[tip:perf/core] perf test: Add test for the evlist mmap routines

tip-bot for Arnaldo Carvalho de Melo
2011-01-26T07:20:29Z

Commit-ID: de5fa3a8a05cd60f59622e88cfeb90416760d78e
Gitweb: http://git.kernel.org/tip/de5fa3a8a05cd60f59622e88cfeb90416760d78e
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Sat, 15 Jan 2011 10:42:46 -0200
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Sat, 22 Jan 2011 19:56:31 -0200

perf test: Add test for the evlist mmap routines

This test will generate random numbers of calls to some getpid syscalls,
then establish an mmap for a group of events that are created to monitor
these syscalls.

It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
sample.id field to map back to its respective perf_evsel instance.

Then it checks if the number of syscalls reported as perf events by the
kernel corresponds to the number of syscalls made.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-test.c | 171 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 169 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 5a50e47..4fd3453 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -7,7 +7,9 @@

#include "util/cache.h"
#include "util/debug.h"
+#include "util/evlist.h"
#include "util/parse-options.h"
+#include "util/parse-events.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/thread.h"
@@ -238,14 +240,14 @@ out:
#include "util/evsel.h"
#include <sys/types.h>

-static int trace_event__id(const char *event_name)
+static int trace_event__id(const char *evname)
{
char *filename;
int err = -1, fd;

if (asprintf(&filename,
"/sys/kernel/debug/tracing/events/syscalls/%s/id",
- event_name) < 0)
+ evname) < 0)
return -1;

fd = open(filename, O_RDONLY);
@@ -439,6 +441,167 @@ out_thread_map_delete:
return err;
}

+/*
+ * This test will generate random numbers of calls to some getpid syscalls,
+ * then establish an mmap for a group of events that are created to monitor
+ * the syscalls.
+ *
+ * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
+ * sample.id field to map back to its respective perf_evsel instance.
+ *
+ * Then it checks if the number of syscalls reported as perf events by
+ * the kernel corresponds to the number of syscalls made.
+ */
+static int test__basic_mmap(void)
+{
+ int err = -1;
+ event_t *event;
+ struct thread_map *threads;
+ struct perf_session session;
+ struct cpu_map *cpus;
+ struct perf_evlist *evlist;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_TRACEPOINT,
+ .read_format = PERF_FORMAT_ID,
+ .sample_type = PERF_SAMPLE_ID,
+ .watermark = 0,
+ };
+ cpu_set_t cpu_set;
+ const char *syscall_names[] = { "getsid", "getppid", "getpgrp",
+ "getpgid", };
+ pid_t (*syscalls[])(void) = { (void *)getsid, getppid, getpgrp,
+ (void*)getpgid };
+#define nsyscalls ARRAY_SIZE(syscall_names)
+ int ids[nsyscalls];
+ unsigned int nr_events[nsyscalls],
+ expected_nr_events[nsyscalls], i, j;
+ struct perf_evsel *evsels[nsyscalls], *evsel;
+
+ for (i = 0; i < nsyscalls; ++i) {
+ char name[64];
+
+ snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
+ ids[i] = trace_event__id(name);
+ if (ids[i] < 0) {
+ pr_debug("Is debugfs mounted on /sys/kernel/debug?\n");
+ return -1;
+ }
+ nr_events[i] = 0;
+ expected_nr_events[i] = random() % 257;
+ }
+
+ threads = thread_map__new(-1, getpid());
+ if (threads == NULL) {
+ pr_debug("thread_map__new\n");
+ return -1;
+ }
+
+ cpus = cpu_map__new(NULL);
+ if (threads == NULL) {
+ pr_debug("thread_map__new\n");
+ goto out_free_threads;
+ }
+
+ CPU_ZERO(&cpu_set);
+ CPU_SET(cpus->map[0], &cpu_set);
+ sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
+ if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
+ pr_debug("sched_setaffinity() failed on CPU %d: %s ",
+ cpus->map[0], strerror(errno));
+ goto out_free_cpus;
+ }
+
+ evlist = perf_evlist__new();
+ if (threads == NULL) {
+ pr_debug("perf_evlist__new\n");
+ goto out_free_cpus;
+ }
+
+ /* anonymous union fields, can't be initialized above */
+ attr.wakeup_events = 1;
+ attr.sample_period = 1;
+
+ /*
+ * FIXME: use evsel->attr.sample_type in event__parse_sample.
+ * This will nicely remove the requirement that we have
+ * all the events with the same sample_type.
+ */
+ session.sample_type = attr.sample_type;
+
+ for (i = 0; i < nsyscalls; ++i) {
+ attr.config = ids[i];
+ evsels[i] = perf_evsel__new(&attr, i);
+ if (evsels[i] == NULL) {
+ pr_debug("perf_evsel__new\n");
+ goto out_free_evlist;
+ }
+
+ perf_evlist__add(evlist, evsels[i]);
+
+ if (perf_evsel__open(evsels[i], cpus, threads, false, false) < 0) {
+ pr_debug("failed to open counter: %s, "
+ "tweak /proc/sys/kernel/perf_event_paranoid?\n",
+ strerror(errno));
+ goto out_close_fd;
+ }
+ }
+
+ if (perf_evlist__mmap(evlist, cpus, threads, 128, true) < 0) {
+ pr_debug("failed to mmap events: %d (%s)\n", errno,
+ strerror(errno));
+ goto out_close_fd;
+ }
+
+ for (i = 0; i < nsyscalls; ++i)
+ for (j = 0; j < expected_nr_events[i]; ++j) {
+ int foo = syscalls[i]();
+ ++foo;
+ }
+
+ while ((event = perf_evlist__read_on_cpu(evlist, 0)) != NULL) {
+ struct sample_data sample;
+
+ if (event->header.type != PERF_RECORD_SAMPLE) {
+ pr_debug("unexpected %s event\n",
+ event__get_event_name(event->header.type));
+ goto out_munmap;
+ }
+
+ event__parse_sample(event, &session, &sample);
+ evsel = perf_evlist__id2evsel(evlist, sample.id);
+ if (evsel == NULL) {
+ pr_debug("event with id %" PRIu64
+ " doesn't map to an evsel\n", sample.id);
+ goto out_munmap;
+ }
+ nr_events[evsel->idx]++;
+ }
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
+ pr_debug("expected %d %s events, got %d\n",
+ expected_nr_events[evsel->idx],
+ event_name(evsel), nr_events[evsel->idx]);
+ goto out_munmap;
+ }
+ }
+
+ err = 0;
+out_munmap:
+ perf_evlist__munmap(evlist, 1);
+out_close_fd:
+ for (i = 0; i < nsyscalls; ++i)
+ perf_evsel__close_fd(evsels[i], 1, threads->nr);
+out_free_evlist:
+ perf_evlist__delete(evlist);
+out_free_cpus:
+ cpu_map__delete(cpus);
+out_free_threads:
+ thread_map__delete(threads);
+ return err;
+#undef nsyscalls
+}
+
static struct test {
const char *desc;
int (*func)(void);
@@ -456,6 +619,10 @@ static struct test {
.func = test__open_syscall_event_on_all_cpus,
},
{
+ .desc = "read samples using the mmap interface",
+ .func = test__basic_mmap,
+ },
+ {
.func = NULL,
},
};