[tip:perf/core] perf tests: Add a test for tracking with sched_switch

From: tip-bot for Adrian Hunter
Date: Sun Aug 24 2014 - 11:02:42 EST


Commit-ID: d44bc558297222d9a621fff2eca3f880e91c49f7
Gitweb: http://git.kernel.org/tip/d44bc558297222d9a621fff2eca3f880e91c49f7
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Fri, 15 Aug 2014 22:08:36 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 22 Aug 2014 13:10:35 -0300

perf tests: Add a test for tracking with sched_switch

Add a test that checks that sched_switch events and tracking events can
be recorded for a workload using the evsel->system_wide and
evsel->tracking flags (respectively) with other events sometimes enabled
or disabled.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1408129739-17368-2-git-send-email-adrian.hunter@xxxxxxxxx
[ Fix build on fedora14 by using a designated initializer for the sched_switch variable ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile.perf | 1 +
tools/perf/tests/builtin-test.c | 4 +
tools/perf/tests/switch-tracking.c | 572 +++++++++++++++++++++++++++++++++++++
tools/perf/tests/tests.h | 1 +
4 files changed, 578 insertions(+)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 1ea31e2..95e832b 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -425,6 +425,7 @@ endif
endif
LIB_OBJS += $(OUTPUT)tests/mmap-thread-lookup.o
LIB_OBJS += $(OUTPUT)tests/thread-mg-share.o
+LIB_OBJS += $(OUTPUT)tests/switch-tracking.o

BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 9948136..6a4145e 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -154,6 +154,10 @@ static struct test {
.func = test__hists_cumulate,
},
{
+ .desc = "Test tracking with sched_switch",
+ .func = test__switch_tracking,
+ },
+ {
.func = NULL,
},
};
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
new file mode 100644
index 0000000..cc68648
--- /dev/null
+++ b/tools/perf/tests/switch-tracking.c
@@ -0,0 +1,572 @@
+#include <sys/time.h>
+#include <sys/prctl.h>
+#include <time.h>
+#include <stdlib.h>
+
+#include "parse-events.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "thread_map.h"
+#include "cpumap.h"
+#include "tests.h"
+
+static int spin_sleep(void)
+{
+ struct timeval start, now, diff, maxtime;
+ struct timespec ts;
+ int err, i;
+
+ maxtime.tv_sec = 0;
+ maxtime.tv_usec = 50000;
+
+ err = gettimeofday(&start, NULL);
+ if (err)
+ return err;
+
+ /* Spin for 50ms */
+ while (1) {
+ for (i = 0; i < 1000; i++)
+ barrier();
+
+ err = gettimeofday(&now, NULL);
+ if (err)
+ return err;
+
+ timersub(&now, &start, &diff);
+ if (timercmp(&diff, &maxtime, > /* For checkpatch */))
+ break;
+ }
+
+ ts.tv_nsec = 50 * 1000 * 1000;
+ ts.tv_sec = 0;
+
+ /* Sleep for 50ms */
+ err = nanosleep(&ts, NULL);
+ if (err == EINTR)
+ err = 0;
+
+ return err;
+}
+
+struct switch_tracking {
+ struct perf_evsel *switch_evsel;
+ struct perf_evsel *cycles_evsel;
+ pid_t *tids;
+ int nr_tids;
+ int comm_seen[4];
+ int cycles_before_comm_1;
+ int cycles_between_comm_2_and_comm_3;
+ int cycles_after_comm_4;
+};
+
+static int check_comm(struct switch_tracking *switch_tracking,
+ union perf_event *event, const char *comm, int nr)
+{
+ if (event->header.type == PERF_RECORD_COMM &&
+ (pid_t)event->comm.pid == getpid() &&
+ (pid_t)event->comm.tid == getpid() &&
+ strcmp(event->comm.comm, comm) == 0) {
+ if (switch_tracking->comm_seen[nr]) {
+ pr_debug("Duplicate comm event\n");
+ return -1;
+ }
+ switch_tracking->comm_seen[nr] = 1;
+ pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
+ return 1;
+ }
+ return 0;
+}
+
+static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
+{
+ int i, nr = cpu + 1;
+
+ if (cpu < 0)
+ return -1;
+
+ if (!switch_tracking->tids) {
+ switch_tracking->tids = calloc(nr, sizeof(pid_t));
+ if (!switch_tracking->tids)
+ return -1;
+ for (i = 0; i < nr; i++)
+ switch_tracking->tids[i] = -1;
+ switch_tracking->nr_tids = nr;
+ return 0;
+ }
+
+ if (cpu >= switch_tracking->nr_tids) {
+ void *addr;
+
+ addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
+ if (!addr)
+ return -1;
+ switch_tracking->tids = addr;
+ for (i = switch_tracking->nr_tids; i < nr; i++)
+ switch_tracking->tids[i] = -1;
+ switch_tracking->nr_tids = nr;
+ return 0;
+ }
+
+ return 0;
+}
+
+static int process_sample_event(struct perf_evlist *evlist,
+ union perf_event *event,
+ struct switch_tracking *switch_tracking)
+{
+ struct perf_sample sample;
+ struct perf_evsel *evsel;
+ pid_t next_tid, prev_tid;
+ int cpu, err;
+
+ if (perf_evlist__parse_sample(evlist, event, &sample)) {
+ pr_debug("perf_evlist__parse_sample failed\n");
+ return -1;
+ }
+
+ evsel = perf_evlist__id2evsel(evlist, sample.id);
+ if (evsel == switch_tracking->switch_evsel) {
+ next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
+ prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
+ cpu = sample.cpu;
+ pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
+ cpu, prev_tid, next_tid);
+ err = check_cpu(switch_tracking, cpu);
+ if (err)
+ return err;
+ /*
+ * Check for no missing sched_switch events i.e. that the
+ * evsel->system_wide flag has worked.
+ */
+ if (switch_tracking->tids[cpu] != -1 &&
+ switch_tracking->tids[cpu] != prev_tid) {
+ pr_debug("Missing sched_switch events\n");
+ return -1;
+ }
+ switch_tracking->tids[cpu] = next_tid;
+ }
+
+ if (evsel == switch_tracking->cycles_evsel) {
+ pr_debug3("cycles event\n");
+ if (!switch_tracking->comm_seen[0])
+ switch_tracking->cycles_before_comm_1 = 1;
+ if (switch_tracking->comm_seen[1] &&
+ !switch_tracking->comm_seen[2])
+ switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
+ if (switch_tracking->comm_seen[3])
+ switch_tracking->cycles_after_comm_4 = 1;
+ }
+
+ return 0;
+}
+
+static int process_event(struct perf_evlist *evlist, union perf_event *event,
+ struct switch_tracking *switch_tracking)
+{
+ if (event->header.type == PERF_RECORD_SAMPLE)
+ return process_sample_event(evlist, event, switch_tracking);
+
+ if (event->header.type == PERF_RECORD_COMM) {
+ int err, done = 0;
+
+ err = check_comm(switch_tracking, event, "Test COMM 1", 0);
+ if (err < 0)
+ return -1;
+ done += err;
+ err = check_comm(switch_tracking, event, "Test COMM 2", 1);
+ if (err < 0)
+ return -1;
+ done += err;
+ err = check_comm(switch_tracking, event, "Test COMM 3", 2);
+ if (err < 0)
+ return -1;
+ done += err;
+ err = check_comm(switch_tracking, event, "Test COMM 4", 3);
+ if (err < 0)
+ return -1;
+ done += err;
+ if (done != 1) {
+ pr_debug("Unexpected comm event\n");
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+struct event_node {
+ struct list_head list;
+ union perf_event *event;
+ u64 event_time;
+};
+
+static int add_event(struct perf_evlist *evlist, struct list_head *events,
+ union perf_event *event)
+{
+ struct perf_sample sample;
+ struct event_node *node;
+
+ node = malloc(sizeof(struct event_node));
+ if (!node) {
+ pr_debug("malloc failed\n");
+ return -1;
+ }
+ node->event = event;
+ list_add(&node->list, events);
+
+ if (perf_evlist__parse_sample(evlist, event, &sample)) {
+ pr_debug("perf_evlist__parse_sample failed\n");
+ return -1;
+ }
+
+ if (!sample.time) {
+ pr_debug("event with no time\n");
+ return -1;
+ }
+
+ node->event_time = sample.time;
+
+ return 0;
+}
+
+static void free_event_nodes(struct list_head *events)
+{
+ struct event_node *node;
+
+ while (!list_empty(events)) {
+ node = list_entry(events->next, struct event_node, list);
+ list_del(&node->list);
+ free(node);
+ }
+}
+
+static int compar(const void *a, const void *b)
+{
+ const struct event_node *nodea = a;
+ const struct event_node *nodeb = b;
+ s64 cmp = nodea->event_time - nodeb->event_time;
+
+ return cmp;
+}
+
+static int process_events(struct perf_evlist *evlist,
+ struct switch_tracking *switch_tracking)
+{
+ union perf_event *event;
+ unsigned pos, cnt = 0;
+ LIST_HEAD(events);
+ struct event_node *events_array, *node;
+ int i, ret;
+
+ for (i = 0; i < evlist->nr_mmaps; i++) {
+ while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
+ cnt += 1;
+ ret = add_event(evlist, &events, event);
+ perf_evlist__mmap_consume(evlist, i);
+ if (ret < 0)
+ goto out_free_nodes;
+ }
+ }
+
+ events_array = calloc(cnt, sizeof(struct event_node));
+ if (!events_array) {
+ pr_debug("calloc failed\n");
+ ret = -1;
+ goto out_free_nodes;
+ }
+
+ pos = 0;
+ list_for_each_entry(node, &events, list)
+ events_array[pos++] = *node;
+
+ qsort(events_array, cnt, sizeof(struct event_node), compar);
+
+ for (pos = 0; pos < cnt; pos++) {
+ ret = process_event(evlist, events_array[pos].event,
+ switch_tracking);
+ if (ret < 0)
+ goto out_free;
+ }
+
+ ret = 0;
+out_free:
+ pr_debug("%u events recorded\n", cnt);
+ free(events_array);
+out_free_nodes:
+ free_event_nodes(&events);
+ return ret;
+}
+
+/**
+ * test__switch_tracking - test using sched_switch and tracking events.
+ *
+ * This function implements a test that checks that sched_switch events and
+ * tracking events can be recorded for a workload (current process) using the
+ * evsel->system_wide and evsel->tracking flags (respectively) with other events
+ * sometimes enabled or disabled.
+ */
+int test__switch_tracking(void)
+{
+ const char *sched_switch = "sched:sched_switch";
+ struct switch_tracking switch_tracking = { .tids = NULL, };
+ struct record_opts opts = {
+ .mmap_pages = UINT_MAX,
+ .user_freq = UINT_MAX,
+ .user_interval = ULLONG_MAX,
+ .freq = 4000,
+ .target = {
+ .uses_mmap = true,
+ },
+ };
+ struct thread_map *threads = NULL;
+ struct cpu_map *cpus = NULL;
+ struct perf_evlist *evlist = NULL;
+ struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
+ struct perf_evsel *switch_evsel, *tracking_evsel;
+ const char *comm;
+ int err = -1;
+
+ threads = thread_map__new(-1, getpid(), UINT_MAX);
+ if (!threads) {
+ pr_debug("thread_map__new failed!\n");
+ goto out_err;
+ }
+
+ cpus = cpu_map__new(NULL);
+ if (!cpus) {
+ pr_debug("cpu_map__new failed!\n");
+ goto out_err;
+ }
+
+ evlist = perf_evlist__new();
+ if (!evlist) {
+ pr_debug("perf_evlist__new failed!\n");
+ goto out_err;
+ }
+
+ perf_evlist__set_maps(evlist, cpus, threads);
+
+ /* First event */
+ err = parse_events(evlist, "cpu-clock:u");
+ if (err) {
+ pr_debug("Failed to parse event dummy:u\n");
+ goto out_err;
+ }
+
+ cpu_clocks_evsel = perf_evlist__last(evlist);
+
+ /* Second event */
+ err = parse_events(evlist, "cycles:u");
+ if (err) {
+ pr_debug("Failed to parse event cycles:u\n");
+ goto out_err;
+ }
+
+ cycles_evsel = perf_evlist__last(evlist);
+
+ /* Third event */
+ if (!perf_evlist__can_select_event(evlist, sched_switch)) {
+ fprintf(stderr, " (no sched_switch)");
+ err = 0;
+ goto out;
+ }
+
+ err = parse_events(evlist, sched_switch);
+ if (err) {
+ pr_debug("Failed to parse event %s\n", sched_switch);
+ goto out_err;
+ }
+
+ switch_evsel = perf_evlist__last(evlist);
+
+ perf_evsel__set_sample_bit(switch_evsel, CPU);
+ perf_evsel__set_sample_bit(switch_evsel, TIME);
+
+ switch_evsel->system_wide = true;
+ switch_evsel->no_aux_samples = true;
+ switch_evsel->immediate = true;
+
+ /* Test moving an event to the front */
+ if (cycles_evsel == perf_evlist__first(evlist)) {
+ pr_debug("cycles event already at front");
+ goto out_err;
+ }
+ perf_evlist__to_front(evlist, cycles_evsel);
+ if (cycles_evsel != perf_evlist__first(evlist)) {
+ pr_debug("Failed to move cycles event to front");
+ goto out_err;
+ }
+
+ perf_evsel__set_sample_bit(cycles_evsel, CPU);
+ perf_evsel__set_sample_bit(cycles_evsel, TIME);
+
+ /* Fourth event */
+ err = parse_events(evlist, "dummy:u");
+ if (err) {
+ pr_debug("Failed to parse event dummy:u\n");
+ goto out_err;
+ }
+
+ tracking_evsel = perf_evlist__last(evlist);
+
+ perf_evlist__set_tracking_event(evlist, tracking_evsel);
+
+ tracking_evsel->attr.freq = 0;
+ tracking_evsel->attr.sample_period = 1;
+
+ perf_evsel__set_sample_bit(tracking_evsel, TIME);
+
+ /* Config events */
+ perf_evlist__config(evlist, &opts);
+
+ /* Check moved event is still at the front */
+ if (cycles_evsel != perf_evlist__first(evlist)) {
+ pr_debug("Front event no longer at front");
+ goto out_err;
+ }
+
+ /* Check tracking event is tracking */
+ if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
+ pr_debug("Tracking event not tracking\n");
+ goto out_err;
+ }
+
+ /* Check non-tracking events are not tracking */
+ evlist__for_each(evlist, evsel) {
+ if (evsel != tracking_evsel) {
+ if (evsel->attr.mmap || evsel->attr.comm) {
+ pr_debug("Non-tracking event is tracking\n");
+ goto out_err;
+ }
+ }
+ }
+
+ if (perf_evlist__open(evlist) < 0) {
+ fprintf(stderr, " (not supported)");
+ err = 0;
+ goto out;
+ }
+
+ err = perf_evlist__mmap(evlist, UINT_MAX, false);
+ if (err) {
+ pr_debug("perf_evlist__mmap failed!\n");
+ goto out_err;
+ }
+
+ perf_evlist__enable(evlist);
+
+ err = perf_evlist__disable_event(evlist, cpu_clocks_evsel);
+ if (err) {
+ pr_debug("perf_evlist__disable_event failed!\n");
+ goto out_err;
+ }
+
+ err = spin_sleep();
+ if (err) {
+ pr_debug("spin_sleep failed!\n");
+ goto out_err;
+ }
+
+ comm = "Test COMM 1";
+ err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
+ if (err) {
+ pr_debug("PR_SET_NAME failed!\n");
+ goto out_err;
+ }
+
+ err = perf_evlist__disable_event(evlist, cycles_evsel);
+ if (err) {
+ pr_debug("perf_evlist__disable_event failed!\n");
+ goto out_err;
+ }
+
+ comm = "Test COMM 2";
+ err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
+ if (err) {
+ pr_debug("PR_SET_NAME failed!\n");
+ goto out_err;
+ }
+
+ err = spin_sleep();
+ if (err) {
+ pr_debug("spin_sleep failed!\n");
+ goto out_err;
+ }
+
+ comm = "Test COMM 3";
+ err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
+ if (err) {
+ pr_debug("PR_SET_NAME failed!\n");
+ goto out_err;
+ }
+
+ err = perf_evlist__enable_event(evlist, cycles_evsel);
+ if (err) {
+ pr_debug("perf_evlist__disable_event failed!\n");
+ goto out_err;
+ }
+
+ comm = "Test COMM 4";
+ err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
+ if (err) {
+ pr_debug("PR_SET_NAME failed!\n");
+ goto out_err;
+ }
+
+ err = spin_sleep();
+ if (err) {
+ pr_debug("spin_sleep failed!\n");
+ goto out_err;
+ }
+
+ perf_evlist__disable(evlist);
+
+ switch_tracking.switch_evsel = switch_evsel;
+ switch_tracking.cycles_evsel = cycles_evsel;
+
+ err = process_events(evlist, &switch_tracking);
+
+ zfree(&switch_tracking.tids);
+
+ if (err)
+ goto out_err;
+
+ /* Check all 4 comm events were seen i.e. that evsel->tracking works */
+ if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
+ !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
+ pr_debug("Missing comm events\n");
+ goto out_err;
+ }
+
+ /* Check cycles event got enabled */
+ if (!switch_tracking.cycles_before_comm_1) {
+ pr_debug("Missing cycles events\n");
+ goto out_err;
+ }
+
+ /* Check cycles event got disabled */
+ if (switch_tracking.cycles_between_comm_2_and_comm_3) {
+ pr_debug("cycles events even though event was disabled\n");
+ goto out_err;
+ }
+
+ /* Check cycles event got enabled again */
+ if (!switch_tracking.cycles_after_comm_4) {
+ pr_debug("Missing cycles events\n");
+ goto out_err;
+ }
+out:
+ if (evlist) {
+ perf_evlist__disable(evlist);
+ perf_evlist__delete(evlist);
+ } else {
+ cpu_map__delete(cpus);
+ thread_map__delete(threads);
+ }
+
+ return err;
+
+out_err:
+ err = -1;
+ goto out;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index ed64790..be8be10 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -48,6 +48,7 @@ int test__mmap_thread_lookup(void);
int test__thread_mg_share(void);
int test__hists_output(void);
int test__hists_cumulate(void);
+int test__switch_tracking(void);

#if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
#ifdef HAVE_DWARF_UNWIND_SUPPORT
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