linux/tools/perf/util/evlist.c
Arnaldo Carvalho de Melo f5e7150cd9 perf evlist: Expose perf_event_mlock_kb_in_pages() helper
When the user doesn't set --mmap-pages, perf_evlist__mmap() will do it
by reading the maximum possible for a non-root user from the
/proc/sys/kernel/perf_event_mlock_kb file.

Expose that function so that 'perf trace' can, for root users, to bump
mmap-pages to a higher value for root, based on the contents of this
proc file.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-xay69plylwibpb3l4isrpl1k@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-15 17:46:31 -03:00

1789 lines
41 KiB
C

/*
* Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
*
* Parts came from builtin-{top,stat,record}.c, see those files for further
* copyright notes.
*
* Released under the GPL v2. (and only v2, not any later version)
*/
#include "util.h"
#include <api/fs/fs.h>
#include <poll.h>
#include "cpumap.h"
#include "thread_map.h"
#include "target.h"
#include "evlist.h"
#include "evsel.h"
#include "debug.h"
#include <unistd.h>
#include "parse-events.h"
#include <subcmd/parse-options.h>
#include <sys/mman.h>
#include <linux/bitops.h>
#include <linux/hash.h>
#include <linux/log2.h>
#include <linux/err.h>
static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);
static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx);
#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
#define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
struct thread_map *threads)
{
int i;
for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
INIT_HLIST_HEAD(&evlist->heads[i]);
INIT_LIST_HEAD(&evlist->entries);
perf_evlist__set_maps(evlist, cpus, threads);
fdarray__init(&evlist->pollfd, 64);
evlist->workload.pid = -1;
}
struct perf_evlist *perf_evlist__new(void)
{
struct perf_evlist *evlist = zalloc(sizeof(*evlist));
if (evlist != NULL)
perf_evlist__init(evlist, NULL, NULL);
return evlist;
}
struct perf_evlist *perf_evlist__new_default(void)
{
struct perf_evlist *evlist = perf_evlist__new();
if (evlist && perf_evlist__add_default(evlist)) {
perf_evlist__delete(evlist);
evlist = NULL;
}
return evlist;
}
struct perf_evlist *perf_evlist__new_dummy(void)
{
struct perf_evlist *evlist = perf_evlist__new();
if (evlist && perf_evlist__add_dummy(evlist)) {
perf_evlist__delete(evlist);
evlist = NULL;
}
return evlist;
}
/**
* perf_evlist__set_id_pos - set the positions of event ids.
* @evlist: selected event list
*
* Events with compatible sample types all have the same id_pos
* and is_pos. For convenience, put a copy on evlist.
*/
void perf_evlist__set_id_pos(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist);
evlist->id_pos = first->id_pos;
evlist->is_pos = first->is_pos;
}
static void perf_evlist__update_id_pos(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel)
perf_evsel__calc_id_pos(evsel);
perf_evlist__set_id_pos(evlist);
}
static void perf_evlist__purge(struct perf_evlist *evlist)
{
struct perf_evsel *pos, *n;
evlist__for_each_safe(evlist, n, pos) {
list_del_init(&pos->node);
pos->evlist = NULL;
perf_evsel__delete(pos);
}
evlist->nr_entries = 0;
}
void perf_evlist__exit(struct perf_evlist *evlist)
{
zfree(&evlist->mmap);
fdarray__exit(&evlist->pollfd);
}
void perf_evlist__delete(struct perf_evlist *evlist)
{
perf_evlist__munmap(evlist);
perf_evlist__close(evlist);
cpu_map__put(evlist->cpus);
thread_map__put(evlist->threads);
evlist->cpus = NULL;
evlist->threads = NULL;
perf_evlist__purge(evlist);
perf_evlist__exit(evlist);
free(evlist);
}
static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
struct perf_evsel *evsel)
{
/*
* We already have cpus for evsel (via PMU sysfs) so
* keep it, if there's no target cpu list defined.
*/
if (!evsel->own_cpus || evlist->has_user_cpus) {
cpu_map__put(evsel->cpus);
evsel->cpus = cpu_map__get(evlist->cpus);
} else if (evsel->cpus != evsel->own_cpus) {
cpu_map__put(evsel->cpus);
evsel->cpus = cpu_map__get(evsel->own_cpus);
}
thread_map__put(evsel->threads);
evsel->threads = thread_map__get(evlist->threads);
}
static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel)
__perf_evlist__propagate_maps(evlist, evsel);
}
void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
{
entry->evlist = evlist;
list_add_tail(&entry->node, &evlist->entries);
entry->idx = evlist->nr_entries;
entry->tracking = !entry->idx;
if (!evlist->nr_entries++)
perf_evlist__set_id_pos(evlist);
__perf_evlist__propagate_maps(evlist, entry);
}
void perf_evlist__remove(struct perf_evlist *evlist, struct perf_evsel *evsel)
{
evsel->evlist = NULL;
list_del_init(&evsel->node);
evlist->nr_entries -= 1;
}
void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
struct list_head *list)
{
struct perf_evsel *evsel, *temp;
__evlist__for_each_safe(list, temp, evsel) {
list_del_init(&evsel->node);
perf_evlist__add(evlist, evsel);
}
}
void __perf_evlist__set_leader(struct list_head *list)
{
struct perf_evsel *evsel, *leader;
leader = list_entry(list->next, struct perf_evsel, node);
evsel = list_entry(list->prev, struct perf_evsel, node);
leader->nr_members = evsel->idx - leader->idx + 1;
__evlist__for_each(list, evsel) {
evsel->leader = leader;
}
}
void perf_evlist__set_leader(struct perf_evlist *evlist)
{
if (evlist->nr_entries) {
evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
__perf_evlist__set_leader(&evlist->entries);
}
}
void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr)
{
attr->precise_ip = 3;
while (attr->precise_ip != 0) {
int fd = sys_perf_event_open(attr, 0, -1, -1, 0);
if (fd != -1) {
close(fd);
break;
}
--attr->precise_ip;
}
}
int perf_evlist__add_default(struct perf_evlist *evlist)
{
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
struct perf_evsel *evsel;
event_attr_init(&attr);
perf_event_attr__set_max_precise_ip(&attr);
evsel = perf_evsel__new(&attr);
if (evsel == NULL)
goto error;
/* use asprintf() because free(evsel) assumes name is allocated */
if (asprintf(&evsel->name, "cycles%.*s",
attr.precise_ip ? attr.precise_ip + 1 : 0, ":ppp") < 0)
goto error_free;
perf_evlist__add(evlist, evsel);
return 0;
error_free:
perf_evsel__delete(evsel);
error:
return -ENOMEM;
}
int perf_evlist__add_dummy(struct perf_evlist *evlist)
{
struct perf_event_attr attr = {
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_DUMMY,
.size = sizeof(attr), /* to capture ABI version */
};
struct perf_evsel *evsel = perf_evsel__new(&attr);
if (evsel == NULL)
return -ENOMEM;
perf_evlist__add(evlist, evsel);
return 0;
}
static int perf_evlist__add_attrs(struct perf_evlist *evlist,
struct perf_event_attr *attrs, size_t nr_attrs)
{
struct perf_evsel *evsel, *n;
LIST_HEAD(head);
size_t i;
for (i = 0; i < nr_attrs; i++) {
evsel = perf_evsel__new_idx(attrs + i, evlist->nr_entries + i);
if (evsel == NULL)
goto out_delete_partial_list;
list_add_tail(&evsel->node, &head);
}
perf_evlist__splice_list_tail(evlist, &head);
return 0;
out_delete_partial_list:
__evlist__for_each_safe(&head, n, evsel)
perf_evsel__delete(evsel);
return -1;
}
int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
struct perf_event_attr *attrs, size_t nr_attrs)
{
size_t i;
for (i = 0; i < nr_attrs; i++)
event_attr_init(attrs + i);
return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
}
struct perf_evsel *
perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
if (evsel->attr.type == PERF_TYPE_TRACEPOINT &&
(int)evsel->attr.config == id)
return evsel;
}
return NULL;
}
struct perf_evsel *
perf_evlist__find_tracepoint_by_name(struct perf_evlist *evlist,
const char *name)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
if ((evsel->attr.type == PERF_TYPE_TRACEPOINT) &&
(strcmp(evsel->name, name) == 0))
return evsel;
}
return NULL;
}
int perf_evlist__add_newtp(struct perf_evlist *evlist,
const char *sys, const char *name, void *handler)
{
struct perf_evsel *evsel = perf_evsel__newtp(sys, name);
if (IS_ERR(evsel))
return -1;
evsel->handler = handler;
perf_evlist__add(evlist, evsel);
return 0;
}
static int perf_evlist__nr_threads(struct perf_evlist *evlist,
struct perf_evsel *evsel)
{
if (evsel->system_wide)
return 1;
else
return thread_map__nr(evlist->threads);
}
void perf_evlist__disable(struct perf_evlist *evlist)
{
struct perf_evsel *pos;
evlist__for_each(evlist, pos) {
if (!perf_evsel__is_group_leader(pos) || !pos->fd)
continue;
perf_evsel__disable(pos);
}
evlist->enabled = false;
}
void perf_evlist__enable(struct perf_evlist *evlist)
{
struct perf_evsel *pos;
evlist__for_each(evlist, pos) {
if (!perf_evsel__is_group_leader(pos) || !pos->fd)
continue;
perf_evsel__enable(pos);
}
evlist->enabled = true;
}
void perf_evlist__toggle_enable(struct perf_evlist *evlist)
{
(evlist->enabled ? perf_evlist__disable : perf_evlist__enable)(evlist);
}
static int perf_evlist__enable_event_cpu(struct perf_evlist *evlist,
struct perf_evsel *evsel, int cpu)
{
int thread, err;
int nr_threads = perf_evlist__nr_threads(evlist, evsel);
if (!evsel->fd)
return -EINVAL;
for (thread = 0; thread < nr_threads; thread++) {
err = ioctl(FD(evsel, cpu, thread),
PERF_EVENT_IOC_ENABLE, 0);
if (err)
return err;
}
return 0;
}
static int perf_evlist__enable_event_thread(struct perf_evlist *evlist,
struct perf_evsel *evsel,
int thread)
{
int cpu, err;
int nr_cpus = cpu_map__nr(evlist->cpus);
if (!evsel->fd)
return -EINVAL;
for (cpu = 0; cpu < nr_cpus; cpu++) {
err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
if (err)
return err;
}
return 0;
}
int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
struct perf_evsel *evsel, int idx)
{
bool per_cpu_mmaps = !cpu_map__empty(evlist->cpus);
if (per_cpu_mmaps)
return perf_evlist__enable_event_cpu(evlist, evsel, idx);
else
return perf_evlist__enable_event_thread(evlist, evsel, idx);
}
int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
{
int nr_cpus = cpu_map__nr(evlist->cpus);
int nr_threads = thread_map__nr(evlist->threads);
int nfds = 0;
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
if (evsel->system_wide)
nfds += nr_cpus;
else
nfds += nr_cpus * nr_threads;
}
if (fdarray__available_entries(&evlist->pollfd) < nfds &&
fdarray__grow(&evlist->pollfd, nfds) < 0)
return -ENOMEM;
return 0;
}
static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx)
{
int pos = fdarray__add(&evlist->pollfd, fd, POLLIN | POLLERR | POLLHUP);
/*
* Save the idx so that when we filter out fds POLLHUP'ed we can
* close the associated evlist->mmap[] entry.
*/
if (pos >= 0) {
evlist->pollfd.priv[pos].idx = idx;
fcntl(fd, F_SETFL, O_NONBLOCK);
}
return pos;
}
int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
{
return __perf_evlist__add_pollfd(evlist, fd, -1);
}
static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd)
{
struct perf_evlist *evlist = container_of(fda, struct perf_evlist, pollfd);
perf_evlist__mmap_put(evlist, fda->priv[fd].idx);
}
int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
{
return fdarray__filter(&evlist->pollfd, revents_and_mask,
perf_evlist__munmap_filtered);
}
int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
{
return fdarray__poll(&evlist->pollfd, timeout);
}
static void perf_evlist__id_hash(struct perf_evlist *evlist,
struct perf_evsel *evsel,
int cpu, int thread, u64 id)
{
int hash;
struct perf_sample_id *sid = SID(evsel, cpu, thread);
sid->id = id;
sid->evsel = evsel;
hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
hlist_add_head(&sid->node, &evlist->heads[hash]);
}
void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
int cpu, int thread, u64 id)
{
perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
evsel->id[evsel->ids++] = id;
}
int perf_evlist__id_add_fd(struct perf_evlist *evlist,
struct perf_evsel *evsel,
int cpu, int thread, int fd)
{
u64 read_data[4] = { 0, };
int id_idx = 1; /* The first entry is the counter value */
u64 id;
int ret;
ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
if (!ret)
goto add;
if (errno != ENOTTY)
return -1;
/* Legacy way to get event id.. All hail to old kernels! */
/*
* This way does not work with group format read, so bail
* out in that case.
*/
if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
return -1;
if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
read(fd, &read_data, sizeof(read_data)) == -1)
return -1;
if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
++id_idx;
if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
++id_idx;
id = read_data[id_idx];
add:
perf_evlist__id_add(evlist, evsel, cpu, thread, id);
return 0;
}
static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,
struct perf_evsel *evsel, int idx, int cpu,
int thread)
{
struct perf_sample_id *sid = SID(evsel, cpu, thread);
sid->idx = idx;
if (evlist->cpus && cpu >= 0)
sid->cpu = evlist->cpus->map[cpu];
else
sid->cpu = -1;
if (!evsel->system_wide && evlist->threads && thread >= 0)
sid->tid = thread_map__pid(evlist->threads, thread);
else
sid->tid = -1;
}
struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id)
{
struct hlist_head *head;
struct perf_sample_id *sid;
int hash;
hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
head = &evlist->heads[hash];
hlist_for_each_entry(sid, head, node)
if (sid->id == id)
return sid;
return NULL;
}
struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
{
struct perf_sample_id *sid;
if (evlist->nr_entries == 1 || !id)
return perf_evlist__first(evlist);
sid = perf_evlist__id2sid(evlist, id);
if (sid)
return sid->evsel;
if (!perf_evlist__sample_id_all(evlist))
return perf_evlist__first(evlist);
return NULL;
}
struct perf_evsel *perf_evlist__id2evsel_strict(struct perf_evlist *evlist,
u64 id)
{
struct perf_sample_id *sid;
if (!id)
return NULL;
sid = perf_evlist__id2sid(evlist, id);
if (sid)
return sid->evsel;
return NULL;
}
static int perf_evlist__event2id(struct perf_evlist *evlist,
union perf_event *event, u64 *id)
{
const u64 *array = event->sample.array;
ssize_t n;
n = (event->header.size - sizeof(event->header)) >> 3;
if (event->header.type == PERF_RECORD_SAMPLE) {
if (evlist->id_pos >= n)
return -1;
*id = array[evlist->id_pos];
} else {
if (evlist->is_pos > n)
return -1;
n -= evlist->is_pos;
*id = array[n];
}
return 0;
}
static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist,
union perf_event *event)
{
struct perf_evsel *first = perf_evlist__first(evlist);
struct hlist_head *head;
struct perf_sample_id *sid;
int hash;
u64 id;
if (evlist->nr_entries == 1)
return first;
if (!first->attr.sample_id_all &&
event->header.type != PERF_RECORD_SAMPLE)
return first;
if (perf_evlist__event2id(evlist, event, &id))
return NULL;
/* Synthesized events have an id of zero */
if (!id)
return first;
hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
head = &evlist->heads[hash];
hlist_for_each_entry(sid, head, node) {
if (sid->id == id)
return sid->evsel;
}
return NULL;
}
union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
{
struct perf_mmap *md = &evlist->mmap[idx];
u64 head;
u64 old = md->prev;
unsigned char *data = md->base + page_size;
union perf_event *event = NULL;
/*
* Check if event was unmapped due to a POLLHUP/POLLERR.
*/
if (!atomic_read(&md->refcnt))
return NULL;
head = perf_mmap__read_head(md);
if (evlist->overwrite) {
/*
* If we're further behind than half the buffer, there's a chance
* the writer will bite our tail and mess up the samples under us.
*
* If we somehow ended up ahead of the head, we got messed up.
*
* In either case, truncate and restart at head.
*/
int diff = head - old;
if (diff > md->mask / 2 || diff < 0) {
fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
/*
* head points to a known good entry, start there.
*/
old = head;
}
}
if (old != head) {
size_t size;
event = (union perf_event *)&data[old & md->mask];
size = event->header.size;
/*
* Event straddles the mmap boundary -- header should always
* be inside due to u64 alignment of output.
*/
if ((old & md->mask) + size != ((old + size) & md->mask)) {
unsigned int offset = old;
unsigned int len = min(sizeof(*event), size), cpy;
void *dst = md->event_copy;
do {
cpy = min(md->mask + 1 - (offset & md->mask), len);
memcpy(dst, &data[offset & md->mask], cpy);
offset += cpy;
dst += cpy;
len -= cpy;
} while (len);
event = (union perf_event *) md->event_copy;
}
old += size;
}
md->prev = old;
return event;
}
static bool perf_mmap__empty(struct perf_mmap *md)
{
return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base;
}
static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx)
{
atomic_inc(&evlist->mmap[idx].refcnt);
}
static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)
{
BUG_ON(atomic_read(&evlist->mmap[idx].refcnt) == 0);
if (atomic_dec_and_test(&evlist->mmap[idx].refcnt))
__perf_evlist__munmap(evlist, idx);
}
void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx)
{
struct perf_mmap *md = &evlist->mmap[idx];
if (!evlist->overwrite) {
u64 old = md->prev;
perf_mmap__write_tail(md, old);
}
if (atomic_read(&md->refcnt) == 1 && perf_mmap__empty(md))
perf_evlist__mmap_put(evlist, idx);
}
int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
struct auxtrace_mmap_params *mp __maybe_unused,
void *userpg __maybe_unused,
int fd __maybe_unused)
{
return 0;
}
void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused)
{
}
void __weak auxtrace_mmap_params__init(
struct auxtrace_mmap_params *mp __maybe_unused,
off_t auxtrace_offset __maybe_unused,
unsigned int auxtrace_pages __maybe_unused,
bool auxtrace_overwrite __maybe_unused)
{
}
void __weak auxtrace_mmap_params__set_idx(
struct auxtrace_mmap_params *mp __maybe_unused,
struct perf_evlist *evlist __maybe_unused,
int idx __maybe_unused,
bool per_cpu __maybe_unused)
{
}
static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx)
{
if (evlist->mmap[idx].base != NULL) {
munmap(evlist->mmap[idx].base, evlist->mmap_len);
evlist->mmap[idx].base = NULL;
atomic_set(&evlist->mmap[idx].refcnt, 0);
}
auxtrace_mmap__munmap(&evlist->mmap[idx].auxtrace_mmap);
}
void perf_evlist__munmap(struct perf_evlist *evlist)
{
int i;
if (evlist->mmap == NULL)
return;
for (i = 0; i < evlist->nr_mmaps; i++)
__perf_evlist__munmap(evlist, i);
zfree(&evlist->mmap);
}
static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
{
evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
if (cpu_map__empty(evlist->cpus))
evlist->nr_mmaps = thread_map__nr(evlist->threads);
evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
return evlist->mmap != NULL ? 0 : -ENOMEM;
}
struct mmap_params {
int prot;
int mask;
struct auxtrace_mmap_params auxtrace_mp;
};
static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
struct mmap_params *mp, int fd)
{
/*
* The last one will be done at perf_evlist__mmap_consume(), so that we
* make sure we don't prevent tools from consuming every last event in
* the ring buffer.
*
* I.e. we can get the POLLHUP meaning that the fd doesn't exist
* anymore, but the last events for it are still in the ring buffer,
* waiting to be consumed.
*
* Tools can chose to ignore this at their own discretion, but the
* evlist layer can't just drop it when filtering events in
* perf_evlist__filter_pollfd().
*/
atomic_set(&evlist->mmap[idx].refcnt, 2);
evlist->mmap[idx].prev = 0;
evlist->mmap[idx].mask = mp->mask;
evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot,
MAP_SHARED, fd, 0);
if (evlist->mmap[idx].base == MAP_FAILED) {
pr_debug2("failed to mmap perf event ring buffer, error %d\n",
errno);
evlist->mmap[idx].base = NULL;
return -1;
}
if (auxtrace_mmap__mmap(&evlist->mmap[idx].auxtrace_mmap,
&mp->auxtrace_mp, evlist->mmap[idx].base, fd))
return -1;
return 0;
}
static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
struct mmap_params *mp, int cpu,
int thread, int *output)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
int fd;
if (evsel->system_wide && thread)
continue;
fd = FD(evsel, cpu, thread);
if (*output == -1) {
*output = fd;
if (__perf_evlist__mmap(evlist, idx, mp, *output) < 0)
return -1;
} else {
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
return -1;
perf_evlist__mmap_get(evlist, idx);
}
/*
* The system_wide flag causes a selected event to be opened
* always without a pid. Consequently it will never get a
* POLLHUP, but it is used for tracking in combination with
* other events, so it should not need to be polled anyway.
* Therefore don't add it for polling.
*/
if (!evsel->system_wide &&
__perf_evlist__add_pollfd(evlist, fd, idx) < 0) {
perf_evlist__mmap_put(evlist, idx);
return -1;
}
if (evsel->attr.read_format & PERF_FORMAT_ID) {
if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
fd) < 0)
return -1;
perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
thread);
}
}
return 0;
}
static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist,
struct mmap_params *mp)
{
int cpu, thread;
int nr_cpus = cpu_map__nr(evlist->cpus);
int nr_threads = thread_map__nr(evlist->threads);
pr_debug2("perf event ring buffer mmapped per cpu\n");
for (cpu = 0; cpu < nr_cpus; cpu++) {
int output = -1;
auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, cpu,
true);
for (thread = 0; thread < nr_threads; thread++) {
if (perf_evlist__mmap_per_evsel(evlist, cpu, mp, cpu,
thread, &output))
goto out_unmap;
}
}
return 0;
out_unmap:
for (cpu = 0; cpu < nr_cpus; cpu++)
__perf_evlist__munmap(evlist, cpu);
return -1;
}
static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist,
struct mmap_params *mp)
{
int thread;
int nr_threads = thread_map__nr(evlist->threads);
pr_debug2("perf event ring buffer mmapped per thread\n");
for (thread = 0; thread < nr_threads; thread++) {
int output = -1;
auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, thread,
false);
if (perf_evlist__mmap_per_evsel(evlist, thread, mp, 0, thread,
&output))
goto out_unmap;
}
return 0;
out_unmap:
for (thread = 0; thread < nr_threads; thread++)
__perf_evlist__munmap(evlist, thread);
return -1;
}
unsigned long perf_event_mlock_kb_in_pages(void)
{
unsigned long pages;
int max;
if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
/*
* Pick a once upon a time good value, i.e. things look
* strange since we can't read a sysctl value, but lets not
* die yet...
*/
max = 512;
} else {
max -= (page_size / 1024);
}
pages = (max * 1024) / page_size;
if (!is_power_of_2(pages))
pages = rounddown_pow_of_two(pages);
return pages;
}
static size_t perf_evlist__mmap_size(unsigned long pages)
{
if (pages == UINT_MAX)
pages = perf_event_mlock_kb_in_pages();
else if (!is_power_of_2(pages))
return 0;
return (pages + 1) * page_size;
}
static long parse_pages_arg(const char *str, unsigned long min,
unsigned long max)
{
unsigned long pages, val;
static struct parse_tag tags[] = {
{ .tag = 'B', .mult = 1 },
{ .tag = 'K', .mult = 1 << 10 },
{ .tag = 'M', .mult = 1 << 20 },
{ .tag = 'G', .mult = 1 << 30 },
{ .tag = 0 },
};
if (str == NULL)
return -EINVAL;
val = parse_tag_value(str, tags);
if (val != (unsigned long) -1) {
/* we got file size value */
pages = PERF_ALIGN(val, page_size) / page_size;
} else {
/* we got pages count value */
char *eptr;
pages = strtoul(str, &eptr, 10);
if (*eptr != '\0')
return -EINVAL;
}
if (pages == 0 && min == 0) {
/* leave number of pages at 0 */
} else if (!is_power_of_2(pages)) {
/* round pages up to next power of 2 */
pages = roundup_pow_of_two(pages);
if (!pages)
return -EINVAL;
pr_info("rounding mmap pages size to %lu bytes (%lu pages)\n",
pages * page_size, pages);
}
if (pages > max)
return -EINVAL;
return pages;
}
int __perf_evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
{
unsigned long max = UINT_MAX;
long pages;
if (max > SIZE_MAX / page_size)
max = SIZE_MAX / page_size;
pages = parse_pages_arg(str, 1, max);
if (pages < 0) {
pr_err("Invalid argument for --mmap_pages/-m\n");
return -1;
}
*mmap_pages = pages;
return 0;
}
int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
int unset __maybe_unused)
{
return __perf_evlist__parse_mmap_pages(opt->value, str);
}
/**
* perf_evlist__mmap_ex - Create mmaps to receive events.
* @evlist: list of events
* @pages: map length in pages
* @overwrite: overwrite older events?
* @auxtrace_pages - auxtrace map length in pages
* @auxtrace_overwrite - overwrite older auxtrace data?
*
* If @overwrite is %false the user needs to signal event consumption using
* perf_mmap__write_tail(). Using perf_evlist__mmap_read() does this
* automatically.
*
* Similarly, if @auxtrace_overwrite is %false the user needs to signal data
* consumption using auxtrace_mmap__write_tail().
*
* Return: %0 on success, negative error code otherwise.
*/
int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
bool overwrite, unsigned int auxtrace_pages,
bool auxtrace_overwrite)
{
struct perf_evsel *evsel;
const struct cpu_map *cpus = evlist->cpus;
const struct thread_map *threads = evlist->threads;
struct mmap_params mp = {
.prot = PROT_READ | (overwrite ? 0 : PROT_WRITE),
};
if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
return -ENOMEM;
if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
return -ENOMEM;
evlist->overwrite = overwrite;
evlist->mmap_len = perf_evlist__mmap_size(pages);
pr_debug("mmap size %zuB\n", evlist->mmap_len);
mp.mask = evlist->mmap_len - page_size - 1;
auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len,
auxtrace_pages, auxtrace_overwrite);
evlist__for_each(evlist, evsel) {
if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
evsel->sample_id == NULL &&
perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
return -ENOMEM;
}
if (cpu_map__empty(cpus))
return perf_evlist__mmap_per_thread(evlist, &mp);
return perf_evlist__mmap_per_cpu(evlist, &mp);
}
int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
bool overwrite)
{
return perf_evlist__mmap_ex(evlist, pages, overwrite, 0, false);
}
int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
{
struct cpu_map *cpus;
struct thread_map *threads;
threads = thread_map__new_str(target->pid, target->tid, target->uid);
if (!threads)
return -1;
if (target__uses_dummy_map(target))
cpus = cpu_map__dummy_new();
else
cpus = cpu_map__new(target->cpu_list);
if (!cpus)
goto out_delete_threads;
evlist->has_user_cpus = !!target->cpu_list;
perf_evlist__set_maps(evlist, cpus, threads);
return 0;
out_delete_threads:
thread_map__put(threads);
return -1;
}
void perf_evlist__set_maps(struct perf_evlist *evlist, struct cpu_map *cpus,
struct thread_map *threads)
{
/*
* Allow for the possibility that one or another of the maps isn't being
* changed i.e. don't put it. Note we are assuming the maps that are
* being applied are brand new and evlist is taking ownership of the
* original reference count of 1. If that is not the case it is up to
* the caller to increase the reference count.
*/
if (cpus != evlist->cpus) {
cpu_map__put(evlist->cpus);
evlist->cpus = cpu_map__get(cpus);
}
if (threads != evlist->threads) {
thread_map__put(evlist->threads);
evlist->threads = thread_map__get(threads);
}
perf_evlist__propagate_maps(evlist);
}
void __perf_evlist__set_sample_bit(struct perf_evlist *evlist,
enum perf_event_sample_format bit)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel)
__perf_evsel__set_sample_bit(evsel, bit);
}
void __perf_evlist__reset_sample_bit(struct perf_evlist *evlist,
enum perf_event_sample_format bit)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel)
__perf_evsel__reset_sample_bit(evsel, bit);
}
int perf_evlist__apply_filters(struct perf_evlist *evlist, struct perf_evsel **err_evsel)
{
struct perf_evsel *evsel;
int err = 0;
const int ncpus = cpu_map__nr(evlist->cpus),
nthreads = thread_map__nr(evlist->threads);
evlist__for_each(evlist, evsel) {
if (evsel->filter == NULL)
continue;
/*
* filters only work for tracepoint event, which doesn't have cpu limit.
* So evlist and evsel should always be same.
*/
err = perf_evsel__apply_filter(evsel, ncpus, nthreads, evsel->filter);
if (err) {
*err_evsel = evsel;
break;
}
}
return err;
}
int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
{
struct perf_evsel *evsel;
int err = 0;
evlist__for_each(evlist, evsel) {
if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
continue;
err = perf_evsel__set_filter(evsel, filter);
if (err)
break;
}
return err;
}
int perf_evlist__set_filter_pids(struct perf_evlist *evlist, size_t npids, pid_t *pids)
{
char *filter;
int ret = -1;
size_t i;
for (i = 0; i < npids; ++i) {
if (i == 0) {
if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
return -1;
} else {
char *tmp;
if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
goto out_free;
free(filter);
filter = tmp;
}
}
ret = perf_evlist__set_filter(evlist, filter);
out_free:
free(filter);
return ret;
}
int perf_evlist__set_filter_pid(struct perf_evlist *evlist, pid_t pid)
{
return perf_evlist__set_filter_pids(evlist, 1, &pid);
}
bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
{
struct perf_evsel *pos;
if (evlist->nr_entries == 1)
return true;
if (evlist->id_pos < 0 || evlist->is_pos < 0)
return false;
evlist__for_each(evlist, pos) {
if (pos->id_pos != evlist->id_pos ||
pos->is_pos != evlist->is_pos)
return false;
}
return true;
}
u64 __perf_evlist__combined_sample_type(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
if (evlist->combined_sample_type)
return evlist->combined_sample_type;
evlist__for_each(evlist, evsel)
evlist->combined_sample_type |= evsel->attr.sample_type;
return evlist->combined_sample_type;
}
u64 perf_evlist__combined_sample_type(struct perf_evlist *evlist)
{
evlist->combined_sample_type = 0;
return __perf_evlist__combined_sample_type(evlist);
}
u64 perf_evlist__combined_branch_type(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
u64 branch_type = 0;
evlist__for_each(evlist, evsel)
branch_type |= evsel->attr.branch_sample_type;
return branch_type;
}
bool perf_evlist__valid_read_format(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
u64 read_format = first->attr.read_format;
u64 sample_type = first->attr.sample_type;
evlist__for_each(evlist, pos) {
if (read_format != pos->attr.read_format)
return false;
}
/* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
if ((sample_type & PERF_SAMPLE_READ) &&
!(read_format & PERF_FORMAT_ID)) {
return false;
}
return true;
}
u64 perf_evlist__read_format(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist);
return first->attr.read_format;
}
u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist);
struct perf_sample *data;
u64 sample_type;
u16 size = 0;
if (!first->attr.sample_id_all)
goto out;
sample_type = first->attr.sample_type;
if (sample_type & PERF_SAMPLE_TID)
size += sizeof(data->tid) * 2;
if (sample_type & PERF_SAMPLE_TIME)
size += sizeof(data->time);
if (sample_type & PERF_SAMPLE_ID)
size += sizeof(data->id);
if (sample_type & PERF_SAMPLE_STREAM_ID)
size += sizeof(data->stream_id);
if (sample_type & PERF_SAMPLE_CPU)
size += sizeof(data->cpu) * 2;
if (sample_type & PERF_SAMPLE_IDENTIFIER)
size += sizeof(data->id);
out:
return size;
}
bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
evlist__for_each_continue(evlist, pos) {
if (first->attr.sample_id_all != pos->attr.sample_id_all)
return false;
}
return true;
}
bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
{
struct perf_evsel *first = perf_evlist__first(evlist);
return first->attr.sample_id_all;
}
void perf_evlist__set_selected(struct perf_evlist *evlist,
struct perf_evsel *evsel)
{
evlist->selected = evsel;
}
void perf_evlist__close(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
int ncpus = cpu_map__nr(evlist->cpus);
int nthreads = thread_map__nr(evlist->threads);
int n;
evlist__for_each_reverse(evlist, evsel) {
n = evsel->cpus ? evsel->cpus->nr : ncpus;
perf_evsel__close(evsel, n, nthreads);
}
}
static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist)
{
struct cpu_map *cpus;
struct thread_map *threads;
int err = -ENOMEM;
/*
* Try reading /sys/devices/system/cpu/online to get
* an all cpus map.
*
* FIXME: -ENOMEM is the best we can do here, the cpu_map
* code needs an overhaul to properly forward the
* error, and we may not want to do that fallback to a
* default cpu identity map :-\
*/
cpus = cpu_map__new(NULL);
if (!cpus)
goto out;
threads = thread_map__new_dummy();
if (!threads)
goto out_put;
perf_evlist__set_maps(evlist, cpus, threads);
out:
return err;
out_put:
cpu_map__put(cpus);
goto out;
}
int perf_evlist__open(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
int err;
/*
* Default: one fd per CPU, all threads, aka systemwide
* as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
*/
if (evlist->threads == NULL && evlist->cpus == NULL) {
err = perf_evlist__create_syswide_maps(evlist);
if (err < 0)
goto out_err;
}
perf_evlist__update_id_pos(evlist);
evlist__for_each(evlist, evsel) {
err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
if (err < 0)
goto out_err;
}
return 0;
out_err:
perf_evlist__close(evlist);
errno = -err;
return err;
}
int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *target,
const char *argv[], bool pipe_output,
void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
{
int child_ready_pipe[2], go_pipe[2];
char bf;
if (pipe(child_ready_pipe) < 0) {
perror("failed to create 'ready' pipe");
return -1;
}
if (pipe(go_pipe) < 0) {
perror("failed to create 'go' pipe");
goto out_close_ready_pipe;
}
evlist->workload.pid = fork();
if (evlist->workload.pid < 0) {
perror("failed to fork");
goto out_close_pipes;
}
if (!evlist->workload.pid) {
int ret;
if (pipe_output)
dup2(2, 1);
signal(SIGTERM, SIG_DFL);
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
/*
* Tell the parent we're ready to go
*/
close(child_ready_pipe[1]);
/*
* Wait until the parent tells us to go.
*/
ret = read(go_pipe[0], &bf, 1);
/*
* The parent will ask for the execvp() to be performed by
* writing exactly one byte, in workload.cork_fd, usually via
* perf_evlist__start_workload().
*
* For cancelling the workload without actually running it,
* the parent will just close workload.cork_fd, without writing
* anything, i.e. read will return zero and we just exit()
* here.
*/
if (ret != 1) {
if (ret == -1)
perror("unable to read pipe");
exit(ret);
}
execvp(argv[0], (char **)argv);
if (exec_error) {
union sigval val;
val.sival_int = errno;
if (sigqueue(getppid(), SIGUSR1, val))
perror(argv[0]);
} else
perror(argv[0]);
exit(-1);
}
if (exec_error) {
struct sigaction act = {
.sa_flags = SA_SIGINFO,
.sa_sigaction = exec_error,
};
sigaction(SIGUSR1, &act, NULL);
}
if (target__none(target)) {
if (evlist->threads == NULL) {
fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
__func__, __LINE__);
goto out_close_pipes;
}
thread_map__set_pid(evlist->threads, 0, evlist->workload.pid);
}
close(child_ready_pipe[1]);
close(go_pipe[0]);
/*
* wait for child to settle
*/
if (read(child_ready_pipe[0], &bf, 1) == -1) {
perror("unable to read pipe");
goto out_close_pipes;
}
fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
evlist->workload.cork_fd = go_pipe[1];
close(child_ready_pipe[0]);
return 0;
out_close_pipes:
close(go_pipe[0]);
close(go_pipe[1]);
out_close_ready_pipe:
close(child_ready_pipe[0]);
close(child_ready_pipe[1]);
return -1;
}
int perf_evlist__start_workload(struct perf_evlist *evlist)
{
if (evlist->workload.cork_fd > 0) {
char bf = 0;
int ret;
/*
* Remove the cork, let it rip!
*/
ret = write(evlist->workload.cork_fd, &bf, 1);
if (ret < 0)
perror("enable to write to pipe");
close(evlist->workload.cork_fd);
return ret;
}
return 0;
}
int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
struct perf_sample *sample)
{
struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
if (!evsel)
return -EFAULT;
return perf_evsel__parse_sample(evsel, event, sample);
}
size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
{
struct perf_evsel *evsel;
size_t printed = 0;
evlist__for_each(evlist, evsel) {
printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
perf_evsel__name(evsel));
}
return printed + fprintf(fp, "\n");
}
int perf_evlist__strerror_open(struct perf_evlist *evlist,
int err, char *buf, size_t size)
{
int printed, value;
char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
switch (err) {
case EACCES:
case EPERM:
printed = scnprintf(buf, size,
"Error:\t%s.\n"
"Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
value = perf_event_paranoid();
printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
if (value >= 2) {
printed += scnprintf(buf + printed, size - printed,
"For your workloads it needs to be <= 1\nHint:\t");
}
printed += scnprintf(buf + printed, size - printed,
"For system wide tracing it needs to be set to -1.\n");
printed += scnprintf(buf + printed, size - printed,
"Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
"Hint:\tThe current value is %d.", value);
break;
case EINVAL: {
struct perf_evsel *first = perf_evlist__first(evlist);
int max_freq;
if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
goto out_default;
if (first->attr.sample_freq < (u64)max_freq)
goto out_default;
printed = scnprintf(buf, size,
"Error:\t%s.\n"
"Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
"Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
emsg, max_freq, first->attr.sample_freq);
break;
}
default:
out_default:
scnprintf(buf, size, "%s", emsg);
break;
}
return 0;
}
int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size)
{
char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user, printed = 0;
switch (err) {
case EPERM:
sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
printed += scnprintf(buf + printed, size - printed,
"Error:\t%s.\n"
"Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
"Hint:\tTried using %zd kB.\n",
emsg, pages_max_per_user, pages_attempted);
if (pages_attempted >= pages_max_per_user) {
printed += scnprintf(buf + printed, size - printed,
"Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
pages_max_per_user + pages_attempted);
}
printed += scnprintf(buf + printed, size - printed,
"Hint:\tTry using a smaller -m/--mmap-pages value.");
break;
default:
scnprintf(buf, size, "%s", emsg);
break;
}
return 0;
}
void perf_evlist__to_front(struct perf_evlist *evlist,
struct perf_evsel *move_evsel)
{
struct perf_evsel *evsel, *n;
LIST_HEAD(move);
if (move_evsel == perf_evlist__first(evlist))
return;
evlist__for_each_safe(evlist, n, evsel) {
if (evsel->leader == move_evsel->leader)
list_move_tail(&evsel->node, &move);
}
list_splice(&move, &evlist->entries);
}
void perf_evlist__set_tracking_event(struct perf_evlist *evlist,
struct perf_evsel *tracking_evsel)
{
struct perf_evsel *evsel;
if (tracking_evsel->tracking)
return;
evlist__for_each(evlist, evsel) {
if (evsel != tracking_evsel)
evsel->tracking = false;
}
tracking_evsel->tracking = true;
}
struct perf_evsel *
perf_evlist__find_evsel_by_str(struct perf_evlist *evlist,
const char *str)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
if (!evsel->name)
continue;
if (strcmp(str, evsel->name) == 0)
return evsel;
}
return NULL;
}