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

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

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:

  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