmem(const struct sock *sk) { - return atomic_read(&sk->sk_rmem_alloc) - READ_ONCE(mptcp_sk(sk)->rmem_released); + return atomic_read(&sk->sk_rmem_alloc); } static inline int mptcp_win_from_space(const struct sock *sk, int space) -- 2.53.0