Commit 1033990a authored Apr 15, 2019 by Xin Long Committed by David S. Miller Apr 15, 2019

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 <mcroce@redhat.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 93144b0e

net/sctp/socket.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -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

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