Hello,
While playing around with hackbench I discovered that I would sometimes
get an enormous time reported, even if the run time would be less than a
second or so. The problem was that the struct timeval start was not
initialized until after all children have been created. But if the
program receives a signal before this is done, the start time is left
uninitialized.
I propose that in such situations an error message be displayed, like
the following patch does.
Please let me know if this is acceptable.
Regards,
/Ciprian
---
diff -rupN rt-tests/src/hackbench/hackbench.c
rt-tests2/src/hackbench/hackbench.c
--- rt-tests/src/hackbench/hackbench.c 2013-12-12 16:27:06.273731063 +0200
+++ rt-tests2/src/hackbench/hackbench.c 2013-12-12 16:24:01.945738814 +0200
@@ -442,6 +442,7 @@ int main(int argc, char *argv[])
struct timeval start, stop, diff;
int readyfds[2], wakefds[2];
char dummy;
+ int timer_started = 0;
struct sched_param sp;
process_options (argc, argv);
@@ -490,6 +491,7 @@ int main(int argc, char *argv[])
}
gettimeofday(&start, NULL);
+ timer_started = 1;
/* Kick them off */
if (write(wakefds[1], &dummy, 1) != 1) {
@@ -509,8 +511,12 @@ int main(int argc, char *argv[])
gettimeofday(&stop, NULL);
/* Print time... */
- timersub(&stop, &start, &diff);
- printf("Time: %lu.%03lu\n", diff.tv_sec, diff.tv_usec/1000);
+ if (timer_started) {
+ timersub(&stop, &start, &diff);
+ printf("Time: %lu.%03lu\n", diff.tv_sec, diff.tv_usec/1000);
+ } else {
+ fprintf(stderr, "No measurements available\n");
+ }
free(child_tab);
exit(0);
}
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