On Thu, 30 Jun 2022, Song Chen wrote:
> cyclictest has tracelimit to stop running when max latency
> is higher than threshold but cyclicdeadline doesn't.
>
> Therefore, tracelimit is introduced to cyclicdeadline in
> this commit, once max latency is over, test stops and log
> prints at the bottom of the ftrace file.
>
> Signed-off-by: Song Chen <chensong_2000@xxxxxx>
> Reviewed-by: Daniel Wagner <wagi@xxxxxxxxx>
>
> ---
> v2:
> 1, disable ftrace when hitting thresold
>
> v3:
> 1, update man page
> ---
> src/sched_deadline/cyclicdeadline.8 | 6 ++++
> src/sched_deadline/cyclicdeadline.c | 49 ++++++++++++++++++++++++++---
> 2 files changed, 51 insertions(+), 4 deletions(-)
>
> diff --git a/src/sched_deadline/cyclicdeadline.8 b/src/sched_deadline/cyclicdeadline.8
> index 1a56ed0..fab301e 100644
> --- a/src/sched_deadline/cyclicdeadline.8
> +++ b/src/sched_deadline/cyclicdeadline.8
> @@ -50,6 +50,12 @@ The number of threads to run as deadline (default 1)
> .B \-q, \-\-quiet
> Print a summary only on exit. Useful for automated tests, where only
> the summary output needs to be captured.
> +.TP
> +.B \-b, \-\-breaktrace=USEC
> +Send break trace command when latency > USEC
> +.TP
> +.B \-\-tracemark
> +write a trace mark when \-b latency is exceeded.
> .br
> .SH AUTHOR
> cyclicdeadline was written by Steven Rostedt <rostedt@xxxxxxxxxxx>
> diff --git a/src/sched_deadline/cyclicdeadline.c b/src/sched_deadline/cyclicdeadline.c
> index d865fa3..a925d1c 100644
> --- a/src/sched_deadline/cyclicdeadline.c
> +++ b/src/sched_deadline/cyclicdeadline.c
> @@ -80,7 +80,11 @@ struct sched_data {
> };
>
> static int shutdown;
> -
> +static int tracelimit = 0;
> +static int trace_marker = 0;
> +static pthread_mutex_t break_thread_id_lock = PTHREAD_MUTEX_INITIALIZER;
> +static pid_t break_thread_id = 0;
> +static uint64_t break_thread_value = 0;
> static pthread_barrier_t barrier;
>
> static int cpu_count;
> @@ -667,6 +671,10 @@ static void teardown(void)
>
> destroy_cpuset(CPUSET_ALL, 0);
> destroy_cpuset(CPUSET_LOCAL, 1);
> +
> + /* close any tracer file descriptors */
> + disable_trace_mark();
> +
> }
>
> static void usage(int error)
> @@ -689,6 +697,8 @@ static void usage(int error)
> " (default 500us).\n"
> "-t NUM --threads The number of threads to run as deadline (default 1).\n"
> "-q --quiet print a summary only on exit\n"
> + "-b USEC --breaktrace=USEC send break trace command when latency > USEC\n"
> + " --tracemark write a trace mark when -b latency is exceeded\n"
> );
> exit(error);
> }
> @@ -825,6 +835,18 @@ void *run_deadline(void *data)
>
> while (!shutdown) {
> period = do_runtime(tid, sd, period);
> + if (tracelimit && (stat->max > tracelimit)) {
> + shutdown++;
> + pthread_mutex_lock(&break_thread_id_lock);
> + if (break_thread_id == 0) {
> + break_thread_id = stat->tid;
> + break_thread_value = stat->max;
> + tracemark( "hit latency threshold (%lld > %d)",
> + (unsigned long long) stat->max, tracelimit);
> + }
> + pthread_mutex_unlock(&break_thread_id_lock);
> + break;
> + }
> sched_yield();
> }
> ret = sched_getattr(0, &attr, sizeof(attr), 0);
> @@ -1063,9 +1085,10 @@ static void write_stats(FILE *f, void *data)
> fprintf(f, " }\n");
> }
>
> -enum options_valud {
> +enum options_values {
> OPT_AFFINITY=1, OPT_DURATION, OPT_HELP, OPT_INTERVAL,
> - OPT_JSON, OPT_STEP, OPT_THREADS, OPT_QUIET
> + OPT_JSON, OPT_STEP, OPT_THREADS, OPT_QUIET,
> + OPT_BREAKTRACE, OPT_TRACEMARK,
> };
>
> int main(int argc, char **argv)
> @@ -1104,9 +1127,11 @@ int main(int argc, char **argv)
> { "step", required_argument, NULL, OPT_STEP },
> { "threads", required_argument, NULL, OPT_THREADS },
> { "quiet", no_argument, NULL, OPT_QUIET },
> + { "breaktrace", required_argument, NULL, OPT_BREAKTRACE },
> + { "tracemark", no_argument, NULL, OPT_TRACEMARK },
> { NULL, 0, NULL, 0 },
> };
> - c = getopt_long(argc, argv, "a::c:D:hi:s:t:q", options, NULL);
> + c = getopt_long(argc, argv, "a::c:D:hi:s:t:b:q", options, NULL);
> if (c == -1)
> break;
> switch (c) {
> @@ -1141,6 +1166,10 @@ int main(int argc, char **argv)
> case 'D':
> duration = parse_time_string(optarg);
> break;
> + case 'b':
> + case OPT_BREAKTRACE:
> + tracelimit = atoi(optarg);
> + break;
> case OPT_QUIET:
> case 'q':
> quiet = 1;
> @@ -1149,6 +1178,9 @@ int main(int argc, char **argv)
> case 'h':
> usage(0);
> break;
> + case OPT_TRACEMARK:
> + trace_marker = 1;
> + break;
> default:
> usage(1);
> }
> @@ -1186,6 +1218,8 @@ int main(int argc, char **argv)
> warn("mlockall");
>
> setup_ftrace_marker();
> + if (tracelimit && trace_marker)
> + enable_trace_mark();
>
> thread = calloc(nr_threads, sizeof(*thread));
> sched_data = calloc(nr_threads, sizeof(*sched_data));
> @@ -1294,6 +1328,13 @@ int main(int argc, char **argv)
>
> loop(sched_data, nr_threads);
>
> + if (tracelimit) {
> + if (break_thread_id) {
> + printf("# Break thread: %d\n", break_thread_id);
> + printf("# Break value: %llu\n", (unsigned long long)break_thread_value);
> + }
> + }
> +
> for (i = 0; i < nr_threads; i++) {
>
> sd = &sched_data[i];
> --
> 2.25.1
>
>
- Fixed style problems reported by checkpatch from kernel, namely
- Don't initialize static to 0
- no space after open parenthesis
- removed multiple spaces after Reviewed-by
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
