core: add tracepoints for queueing skb to rcvbuf
This patch adds 2 tracepoints to get a status of a socket receive queue
and related parameter.
One tracepoint is added to sock_queue_rcv_skb. It records rcvbuf size
and its usage. The other tracepoint is added to __sk_mem_schedule and
it records limitations of memory for sockets and current usage.
By using these tracepoints we're able to know detailed reason why kernel
drop the packet.
Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sock.c b/net/core/sock.c
index 6e81978..76c4031 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -128,6 +128,8 @@
#include <linux/filter.h>
+#include <trace/events/sock.h>
+
#ifdef CONFIG_INET
#include <net/tcp.h>
#endif
@@ -292,6 +294,7 @@
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
(unsigned)sk->sk_rcvbuf) {
atomic_inc(&sk->sk_drops);
+ trace_sock_rcvqueue_full(sk, skb);
return -ENOMEM;
}
@@ -1736,6 +1739,8 @@
return 1;
}
+ trace_sock_exceed_buf_limit(sk, prot, allocated);
+
/* Alas. Undo changes. */
sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
atomic_long_sub(amt, prot->memory_allocated);