kernel_optimize_test/tools/perf/tests/sw-clock.c
Namhyung Kim bc96b361cb perf tests: Add a test case for checking sw clock event frequency
This test case checks frequency conversion of hrtimer-based software
clock events (cpu-clock, task-clock) have valid (non-1) periods.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1363574507-18808-2-git-send-email-namhyung@kernel.org
[ committer note: Moved .sample_freq to outside named init block to cope with some gcc versions ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-03-18 11:43:16 -03:00

120 lines
2.5 KiB
C

#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/mman.h>
#include "tests.h"
#include "util/evsel.h"
#include "util/evlist.h"
#include "util/cpumap.h"
#include "util/thread_map.h"
#define NR_LOOPS 1000000
/*
* This test will open software clock events (cpu-clock, task-clock)
* then check their frequency -> period conversion has no artifact of
* setting period to 1 forcefully.
*/
static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
{
int i, err = -1;
volatile int tmp = 0;
u64 total_periods = 0;
int nr_samples = 0;
union perf_event *event;
struct perf_evsel *evsel;
struct perf_evlist *evlist;
struct perf_event_attr attr = {
.type = PERF_TYPE_SOFTWARE,
.config = clock_id,
.sample_type = PERF_SAMPLE_PERIOD,
.exclude_kernel = 1,
.disabled = 1,
.freq = 1,
};
attr.sample_freq = 10000;
evlist = perf_evlist__new();
if (evlist == NULL) {
pr_debug("perf_evlist__new\n");
return -1;
}
evsel = perf_evsel__new(&attr, 0);
if (evsel == NULL) {
pr_debug("perf_evsel__new\n");
goto out_free_evlist;
}
perf_evlist__add(evlist, evsel);
evlist->cpus = cpu_map__dummy_new();
evlist->threads = thread_map__new_by_tid(getpid());
if (!evlist->cpus || !evlist->threads) {
err = -ENOMEM;
pr_debug("Not enough memory to create thread/cpu maps\n");
goto out_delete_maps;
}
perf_evlist__open(evlist);
err = perf_evlist__mmap(evlist, 128, true);
if (err < 0) {
pr_debug("failed to mmap event: %d (%s)\n", errno,
strerror(errno));
goto out_close_evlist;
}
perf_evlist__enable(evlist);
/* collect samples */
for (i = 0; i < NR_LOOPS; i++)
tmp++;
perf_evlist__disable(evlist);
while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
struct perf_sample sample;
if (event->header.type != PERF_RECORD_SAMPLE)
continue;
err = perf_evlist__parse_sample(evlist, event, &sample);
if (err < 0) {
pr_debug("Error during parse sample\n");
goto out_unmap_evlist;
}
total_periods += sample.period;
nr_samples++;
}
if ((u64) nr_samples == total_periods) {
pr_debug("All (%d) samples have period value of 1!\n",
nr_samples);
err = -1;
}
out_unmap_evlist:
perf_evlist__munmap(evlist);
out_close_evlist:
perf_evlist__close(evlist);
out_delete_maps:
perf_evlist__delete_maps(evlist);
out_free_evlist:
perf_evlist__delete(evlist);
return err;
}
int test__sw_clock_freq(void)
{
int ret;
ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
if (!ret)
ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
return ret;
}