// SPDX-License-Identifier: GPL-2.0
#include <sys/time.h>
#include <sys/prctl.h>
#include <errno.h>
#include <limits.h>
#include <time.h>
#include <stdlib.h>
#include <linux/zalloc.h>
#include <linux/err.h>
#include <perf/cpumap.h>
#include <perf/evlist.h>
#include <perf/mmap.h>
#include "debug.h"
#include "parse-events.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "record.h"
#include "tests.h"
#include "util/mmap.h"
#include "util/sample.h"
#include "pmus.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 evsel *switch_evsel;
struct 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 evlist *evlist,
union perf_event *event,
struct switch_tracking *switch_tracking)
{
struct perf_sample sample;
struct evsel *evsel;
pid_t next_tid, prev_tid;
int cpu, err;
if (evlist__parse_sample(evlist, event, &sample)) {
pr_debug("evlist__parse_sample failed\n");
return -1;
}
evsel = evlist__id2evsel(evlist, sample.id);
if (evsel == switch_tracking->switch_evsel) {
next_tid = evsel__intval(evsel, &sample, "next_pid");
prev_tid = 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->core.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 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 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 (evlist__parse_sample(evlist, event, &sample)) {
pr_debug("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_init(&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 evlist *evlist,
struct switch_tracking *switch_tracking)
{
union perf_event *event;
unsigned pos, cnt = 0;
LIST_HEAD(events);
struct event_node *events_array, *node;
struct mmap *md;
int i, ret;
for (i = 0; i < evlist->core.nr_mmaps; i++) {
md = &evlist->mmap[i];
if (perf_mmap__read_init(&md->core) < 0)
continue;
while ((event = perf_mmap__read_event(&md->core)) != NULL) {
cnt += 1;
ret = add_event(evlist, &events, event);
perf_mmap__consume(&md->core);
if (ret < 0)
goto out_free_nodes;
}
perf_mmap__read_done(&md->core);
}
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->core.system_wide and evsel->tracking flags (respectively) with other events
* sometimes enabled or disabled.
*/
static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
const char *sched_switch = "sched:sched_switch";
const char *cycles = "cycles:u";
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 perf_thread_map *threads = NULL;
struct perf_cpu_map *cpus = NULL;
struct evlist *evlist = NULL;
struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
struct 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 = perf_cpu_map__new_online_cpus();
if (!cpus) {
pr_debug("perf_cpu_map__new failed!\n");
goto out_err;
}
evlist = evlist__new();
if (!evlist) {
pr_debug("evlist__new failed!\n");
goto out_err;
}
perf_evlist__set_maps(&evlist->core, cpus, threads);
/* First event */
err = parse_event(evlist, "cpu-clock:u");
if (err) {
pr_debug("Failed to parse event dummy:u\n");
goto out_err;
}
cpu_clocks_evsel = evlist__last(evlist);
/* Second event */
err = parse_event(evlist, cycles);
if (err) {
pr_debug("Failed to parse event %s\n", cycles);
goto out_err;
}
cycles_evsel = evlist__last(evlist);
/* Third event */
if (!evlist__can_select_event(evlist, sched_switch)) {
pr_debug("No sched_switch\n");
err = 0;
goto out;
}
switch_evsel = evlist__add_sched_switch(evlist, true);
if (IS_ERR(switch_evsel)) {
err = PTR_ERR(switch_evsel);
pr_debug("Failed to create event %s\n", sched_switch);
goto out_err;
}
switch_evsel->immediate = true;
/* Test moving an event to the front */
if (cycles_evsel == evlist__first(evlist)) {
pr_debug("cycles event already at front");
goto out_err;
}
evlist__to_front(evlist, cycles_evsel);
if (cycles_evsel != evlist__first(evlist)) {
pr_debug("Failed to move cycles event to front");
goto out_err;
}
evsel__set_sample_bit(cycles_evsel, CPU);
evsel__set_sample_bit(cycles_evsel, TIME);
/* Fourth event */
err = parse_event(evlist, "dummy:u");
if (err) {
pr_debug("Failed to parse event dummy:u\n");
goto out_err;
}
tracking_evsel = evlist__last(evlist);
evlist__set_tracking_event(evlist, tracking_evsel);
tracking_evsel->core.attr.freq = 0;
tracking_evsel->core.attr.sample_period = 1;
evsel__set_sample_bit(tracking_evsel, TIME);
/* Config events */
evlist__config(evlist, &opts, NULL);
/* Check moved event is still at the front */
if (cycles_evsel != evlist__first(evlist)) {
pr_debug("Front event no longer at front");
goto out_err;
}
/* Check tracking event is tracking */
if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
pr_debug("Tracking event not tracking\n");
goto out_err;
}
/* Check non-tracking events are not tracking */
evlist__for_each_entry(evlist, evsel) {
if (evsel != tracking_evsel) {
if (evsel->core.attr.mmap || evsel->core.attr.comm) {
pr_debug("Non-tracking event is tracking\n");
goto out_err;
}
}
}
if (evlist__open(evlist) < 0) {
pr_debug("Not supported\n");
err = 0;
goto out;
}
err = evlist__mmap(evlist, UINT_MAX);
if (err) {
pr_debug("evlist__mmap failed!\n");
goto out_err;
}
evlist__enable(evlist);
err = evsel__disable(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 = evsel__disable(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 = evsel__enable(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;
}
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) {
evlist__disable(evlist);
evlist__delete(evlist);
}
perf_cpu_map__put(cpus);
perf_thread_map__put(threads);
return err;
out_err:
err = -1;
goto out;
}
DEFINE_SUITE("Track with sched_switch", switch_tracking);
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