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cyclictest: Fix tracemark output when the latency threshold is hit on ARM 

on ARM I'm seeing output like:

	cyclicte-623     0....... 19619418us+: tracing_mark_write: hit latency threshold (2000 > 2097)

That's because of a format mismatch in

	tracemark("hit latency threshold (%d > %d)", diff, tracelimit);

diff is a u64 and tracelimit an int. So on ARM the string is passed in r0,
tracelimit in r1 and diff in r2+r3. vsnprintf used in tracemark only
expects two ints passed and so only uses r1 and r2 yielding the permutation
in the output.

This patch also adds a gcc attribute to tracemark that helps catching
similar bugs. In this case just adding the attribute but not touching
the call site, would result in:

	src/cyclictest/cyclictest.c: In function ‘timerthread’:
	src/cyclictest/cyclictest.c:899:4: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘uint64_t’ [-Wformat]

---
Hello

after some chatting with Clark and John I dropped the c99 stuff and added the
attribute annotation.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clark Williams <clark.williams@gmail.com>
This commit is contained in:
Uwe Kleine-König 2014-01-31 14:07:20 -06:00 committed by Clark Williams
parent 3917fdbe56
commit 87f1158245
1 changed files with 3 additions and 1 deletions
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4
src/cyclictest/cyclictest.c
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@ -400,6 +400,7 @@ static int trace_file_exists(char *name)
#define TRACEBUFSIZ 1024
static __thread char tracebuf[TRACEBUFSIZ];
static void tracemark(char *fmt, ...) __attribute__((format(printf, 1, 2)));
static void tracemark(char *fmt, ...)
{
va_list ap;
@ -895,7 +896,8 @@ void *timerthread(void *param)
if (!stopped && tracelimit && (diff > tracelimit)) {
stopped++;
tracemark("hit latency threshold (%d > %d)", diff, tracelimit);
tracemark("hit latency threshold (%llu > %d)",
(unsigned long long) diff, tracelimit);
tracing(0);
shutdown++;
pthread_mutex_lock(&break_thread_id_lock);