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[108.212.132.20]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-4177e6ae0e3sm1568938fac.16.2026.03.11.00.56.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Mar 2026 00:56:38 -0700 (PDT) From: Wesley Atwell To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, ncardwell@google.com, dsahern@kernel.org, matttbe@kernel.org, martineau@kernel.org, netdev@vger.kernel.org, mptcp@lists.linux.dev Cc: kuniyu@google.com, horms@kernel.org, geliang@kernel.org, corbet@lwn.net, skhan@linuxfoundation.org, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, 0x7f454c46@gmail.com, linux-doc@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, atwellwea@gmail.com Subject: [PATCH net 6/7] tcp: expose rmem and backlog accounting in rcvbuf_grow tracepoints Date: Wed, 11 Mar 2026 01:55:59 -0600 Message-Id: <20260311075600.948413-7-atwellwea@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260311075600.948413-1-atwellwea@gmail.com> References: <20260311075600.948413-1-atwellwea@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The receive-window work now depends on keeping sender-visible rwnd and hard receive-memory accounting aligned. Expose the current rmem charge and backlog reservation in the TCP and MPTCP rcvbuf_grow tracepoints so that later drift between advertised window and local backing is visible during review and debugging. Signed-off-by: Wesley Atwell --- include/trace/events/mptcp.h | 11 +++++++---- include/trace/events/tcp.h | 12 +++++++----- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/include/trace/events/mptcp.h b/include/trace/events/mptcp.h index 269d949b2025..167970e8e0a5 100644 --- a/include/trace/events/mptcp.h +++ b/include/trace/events/mptcp.h @@ -199,6 +199,8 @@ TRACE_EVENT(mptcp_rcvbuf_grow, __field(__u32, inq) __field(__u32, space) __field(__u32, ooo_space) + __field(__u32, rmem_alloc) + __field(__u32, backlog_len) __field(__u32, rcvbuf) __field(__u32, rcv_wnd) __field(__u8, scaling_ratio) @@ -228,6 +230,8 @@ TRACE_EVENT(mptcp_rcvbuf_grow, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq - msk->ack_seq; =20 + __entry->rmem_alloc =3D tcp_rmem_used(sk); + __entry->backlog_len =3D READ_ONCE(msk->backlog_len); __entry->rcvbuf =3D sk->sk_rcvbuf; __entry->rcv_wnd =3D atomic64_read(&msk->rcv_wnd_sent) - msk->ack_seq; @@ -248,12 +252,11 @@ TRACE_EVENT(mptcp_rcvbuf_grow, __entry->skaddr =3D sk; ), =20 - TP_printk("time=3D%u rtt_us=3D%u copied=3D%u inq=3D%u space=3D%u ooo=3D%u= scaling_ratio=3D%u " - "rcvbuf=3D%u rcv_wnd=3D%u family=3D%d sport=3D%hu dport=3D%hu saddr=3D= %pI4 " - "daddr=3D%pI4 saddrv6=3D%pI6c daddrv6=3D%pI6c skaddr=3D%p", + TP_printk("time=3D%u rtt_us=3D%u copied=3D%u inq=3D%u space=3D%u ooo=3D%u= scaling_ratio=3D%u rmem_alloc=3D%u backlog_len=3D%u rcvbuf=3D%u rcv_wnd=3D= %u family=3D%d sport=3D%hu dport=3D%hu saddr=3D%pI4 daddr=3D%pI4 saddrv6=3D= %pI6c daddrv6=3D%pI6c skaddr=3D%p", __entry->time, __entry->rtt_us, __entry->copied, __entry->inq, __entry->space, __entry->ooo_space, - __entry->scaling_ratio, __entry->rcvbuf, __entry->rcv_wnd, + __entry->scaling_ratio, __entry->rmem_alloc, + __entry->backlog_len, __entry->rcvbuf, __entry->rcv_wnd, __entry->family, __entry->sport, __entry->dport, __entry->saddr, __entry->daddr, __entry->saddr_v6, __entry->daddr_v6, __entry->skaddr) diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h index f155f95cdb6e..92d0bd6be0ba 100644 --- a/include/trace/events/tcp.h +++ b/include/trace/events/tcp.h @@ -217,6 +217,8 @@ TRACE_EVENT(tcp_rcvbuf_grow, __field(__u32, inq) __field(__u32, space) __field(__u32, ooo_space) + __field(__u32, rmem_alloc) + __field(__u32, backlog_len) __field(__u32, rcvbuf) __field(__u32, rcv_ssthresh) __field(__u32, window_clamp) @@ -247,6 +249,8 @@ TRACE_EVENT(tcp_rcvbuf_grow, TCP_SKB_CB(tp->ooo_last_skb)->end_seq - tp->rcv_nxt; =20 + __entry->rmem_alloc =3D tcp_rmem_used(sk); + __entry->backlog_len =3D READ_ONCE(sk->sk_backlog.len); __entry->rcvbuf =3D sk->sk_rcvbuf; __entry->rcv_ssthresh =3D tp->rcv_ssthresh; __entry->window_clamp =3D tp->window_clamp; @@ -269,13 +273,11 @@ TRACE_EVENT(tcp_rcvbuf_grow, __entry->sock_cookie =3D sock_gen_cookie(sk); ), =20 - TP_printk("time=3D%u rtt_us=3D%u copied=3D%u inq=3D%u space=3D%u ooo=3D%u= scaling_ratio=3D%u rcvbuf=3D%u " - "rcv_ssthresh=3D%u window_clamp=3D%u rcv_wnd=3D%u " - "family=3D%s sport=3D%hu dport=3D%hu saddr=3D%pI4 daddr=3D%pI4 " - "saddrv6=3D%pI6c daddrv6=3D%pI6c skaddr=3D%p sock_cookie=3D%llx", + TP_printk("time=3D%u rtt_us=3D%u copied=3D%u inq=3D%u space=3D%u ooo=3D%u= scaling_ratio=3D%u rmem_alloc=3D%u backlog_len=3D%u rcvbuf=3D%u rcv_ssthre= sh=3D%u window_clamp=3D%u rcv_wnd=3D%u family=3D%s sport=3D%hu dport=3D%hu = saddr=3D%pI4 daddr=3D%pI4 saddrv6=3D%pI6c daddrv6=3D%pI6c skaddr=3D%p sock_= cookie=3D%llx", __entry->time, __entry->rtt_us, __entry->copied, __entry->inq, __entry->space, __entry->ooo_space, - __entry->scaling_ratio, __entry->rcvbuf, + __entry->scaling_ratio, __entry->rmem_alloc, + __entry->backlog_len, __entry->rcvbuf, __entry->rcv_ssthresh, __entry->window_clamp, __entry->rcv_wnd, show_family_name(__entry->family), --=20 2.34.1