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Commit bc849872 authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
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[DCCP]: Wait for CCID 



This performs a minor optimisation: when ccid_hc_tx_send_packet
returns a value greater zero, then the same call previously was done
again at the begin of the while loop in dccp_wait_for_ccid.

This patch exploits the available information and schedule-timeouts
directly instead.

Documentation also added.

Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent af289e80

net/dccp/output.c

+19 −15
Original line number Diff line number Diff line
@@ -178,33 +178,37 @@ void dccp_write_space(struct sock *sk) 
/**

 * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet

 * @sk:    socket to wait for

 * @skb:   current skb to pass on for waiting

 * @delay: sleep timeout in milliseconds (> 0)

 * This function is called by default when the socket is closed, and

 * when a non-zero linger time is set on the socket. For consistency

 */

static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb)

static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay)

{

	struct dccp_sock *dp = dccp_sk(sk);

	DEFINE_WAIT(wait);

	unsigned long delay;

	unsigned long jiffdelay;

	int rc;



	while (1) {

	do {

		dccp_pr_debug("delayed send by %d msec\n", delay);

		jiffdelay = msecs_to_jiffies(delay);



		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);



		sk->sk_write_pending++;

		release_sock(sk);

		schedule_timeout(jiffdelay);

		lock_sock(sk);

		sk->sk_write_pending--;



		if (sk->sk_err)

			goto do_error;

		if (signal_pending(current))

			goto do_interrupted;



		rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);

		if (rc <= 0)

			break;

		dccp_pr_debug("delayed send by %d msec\n", rc);

		delay = msecs_to_jiffies(rc);

		sk->sk_write_pending++;

		release_sock(sk);

		schedule_timeout(delay);

		lock_sock(sk);

		sk->sk_write_pending--;

	}

	} while ((delay = rc) > 0);

out:

	finish_wait(sk->sk_sleep, &wait);

	return rc;
@@ -231,7 +235,7 @@ void dccp_write_xmit(struct sock *sk, int block) 
						msecs_to_jiffies(err)+jiffies);

				break;

			} else

				err = dccp_wait_for_ccid(sk, skb);

				err = dccp_wait_for_ccid(sk, skb, err);

			if (err && err != -EINTR)

				DCCP_BUG("err=%d after dccp_wait_for_ccid", err);

		}