Re: [PATCH 07/10] libperf: Add tests_mmap_cpus test

Arnaldo Carvalho de Melo
2019-10-18T18:16:48Z

Em Fri, Oct 18, 2019 at 03:14:29PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Oct 17, 2019 at 12:59:15PM +0200, Jiri Olsa escreveu:
> > Adding mmaping tests that generates prctl call on
> > every cpu validates it gets all the related events
> > in ring buffer.
>
> So _here_ we need _GNU_SOURCE, for this specific test:

Added, to this test:

[acme@quaco perf]$ git diff
diff --git a/tools/perf/lib/tests/test-evlist.c b/tools/perf/lib/tests/test-evlist.c
index d8c52ebfa53a..741bc1bb4524 100644
--- a/tools/perf/lib/tests/test-evlist.c
+++ b/tools/perf/lib/tests/test-evlist.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
-#include <stdio.h>
+#define _GNU_SOURCE // needed for sched.h to get sched_[gs]etaffinity and CPU_(ZERO,SET)
#include <sched.h>
+#include <stdio.h>
#include <stdarg.h>
#include <unistd.h>
#include <stdlib.h>
[acme@quaco perf]$

We can go the big hammer way if this is more generally needed, but first
lets try to use it only when needed, ok?

- Arnaldo

> LINK test-evlist-a
> test-evlist.c: In function ‘test_mmap_cpus’:
> test-evlist.c:352:8: warning: implicit declaration of function ‘sched_getaffinity’ [-Wimplicit-function-declaration]
> 352 | err = sched_getaffinity(0, sizeof(saved_mask), &saved_mask);
> | ^~~~~~~~~~~~~~~~~
> test-evlist.c:358:3: warning: implicit declaration of function ‘CPU_ZERO’ [-Wimplicit-function-declaration]
> 358 | CPU_ZERO(&mask);
> | ^~~~~~~~
> test-evlist.c:359:3: warning: implicit declaration of function ‘CPU_SET’ [-Wimplicit-function-declaration]
> 359 | CPU_SET(cpu, &mask);
> | ^~~~~~~
> test-evlist.c:361:9: warning: implicit declaration of function ‘sched_setaffinity’ [-Wimplicit-function-declaration]
> 361 | err = sched_setaffinity(0, sizeof(mask), &mask);
> | ^~~~~~~~~~~~~~~~~
> /usr/bin/ld: /tmp/ccOhNrLC.o: in function `test_mmap_cpus':
> /home/acme/git/perf/tools/perf/lib/tests/test-evlist.c:358: undefined reference to `CPU_ZERO'
> /usr/bin/ld: /home/acme/git/perf/tools/perf/lib/tests/test-evlist.c:359: undefined reference to `CPU_SET'
> collect2: error: ld returned 1 exit status
> make[1]: *** [Makefile:22: test-evlist-a] Error 1
> make: *** [Makefile:143: tests] Error 2
> make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
> [root@quaco perf]#
>
> > Link: http://lkml.kernel.org/n/tip-9qdckblmgjm42ofd7haflso0@git.kernel.org
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > tools/perf/lib/tests/test-evlist.c | 97 ++++++++++++++++++++++++++++++
> > 1 file changed, 97 insertions(+)
> >
> > diff --git a/tools/perf/lib/tests/test-evlist.c b/tools/perf/lib/tests/test-evlist.c
> > index 90a1869ba4b1..d8c52ebfa53a 100644
> > --- a/tools/perf/lib/tests/test-evlist.c
> > +++ b/tools/perf/lib/tests/test-evlist.c
> > @@ -1,5 +1,6 @@
> > // SPDX-License-Identifier: GPL-2.0
> > #include <stdio.h>
> > +#include <sched.h>
> > #include <stdarg.h>
> > #include <unistd.h>
> > #include <stdlib.h>
> > @@ -299,6 +300,101 @@ static int test_mmap_thread(void)
> > return 0;
> > }
> >
> > +static int test_mmap_cpus(void)
> > +{
> > + struct perf_evlist *evlist;
> > + struct perf_evsel *evsel;
> > + struct perf_mmap *map;
> > + struct perf_cpu_map *cpus;
> > + struct perf_event_attr attr = {
> > + .type = PERF_TYPE_TRACEPOINT,
> > + .sample_period = 1,
> > + .wakeup_watermark = 1,
> > + .disabled = 1,
> > + };
> > + cpu_set_t saved_mask;
> > + char path[PATH_MAX];
> > + int id, err, cpu, tmp;
> > + union perf_event *event;
> > + int count = 0;
> > +
> > + snprintf(path, PATH_MAX, "%s/kernel/debug/tracing/events/syscalls/sys_enter_prctl/id",
> > + sysfs__mountpoint());
> > +
> > + if (filename__read_int(path, &id)) {
> > + fprintf(stderr, "error: failed to get tracepoint id: %s\n", path);
> > + return -1;
> > + }
> > +
> > + attr.config = id;
> > +
> > + cpus = perf_cpu_map__new(NULL);
> > + __T("failed to create cpus", cpus);
> > +
> > + evlist = perf_evlist__new();
> > + __T("failed to create evlist", evlist);
> > +
> > + evsel = perf_evsel__new(&attr);
> > + __T("failed to create evsel1", evsel);
> > +
> > + perf_evlist__add(evlist, evsel);
> > +
> > + perf_evlist__set_maps(evlist, cpus, NULL);
> > +
> > + err = perf_evlist__open(evlist);
> > + __T("failed to open evlist", err == 0);
> > +
> > + err = perf_evlist__mmap(evlist, 4);
> > + __T("failed to mmap evlist", err == 0);
> > +
> > + perf_evlist__enable(evlist);
> > +
> > + err = sched_getaffinity(0, sizeof(saved_mask), &saved_mask);
> > + __T("sched_getaffinity failed", err == 0);
> > +
> > + perf_cpu_map__for_each_cpu(cpu, tmp, cpus) {
> > + cpu_set_t mask;
> > +
> > + CPU_ZERO(&mask);
> > + CPU_SET(cpu, &mask);
> > +
> > + err = sched_setaffinity(0, sizeof(mask), &mask);
> > + __T("sched_setaffinity failed", err == 0);
> > +
> > + prctl(0, 0, 0, 0, 0);
> > + }
> > +
> > + err = sched_setaffinity(0, sizeof(saved_mask), &saved_mask);
> > + __T("sched_setaffinity failed", err == 0);
> > +
> > + perf_evlist__disable(evlist);
> > +
> > + perf_evlist__for_each_mmap(evlist, map, false) {
> > + if (perf_mmap__read_init(map) < 0)
> > + continue;
> > +
> > + while ((event = perf_mmap__read_event(map)) != NULL) {
> > + count++;
> > + perf_mmap__consume(map);
> > + }
> > +
> > + perf_mmap__read_done(map);
> > + }
> > +
> > + /* calls perf_evlist__munmap/perf_evlist__close */
> > + perf_evlist__delete(evlist);
> > +
> > + /*
> > + * The generated prctl events should match the
> > + * number of cpus or be bigger (we are system-wide).
> > + */
> > + __T("failed count", count >= perf_cpu_map__nr(cpus));
> > +
> > + perf_cpu_map__put(cpus);
> > +
> > + return 0;
> > +}
> > +
> > int main(int argc, char **argv)
> > {
> > __T_START;
> > @@ -309,6 +405,7 @@ int main(int argc, char **argv)
> > test_stat_thread();
> > test_stat_thread_enable();
> > test_mmap_thread();
> > + test_mmap_cpus();
> >
> > __T_OK;
> > return 0;
> > --
> > 2.21.0
>
> --
>
> - Arnaldo

--

- Arnaldo