sctp: implement memory accounting on tx path

Now when sending packets, sk_mem_charge() and sk_mem_uncharge() have been used to set sk_forward_alloc. We just need to call sk_wmem_schedule() to check if the allocated should be raised, and call sk_mem_reclaim() to check if the allocated should be reduced when it's under memory pressure. If sk_wmem_schedule() returns false, which means no memory is allowed to allocate, it will block and wait for memory to become available. Note different from tcp, sctp wait_for_buf happens before allocating any skb, so memory accounting check is done with the whole msg_len before it too. Reported-by: Matteo Croce <[email protected]> Tested-by: Matteo Croce <[email protected]> Acked-by: Neil Horman <[email protected]> Acked-by: Marcelo Ricardo Leitner <[email protected]> Signed-off-by: Xin Long <[email protected]> Signed-off-by: David S. Miller <[email protected]>
modi0012 · Apr 15, 2019 · 1033990 · 1033990
1 parent 93144b0
commit 1033990
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
@@ -1913,7 +1913,10 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
 	if (sctp_wspace(asoc) < (int)msg_len)
 		sctp_prsctp_prune(asoc, sinfo, msg_len - sctp_wspace(asoc));
 
-	if (sctp_wspace(asoc) <= 0) {
+	if (sk_under_memory_pressure(sk))
+		sk_mem_reclaim(sk);
+
+	if (sctp_wspace(asoc) <= 0 || !sk_wmem_schedule(sk, msg_len)) {
 		timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 		err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
 		if (err)
@@ -8930,7 +8933,10 @@ static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
 			goto do_error;
 		if (signal_pending(current))
 			goto do_interrupted;
-		if ((int)msg_len <= sctp_wspace(asoc))
+		if (sk_under_memory_pressure(sk))
+			sk_mem_reclaim(sk);
+		if ((int)msg_len <= sctp_wspace(asoc) &&
+		    sk_wmem_schedule(sk, msg_len))
 			break;
 
 		/* Let another process have a go.  Since we are going