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kernel/tools/perf/util/bpf_counter.c

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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Facebook */
#include <assert.h>
#include <limits.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/time.h>
#include <linux/err.h>
#include <linux/zalloc.h>
#include <api/fs/fs.h>
#include <perf/bpf_perf.h>
#include "bpf_counter.h"
#include "bpf-utils.h"
#include "counts.h"
#include "debug.h"
#include "evsel.h"
#include "evlist.h"
#include "target.h"
#include "cgroup.h"
#include "cpumap.h"
#include "thread_map.h"
#include "bpf_skel/bpf_prog_profiler.skel.h"
#include "bpf_skel/bperf_u.h"
#include "bpf_skel/bperf_leader.skel.h"
#include "bpf_skel/bperf_follower.skel.h"
#define ATTR_MAP_SIZE 16
static inline void *u64_to_ptr(__u64 ptr)
{
return (void *)(unsigned long)ptr;
}
static struct bpf_counter *bpf_counter_alloc(void)
{
struct bpf_counter *counter;
counter = zalloc(sizeof(*counter));
if (counter)
INIT_LIST_HEAD(&counter->list);
return counter;
}
static int bpf_program_profiler__destroy(struct evsel *evsel)
{
struct bpf_counter *counter, *tmp;
list_for_each_entry_safe(counter, tmp,
&evsel->bpf_counter_list, list) {
list_del_init(&counter->list);
bpf_prog_profiler_bpf__destroy(counter->skel);
free(counter);
}
assert(list_empty(&evsel->bpf_counter_list));
return 0;
}
static char *bpf_target_prog_name(int tgt_fd)
{
struct bpf_func_info *func_info;
struct perf_bpil *info_linear;
const struct btf_type *t;
struct btf *btf = NULL;
char *name = NULL;
info_linear = get_bpf_prog_info_linear(tgt_fd, 1UL << PERF_BPIL_FUNC_INFO);
if (IS_ERR_OR_NULL(info_linear)) {
pr_debug("failed to get info_linear for prog FD %d\n", tgt_fd);
return NULL;
}
if (info_linear->info.btf_id == 0) {
pr_debug("prog FD %d doesn't have valid btf\n", tgt_fd);
goto out;
}
btf = btf__load_from_kernel_by_id(info_linear->info.btf_id);
if (libbpf_get_error(btf)) {
pr_debug("failed to load btf for prog FD %d\n", tgt_fd);
goto out;
}
func_info = u64_to_ptr(info_linear->info.func_info);
t = btf__type_by_id(btf, func_info[0].type_id);
if (!t) {
pr_debug("btf %d doesn't have type %d\n",
info_linear->info.btf_id, func_info[0].type_id);
goto out;
}
name = strdup(btf__name_by_offset(btf, t->name_off));
out:
btf__free(btf);
free(info_linear);
return name;
}
static int bpf_program_profiler_load_one(struct evsel *evsel, u32 prog_id)
{
struct bpf_prog_profiler_bpf *skel;
struct bpf_counter *counter;
struct bpf_program *prog;
char *prog_name = NULL;
int prog_fd;
int err;
prog_fd = bpf_prog_get_fd_by_id(prog_id);
if (prog_fd < 0) {
pr_err("Failed to open fd for bpf prog %u\n", prog_id);
return -1;
}
counter = bpf_counter_alloc();
if (!counter) {
close(prog_fd);
return -1;
}
skel = bpf_prog_profiler_bpf__open();
if (!skel) {
pr_err("Failed to open bpf skeleton\n");
goto err_out;
}
skel->rodata->num_cpu = evsel__nr_cpus(evsel);
bpf_map__set_max_entries(skel->maps.events, evsel__nr_cpus(evsel));
bpf_map__set_max_entries(skel->maps.fentry_readings, 1);
bpf_map__set_max_entries(skel->maps.accum_readings, 1);
prog_name = bpf_target_prog_name(prog_fd);
if (!prog_name) {
pr_err("Failed to get program name for bpf prog %u. Does it have BTF?\n", prog_id);
goto err_out;
}
bpf_object__for_each_program(prog, skel->obj) {
err = bpf_program__set_attach_target(prog, prog_fd, prog_name);
if (err) {
pr_err("bpf_program__set_attach_target failed.\n"
"Does bpf prog %u have BTF?\n", prog_id);
goto err_out;
}
}
set_max_rlimit();
err = bpf_prog_profiler_bpf__load(skel);
if (err) {
pr_err("bpf_prog_profiler_bpf__load failed\n");
goto err_out;
}
assert(skel != NULL);
counter->skel = skel;
list_add(&counter->list, &evsel->bpf_counter_list);
free(prog_name);
close(prog_fd);
return 0;
err_out:
bpf_prog_profiler_bpf__destroy(skel);
free(prog_name);
free(counter);
close(prog_fd);
return -1;
}
static int bpf_program_profiler__load(struct evsel *evsel, struct target *target)
{
char *bpf_str, *bpf_str_, *tok, *saveptr = NULL, *p;
u32 prog_id;
int ret;
bpf_str_ = bpf_str = strdup(target->bpf_str);
if (!bpf_str)
return -1;
while ((tok = strtok_r(bpf_str, ",", &saveptr)) != NULL) {
prog_id = strtoul(tok, &p, 10);
if (prog_id == 0 || prog_id == UINT_MAX ||
(*p != '\0' && *p != ',')) {
pr_err("Failed to parse bpf prog ids %s\n",
target->bpf_str);
free(bpf_str_);
return -1;
}
ret = bpf_program_profiler_load_one(evsel, prog_id);
if (ret) {
bpf_program_profiler__destroy(evsel);
free(bpf_str_);
return -1;
}
bpf_str = NULL;
}
free(bpf_str_);
return 0;
}
static int bpf_program_profiler__enable(struct evsel *evsel)
{
struct bpf_counter *counter;
int ret;
list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
assert(counter->skel != NULL);
ret = bpf_prog_profiler_bpf__attach(counter->skel);
if (ret) {
bpf_program_profiler__destroy(evsel);
return ret;
}
}
return 0;
}
static int bpf_program_profiler__disable(struct evsel *evsel)
{
struct bpf_counter *counter;
list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
assert(counter->skel != NULL);
bpf_prog_profiler_bpf__detach(counter->skel);
}
return 0;
}
static int bpf_program_profiler__read(struct evsel *evsel)
{
// BPF_MAP_TYPE_PERCPU_ARRAY uses /sys/devices/system/cpu/possible
// Sometimes possible > online, like on a Ryzen 3900X that has 24
// threads but its possible showed 0-31 -acme
int num_cpu_bpf = libbpf_num_possible_cpus();
struct bpf_perf_event_value values[num_cpu_bpf];
struct bpf_counter *counter;
struct perf_counts_values *counts;
int reading_map_fd;
__u32 key = 0;
int err, idx, bpf_cpu;
if (list_empty(&evsel->bpf_counter_list))
return -EAGAIN;
perf_cpu_map__for_each_idx(idx, evsel__cpus(evsel)) {
counts = perf_counts(evsel->counts, idx, 0);
counts->val = 0;
counts->ena = 0;
counts->run = 0;
}
list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
struct bpf_prog_profiler_bpf *skel = counter->skel;
assert(skel != NULL);
reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
err = bpf_map_lookup_elem(reading_map_fd, &key, values);
if (err) {
pr_err("failed to read value\n");
return err;
}
for (bpf_cpu = 0; bpf_cpu < num_cpu_bpf; bpf_cpu++) {
idx = perf_cpu_map__idx(evsel__cpus(evsel),
(struct perf_cpu){.cpu = bpf_cpu});
if (idx == -1)
continue;
counts = perf_counts(evsel->counts, idx, 0);
counts->val += values[bpf_cpu].counter;
counts->ena += values[bpf_cpu].enabled;
counts->run += values[bpf_cpu].running;
}
}
return 0;
}
static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx,
int fd)
{
struct bpf_prog_profiler_bpf *skel;
struct bpf_counter *counter;
int ret;
list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
skel = counter->skel;
assert(skel != NULL);
ret = bpf_map_update_elem(bpf_map__fd(skel->maps.events),
&cpu_map_idx, &fd, BPF_ANY);
if (ret)
return ret;
}
return 0;
}
struct bpf_counter_ops bpf_program_profiler_ops = {
.load = bpf_program_profiler__load,
.enable = bpf_program_profiler__enable,
.disable = bpf_program_profiler__disable,
.read = bpf_program_profiler__read,
.destroy = bpf_program_profiler__destroy,
.install_pe = bpf_program_profiler__install_pe,
};
static bool bperf_attr_map_compatible(int attr_map_fd)
{
struct bpf_map_info map_info = {0};
__u32 map_info_len = sizeof(map_info);
int err;
err = bpf_obj_get_info_by_fd(attr_map_fd, &map_info, &map_info_len);
if (err)
return false;
return (map_info.key_size == sizeof(struct perf_event_attr)) &&
(map_info.value_size == sizeof(struct perf_event_attr_map_entry));
}
static int bperf_lock_attr_map(struct target *target)
{
char path[PATH_MAX];
int map_fd, err;
if (target->attr_map) {
scnprintf(path, PATH_MAX, "%s", target->attr_map);
} else {
scnprintf(path, PATH_MAX, "%s/fs/bpf/%s", sysfs__mountpoint(),
BPF_PERF_DEFAULT_ATTR_MAP_PATH);
}
if (access(path, F_OK)) {
map_fd = bpf_map_create(BPF_MAP_TYPE_HASH, NULL,
sizeof(struct perf_event_attr),
sizeof(struct perf_event_attr_map_entry),
ATTR_MAP_SIZE, NULL);
if (map_fd < 0)
return -1;
err = bpf_obj_pin(map_fd, path);
if (err) {
/* someone pinned the map in parallel? */
close(map_fd);
map_fd = bpf_obj_get(path);
if (map_fd < 0)
return -1;
}
} else {
map_fd = bpf_obj_get(path);
if (map_fd < 0)
return -1;
}
if (!bperf_attr_map_compatible(map_fd)) {
close(map_fd);
return -1;
}
err = flock(map_fd, LOCK_EX);
if (err) {
close(map_fd);
return -1;
}
return map_fd;
}
static int bperf_check_target(struct evsel *evsel,
struct target *target,
enum bperf_filter_type *filter_type,
__u32 *filter_entry_cnt)
{
if (evsel->core.leader->nr_members > 1) {
pr_err("bpf managed perf events do not yet support groups.\n");
return -1;
}
/* determine filter type based on target */
if (target->system_wide) {
*filter_type = BPERF_FILTER_GLOBAL;
*filter_entry_cnt = 1;
} else if (target->cpu_list) {
*filter_type = BPERF_FILTER_CPU;
*filter_entry_cnt = perf_cpu_map__nr(evsel__cpus(evsel));
} else if (target->tid) {
*filter_type = BPERF_FILTER_PID;
*filter_entry_cnt = perf_thread_map__nr(evsel->core.threads);
} else if (target->pid || evsel->evlist->workload.pid != -1) {
*filter_type = BPERF_FILTER_TGID;
*filter_entry_cnt = perf_thread_map__nr(evsel->core.threads);
} else {
pr_err("bpf managed perf events do not yet support these targets.\n");
return -1;
}
return 0;
}
static struct perf_cpu_map *all_cpu_map;
static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
struct perf_event_attr_map_entry *entry)
{
struct bperf_leader_bpf *skel = bperf_leader_bpf__open();
int link_fd, diff_map_fd, err;
struct bpf_link *link = NULL;
if (!skel) {
pr_err("Failed to open leader skeleton\n");
return -1;
}
bpf_map__set_max_entries(skel->maps.events, libbpf_num_possible_cpus());
err = bperf_leader_bpf__load(skel);
if (err) {
pr_err("Failed to load leader skeleton\n");
goto out;
}
link = bpf_program__attach(skel->progs.on_switch);
if (IS_ERR(link)) {
pr_err("Failed to attach leader program\n");
err = PTR_ERR(link);
goto out;
}
link_fd = bpf_link__fd(link);
diff_map_fd = bpf_map__fd(skel->maps.diff_readings);
entry->link_id = bpf_link_get_id(link_fd);
entry->diff_map_id = bpf_map_get_id(diff_map_fd);
err = bpf_map_update_elem(attr_map_fd, &evsel->core.attr, entry, BPF_ANY);
assert(err == 0);
evsel->bperf_leader_link_fd = bpf_link_get_fd_by_id(entry->link_id);
assert(evsel->bperf_leader_link_fd >= 0);
/*
* save leader_skel for install_pe, which is called within
* following evsel__open_per_cpu call
*/
evsel->leader_skel = skel;
evsel__open_per_cpu(evsel, all_cpu_map, -1);
out:
bperf_leader_bpf__destroy(skel);
bpf_link__destroy(link);
return err;
}
static int bperf__load(struct evsel *evsel, struct target *target)
{
struct perf_event_attr_map_entry entry = {0xffffffff, 0xffffffff};
int attr_map_fd, diff_map_fd = -1, err;
enum bperf_filter_type filter_type;
__u32 filter_entry_cnt, i;
if (bperf_check_target(evsel, target, &filter_type, &filter_entry_cnt))
return -1;
if (!all_cpu_map) {
all_cpu_map = perf_cpu_map__new_online_cpus();
if (!all_cpu_map)
return -1;
}
evsel->bperf_leader_prog_fd = -1;
evsel->bperf_leader_link_fd = -1;
/*
* Step 1: hold a fd on the leader program and the bpf_link, if
* the program is not already gone, reload the program.
* Use flock() to ensure exclusive access to the perf_event_attr
* map.
*/
attr_map_fd = bperf_lock_attr_map(target);
if (attr_map_fd < 0) {
pr_err("Failed to lock perf_event_attr map\n");
return -1;
}
err = bpf_map_lookup_elem(attr_map_fd, &evsel->core.attr, &entry);
if (err) {
err = bpf_map_update_elem(attr_map_fd, &evsel->core.attr, &entry, BPF_ANY);
if (err)
goto out;
}
evsel->bperf_leader_link_fd = bpf_link_get_fd_by_id(entry.link_id);
if (evsel->bperf_leader_link_fd < 0 &&
bperf_reload_leader_program(evsel, attr_map_fd, &entry)) {
err = -1;
goto out;
}
/*
* The bpf_link holds reference to the leader program, and the
* leader program holds reference to the maps. Therefore, if
* link_id is valid, diff_map_id should also be valid.
*/
evsel->bperf_leader_prog_fd = bpf_prog_get_fd_by_id(
bpf_link_get_prog_id(evsel->bperf_leader_link_fd));
assert(evsel->bperf_leader_prog_fd >= 0);
diff_map_fd = bpf_map_get_fd_by_id(entry.diff_map_id);
assert(diff_map_fd >= 0);
/*
* bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check
* whether the kernel support it
*/
err = bperf_trigger_reading(evsel->bperf_leader_prog_fd, 0);
if (err) {
pr_err("The kernel does not support test_run for raw_tp BPF programs.\n"
"Therefore, --use-bpf might show inaccurate readings\n");
goto out;
}
/* Step 2: load the follower skeleton */
evsel->follower_skel = bperf_follower_bpf__open();
if (!evsel->follower_skel) {
err = -1;
pr_err("Failed to open follower skeleton\n");
goto out;
}
/* attach fexit program to the leader program */
bpf_program__set_attach_target(evsel->follower_skel->progs.fexit_XXX,
evsel->bperf_leader_prog_fd, "on_switch");
/* connect to leader diff_reading map */
bpf_map__reuse_fd(evsel->follower_skel->maps.diff_readings, diff_map_fd);
/* set up reading map */
bpf_map__set_max_entries(evsel->follower_skel->maps.accum_readings,
filter_entry_cnt);
/* set up follower filter based on target */
bpf_map__set_max_entries(evsel->follower_skel->maps.filter,
filter_entry_cnt);
err = bperf_follower_bpf__load(evsel->follower_skel);
if (err) {
pr_err("Failed to load follower skeleton\n");
bperf_follower_bpf__destroy(evsel->follower_skel);
evsel->follower_skel = NULL;
goto out;
}
for (i = 0; i < filter_entry_cnt; i++) {
int filter_map_fd;
__u32 key;
if (filter_type == BPERF_FILTER_PID ||
filter_type == BPERF_FILTER_TGID)
key = perf_thread_map__pid(evsel->core.threads, i);
else if (filter_type == BPERF_FILTER_CPU)
key = perf_cpu_map__cpu(evsel->core.cpus, i).cpu;
else
break;
filter_map_fd = bpf_map__fd(evsel->follower_skel->maps.filter);
bpf_map_update_elem(filter_map_fd, &key, &i, BPF_ANY);
}
evsel->follower_skel->bss->type = filter_type;
err = bperf_follower_bpf__attach(evsel->follower_skel);
out:
if (err && evsel->bperf_leader_link_fd >= 0)
close(evsel->bperf_leader_link_fd);
if (err && evsel->bperf_leader_prog_fd >= 0)
close(evsel->bperf_leader_prog_fd);
if (diff_map_fd >= 0)
close(diff_map_fd);
flock(attr_map_fd, LOCK_UN);
close(attr_map_fd);
return err;
}
static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
{
struct bperf_leader_bpf *skel = evsel->leader_skel;
return bpf_map_update_elem(bpf_map__fd(skel->maps.events),
&cpu_map_idx, &fd, BPF_ANY);
}
/*
* trigger the leader prog on each cpu, so the accum_reading map could get
* the latest readings.
*/
static int bperf_sync_counters(struct evsel *evsel)
{
int num_cpu, i, cpu;
num_cpu = perf_cpu_map__nr(all_cpu_map);
for (i = 0; i < num_cpu; i++) {
cpu = perf_cpu_map__cpu(all_cpu_map, i).cpu;
bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu);
}
return 0;
}
static int bperf__enable(struct evsel *evsel)
{
evsel->follower_skel->bss->enabled = 1;
return 0;
}
static int bperf__disable(struct evsel *evsel)
{
evsel->follower_skel->bss->enabled = 0;
return 0;
}
static int bperf__read(struct evsel *evsel)
{
struct bperf_follower_bpf *skel = evsel->follower_skel;
__u32 num_cpu_bpf = cpu__max_cpu().cpu;
struct bpf_perf_event_value values[num_cpu_bpf];
struct perf_counts_values *counts;
int reading_map_fd, err = 0;
__u32 i;
int j;
bperf_sync_counters(evsel);
reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
for (i = 0; i < bpf_map__max_entries(skel->maps.accum_readings); i++) {
struct perf_cpu entry;
__u32 cpu;
err = bpf_map_lookup_elem(reading_map_fd, &i, values);
if (err)
goto out;
switch (evsel->follower_skel->bss->type) {
case BPERF_FILTER_GLOBAL:
assert(i == 0);
perf_cpu_map__for_each_cpu(entry, j, evsel__cpus(evsel)) {
counts = perf_counts(evsel->counts, j, 0);
counts->val = values[entry.cpu].counter;
counts->ena = values[entry.cpu].enabled;
counts->run = values[entry.cpu].running;
}
break;
case BPERF_FILTER_CPU:
cpu = perf_cpu_map__cpu(evsel__cpus(evsel), i).cpu;
assert(cpu >= 0);
counts = perf_counts(evsel->counts, i, 0);
counts->val = values[cpu].counter;
counts->ena = values[cpu].enabled;
counts->run = values[cpu].running;
break;
case BPERF_FILTER_PID:
case BPERF_FILTER_TGID:
counts = perf_counts(evsel->counts, 0, i);
counts->val = 0;
counts->ena = 0;
counts->run = 0;
for (cpu = 0; cpu < num_cpu_bpf; cpu++) {
counts->val += values[cpu].counter;
counts->ena += values[cpu].enabled;
counts->run += values[cpu].running;
}
break;
default:
break;
}
}
out:
return err;
}
static int bperf__destroy(struct evsel *evsel)
{
bperf_follower_bpf__destroy(evsel->follower_skel);
close(evsel->bperf_leader_prog_fd);
close(evsel->bperf_leader_link_fd);
return 0;
}
/*
* bperf: share hardware PMCs with BPF
*
* perf uses performance monitoring counters (PMC) to monitor system
* performance. The PMCs are limited hardware resources. For example,
* Intel CPUs have 3x fixed PMCs and 4x programmable PMCs per cpu.
*
* Modern data center systems use these PMCs in many different ways:
* system level monitoring, (maybe nested) container level monitoring, per
* process monitoring, profiling (in sample mode), etc. In some cases,
* there are more active perf_events than available hardware PMCs. To allow
* all perf_events to have a chance to run, it is necessary to do expensive
* time multiplexing of events.
*
* On the other hand, many monitoring tools count the common metrics
* (cycles, instructions). It is a waste to have multiple tools create
* multiple perf_events of "cycles" and occupy multiple PMCs.
*
* bperf tries to reduce such wastes by allowing multiple perf_events of
* "cycles" or "instructions" (at different scopes) to share PMUs. Instead
* of having each perf-stat session to read its own perf_events, bperf uses
* BPF programs to read the perf_events and aggregate readings to BPF maps.
* Then, the perf-stat session(s) reads the values from these BPF maps.
*
* ||
* shared progs and maps <- || -> per session progs and maps
* ||
* --------------- ||
* | perf_events | ||
* --------------- fexit || -----------------
* | --------||----> | follower prog |
* --------------- / || --- -----------------
* cs -> | leader prog |/ ||/ | |
* --> --------------- /|| -------------- ------------------
* / | | / || | filter map | | accum_readings |
* / ------------ ------------ || -------------- ------------------
* | | prev map | | diff map | || |
* | ------------ ------------ || |
* \ || |
* = \ ==================================================== | ============
* \ / user space
* \ /
* \ /
* BPF_PROG_TEST_RUN BPF_MAP_LOOKUP_ELEM
* \ /
* \ /
* \------ perf-stat ----------------------/
*
* The figure above shows the architecture of bperf. Note that the figure
* is divided into 3 regions: shared progs and maps (top left), per session
* progs and maps (top right), and user space (bottom).
*
* The leader prog is triggered on each context switch (cs). The leader
* prog reads perf_events and stores the difference (current_reading -
* previous_reading) to the diff map. For the same metric, e.g. "cycles",
* multiple perf-stat sessions share the same leader prog.
*
* Each perf-stat session creates a follower prog as fexit program to the
* leader prog. It is possible to attach up to BPF_MAX_TRAMP_PROGS (38)
* follower progs to the same leader prog. The follower prog checks current
* task and processor ID to decide whether to add the value from the diff
* map to its accumulated reading map (accum_readings).
*
* Finally, perf-stat user space reads the value from accum_reading map.
*
* Besides context switch, it is also necessary to trigger the leader prog
* before perf-stat reads the value. Otherwise, the accum_reading map may
* not have the latest reading from the perf_events. This is achieved by
* triggering the event via sys_bpf(BPF_PROG_TEST_RUN) to each CPU.
*
* Comment before the definition of struct perf_event_attr_map_entry
* describes how different sessions of perf-stat share information about
* the leader prog.
*/
struct bpf_counter_ops bperf_ops = {
.load = bperf__load,
.enable = bperf__enable,
.disable = bperf__disable,
.read = bperf__read,
.install_pe = bperf__install_pe,
.destroy = bperf__destroy,
};
extern struct bpf_counter_ops bperf_cgrp_ops;
static inline bool bpf_counter_skip(struct evsel *evsel)
{
return evsel->bpf_counter_ops == NULL;
}
int bpf_counter__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
{
if (bpf_counter_skip(evsel))
return 0;
return evsel->bpf_counter_ops->install_pe(evsel, cpu_map_idx, fd);
}
int bpf_counter__load(struct evsel *evsel, struct target *target)
{
if (target->bpf_str)
evsel->bpf_counter_ops = &bpf_program_profiler_ops;
else if (cgrp_event_expanded && target->use_bpf)
evsel->bpf_counter_ops = &bperf_cgrp_ops;
else if (target->use_bpf || evsel->bpf_counter ||
evsel__match_bpf_counter_events(evsel->name))
evsel->bpf_counter_ops = &bperf_ops;
if (evsel->bpf_counter_ops)
return evsel->bpf_counter_ops->load(evsel, target);
return 0;
}
int bpf_counter__enable(struct evsel *evsel)
{
if (bpf_counter_skip(evsel))
return 0;
return evsel->bpf_counter_ops->enable(evsel);
}
int bpf_counter__disable(struct evsel *evsel)
{
if (bpf_counter_skip(evsel))
return 0;
return evsel->bpf_counter_ops->disable(evsel);
}
int bpf_counter__read(struct evsel *evsel)
{
if (bpf_counter_skip(evsel))
return -EAGAIN;
return evsel->bpf_counter_ops->read(evsel);
}
void bpf_counter__destroy(struct evsel *evsel)
{
if (bpf_counter_skip(evsel))
return;
evsel->bpf_counter_ops->destroy(evsel);
evsel->bpf_counter_ops = NULL;
evsel->bpf_skel = NULL;
}
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