mptcp: add tracepoint in mptcp_subflow_get_send

This patch added a tracepoint in the packet scheduler function
mptcp_subflow_get_send().

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/MAINTAINERS b/MAINTAINERS
index 795b9941c151ef4764e3211e8d14828ffac31e67..0f82854cc430ee6012518c3c3abc80b9f7e68f18 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12546,6 +12546,7 @@ W:      https://github.com/multipath-tcp/mptcp_net-next/wiki
 B:     https://github.com/multipath-tcp/mptcp_net-next/issues
 F:     Documentation/networking/mptcp-sysctl.rst
 F:     include/net/mptcp.h
+F:     include/trace/events/mptcp.h
 F:     include/uapi/linux/mptcp.h
 F:     net/mptcp/
 F:     tools/testing/selftests/net/mptcp/

diff --git a/include/trace/events/mptcp.h b/include/trace/events/mptcp.h
new file mode 100644 (file)
index 0000000..b1617a0
--- /dev/null
+++ b/include/trace/events/mptcp.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mptcp
+
+#if !defined(_TRACE_MPTCP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_MPTCP_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(mptcp_subflow_get_send,
+
+       TP_PROTO(struct mptcp_subflow_context *subflow),
+
+       TP_ARGS(subflow),
+
+       TP_STRUCT__entry(
+               __field(bool, active)
+               __field(bool, free)
+               __field(u32, snd_wnd)
+               __field(u32, pace)
+               __field(u8, backup)
+               __field(u64, ratio)
+       ),
+
+       TP_fast_assign(
+               struct sock *ssk;
+
+               __entry->active = mptcp_subflow_active(subflow);
+               __entry->backup = subflow->backup;
+
+               if (subflow->tcp_sock && sk_fullsock(subflow->tcp_sock))
+                       __entry->free = sk_stream_memory_free(subflow->tcp_sock);
+               else
+                       __entry->free = 0;
+
+               ssk = mptcp_subflow_tcp_sock(subflow);
+               if (ssk && sk_fullsock(ssk)) {
+                       __entry->snd_wnd = tcp_sk(ssk)->snd_wnd;
+                       __entry->pace = ssk->sk_pacing_rate;
+               } else {
+                       __entry->snd_wnd = 0;
+                       __entry->pace = 0;
+               }
+
+               if (ssk && sk_fullsock(ssk) && __entry->pace)
+                       __entry->ratio = div_u64((u64)ssk->sk_wmem_queued << 32, __entry->pace);
+               else
+                       __entry->ratio = 0;
+       ),
+
+       TP_printk("active=%d free=%d snd_wnd=%u pace=%u backup=%u ratio=%llu",
+                 __entry->active, __entry->free,
+                 __entry->snd_wnd, __entry->pace,
+                 __entry->backup, __entry->ratio)
+);
+
+#endif /* _TRACE_MPTCP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 5a05c6ca943c58e7bfcb392f977e9cb9f9e7c8ac..e26ea143754daa3393c24ec75861533d85299bba 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -25,6 +25,9 @@
 #include "protocol.h"
 #include "mib.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/mptcp.h>
+
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 struct mptcp6_sock {
        struct mptcp_sock msk;
@@ -1410,6 +1413,7 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
                send_info[i].ratio = -1;
        }
        mptcp_for_each_subflow(msk, subflow) {
+               trace_mptcp_subflow_get_send(subflow);
                ssk =  mptcp_subflow_tcp_sock(subflow);
                if (!mptcp_subflow_active(subflow))
                        continue;
@@ -1430,10 +1434,6 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
                }
        }
 
-       pr_debug("msk=%p nr_active=%d ssk=%p:%lld backup=%p:%lld",
-                msk, nr_active, send_info[0].ssk, send_info[0].ratio,
-                send_info[1].ssk, send_info[1].ratio);
-
        /* pick the best backup if no other subflow is active */
        if (!nr_active)
                send_info[0].ssk = send_info[1].ssk;