From: Jim Somerville <Jim.Somerville@xxxxxxxxxxxxx>
Huge latencies are observed (close to 1 second) when certain
options are used in cyclictest.
The problem was 1st introduced at commit da4956cbcaf7945554f
("use interval on first loop instead of 1 second"). It removed
the 1 second first timing loop out of the main path in cyclictest
but left it in two other paths, namely the ones triggered by
these two options:
-r --relative use relative timer instead of absolute
-s --system use sys_nanosleep and sys_setitimer
which in turn causes the huge latencies of close to 1 second to
be reported by cyclictest with certain uses of those two options.
Here we extend the original commit to remove the 1 second
hardcoded timer values from the RELTIME and ITIMER options, by
simply using the actual interval provided instead.
Signed-off-by: Jim Somerville <Jim.Somerville@xxxxxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: John Kacur <jkacur@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index abf3e8b..8c93ccb 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -775,17 +775,15 @@ void *timerthread(void *param)
if (par->timermode == TIMER_ABSTIME)
tspec.it_value = next;
else {
- tspec.it_value.tv_nsec = 0;
- tspec.it_value.tv_sec = 1;
+ tspec.it_value = interval;
}
timer_settime(timer, par->timermode, &tspec, NULL);
}
if (par->mode == MODE_SYS_ITIMER) {
- itimer.it_value.tv_sec = 1;
- itimer.it_value.tv_usec = 0;
itimer.it_interval.tv_sec = interval.tv_sec;
itimer.it_interval.tv_usec = interval.tv_nsec / 1000;
+ itimer.it_value = itimer.it_interval;
setitimer (ITIMER_REAL, &itimer, NULL);
}
--
1.8.1.2
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