wrs-socket: decrease the timeout when waiting for a timestamp

Even under load, with queues full, the wrs delays frames less than one ms. Thus, if we didn't get a timestamp in 1ms, we won't ever get it. Add some software delay and clearly we don't need 100ms as in current code. Please note that all state machines are not running during this wait, as we are single-process single-thread. So now we wait for 6ms at most (3 times 2ms at most, but the first time we may get an older timestamp, then discarded). Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

wrs-socket: decrease the timeout when waiting for a timestamp
Even under load, with queues full, the wrs delays frames less than one ms. Thus, if we didn't get a timestamp in 1ms, we won't ever get it. Add some software delay and clearly we don't need 100ms as in current code. Please note that all state machines are not running during this wait, as we are single-process single-thread. So now we wait for 6ms at most (3 times 2ms at most, but the first time we may get an older timestamp, then discarded). Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
2f989cb5 · Alessandro Rubini · 9250cea8 · 2f989cb5
Commit 2f989cb5 authored Aug 21, 2015 by Alessandro Rubini
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wrs-socket.c time-wrs/wrs-socket.c +2 -2

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--- a/time-wrs/wrs-socket.c
+++ b/time-wrs/wrs-socket.c
@@ -370,10 +370,10 @@ static void poll_tx_timestamp(struct pp_instance *ppi, void *pkt, int len,
 	pfd.fd = fd;
 	pfd.events = POLLERR;

-	#define N_RETRY 5
+	#define N_RETRY 3
 	for (retry = 0; retry < N_RETRY; retry++) {
 		errno = 0;
-		res = poll(&pfd, 1, 20 /* ms */);
+		res = poll(&pfd, 1, 2 /* ms */);
 		if (res < 0 && errno != EAGAIN) {
 			pp_diag(ppi, time, 1, "%s: poll() = %i (%s)\n",
 				__func__, res, strerror(errno));