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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
/* Copyright (c) 2021 Google */
#include <assert.h>
#include <limits.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <linux/err.h>
#include <linux/zalloc.h>
#include <linux/perf_event.h>
#include <api/fs/fs.h>
#include <perf/bpf_perf.h>
#include "affinity.h"
#include "bpf_counter.h"
#include "cgroup.h"
#include "counts.h"
#include "debug.h"
#include "evsel.h"
#include "evlist.h"
#include "target.h"
#include "cpumap.h"
#include "thread_map.h"
#include "bpf_skel/bperf_cgroup.skel.h"
static struct perf_event_attr cgrp_switch_attr = {
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CGROUP_SWITCHES,
.size = sizeof(cgrp_switch_attr),
.sample_period = 1,
.disabled = 1,
};
static struct evsel *cgrp_switch;
static struct bperf_cgroup_bpf *skel;
#define FD(evt, cpu) (*(int *)xyarray__entry(evt->core.fd, cpu, 0))
static int bperf_load_program(struct evlist *evlist)
{
struct bpf_link *link;
struct evsel *evsel;
struct cgroup *cgrp, *leader_cgrp;
__u32 i, cpu;
__u32 nr_cpus = evlist->core.all_cpus->nr;
int total_cpus = cpu__max_cpu().cpu;
int map_size, map_fd;
int prog_fd, err;
skel = bperf_cgroup_bpf__open();
if (!skel) {
pr_err("Failed to open cgroup skeleton\n");
return -1;
}
skel->rodata->num_cpus = total_cpus;
skel->rodata->num_events = evlist->core.nr_entries / nr_cgroups;
BUG_ON(evlist->core.nr_entries % nr_cgroups != 0);
/* we need one copy of events per cpu for reading */
map_size = total_cpus * evlist->core.nr_entries / nr_cgroups;
bpf_map__set_max_entries(skel->maps.events, map_size);
bpf_map__set_max_entries(skel->maps.cgrp_idx, nr_cgroups);
/* previous result is saved in a per-cpu array */
map_size = evlist->core.nr_entries / nr_cgroups;
bpf_map__set_max_entries(skel->maps.prev_readings, map_size);
/* cgroup result needs all events (per-cpu) */
map_size = evlist->core.nr_entries;
bpf_map__set_max_entries(skel->maps.cgrp_readings, map_size);
set_max_rlimit();
err = bperf_cgroup_bpf__load(skel);
if (err) {
pr_err("Failed to load cgroup skeleton\n");
goto out;
}
if (cgroup_is_v2("perf_event") > 0)
skel->bss->use_cgroup_v2 = 1;
err = -1;
cgrp_switch = evsel__new(&cgrp_switch_attr);
if (evsel__open_per_cpu(cgrp_switch, evlist->core.all_cpus, -1) < 0) {
pr_err("Failed to open cgroup switches event\n");
goto out;
}
for (i = 0; i < nr_cpus; i++) {
link = bpf_program__attach_perf_event(skel->progs.on_cgrp_switch,
FD(cgrp_switch, i));
if (IS_ERR(link)) {
pr_err("Failed to attach cgroup program\n");
err = PTR_ERR(link);
goto out;
}
}
/*
* Update cgrp_idx map from cgroup-id to event index.
*/
cgrp = NULL;
i = 0;
evlist__for_each_entry(evlist, evsel) {
if (cgrp == NULL || evsel->cgrp == leader_cgrp) {
leader_cgrp = evsel->cgrp;
evsel->cgrp = NULL;
/* open single copy of the events w/o cgroup */
err = evsel__open_per_cpu(evsel, evlist->core.all_cpus, -1);
if (err) {
pr_err("Failed to open first cgroup events\n");
goto out;
}
map_fd = bpf_map__fd(skel->maps.events);
for (cpu = 0; cpu < nr_cpus; cpu++) {
int fd = FD(evsel, cpu);
__u32 idx = evsel->core.idx * total_cpus +
evlist->core.all_cpus->map[cpu].cpu;
err = bpf_map_update_elem(map_fd, &idx, &fd,
BPF_ANY);
if (err < 0) {
pr_err("Failed to update perf_event fd\n");
goto out;
}
}
evsel->cgrp = leader_cgrp;
}
evsel->supported = true;
if (evsel->cgrp == cgrp)
continue;
cgrp = evsel->cgrp;
if (read_cgroup_id(cgrp) < 0) {
pr_err("Failed to get cgroup id\n");
err = -1;
goto out;
}
map_fd = bpf_map__fd(skel->maps.cgrp_idx);
err = bpf_map_update_elem(map_fd, &cgrp->id, &i, BPF_ANY);
if (err < 0) {
pr_err("Failed to update cgroup index map\n");
goto out;
}
i++;
}
/*
* bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check
* whether the kernel support it
*/
prog_fd = bpf_program__fd(skel->progs.trigger_read);
err = bperf_trigger_reading(prog_fd, 0);
if (err) {
pr_warning("The kernel does not support test_run for raw_tp BPF programs.\n"
"Therefore, --for-each-cgroup might show inaccurate readings\n");
err = 0;
}
out:
return err;
}
static int bperf_cgrp__load(struct evsel *evsel,
struct target *target __maybe_unused)
{
static bool bperf_loaded = false;
evsel->bperf_leader_prog_fd = -1;
evsel->bperf_leader_link_fd = -1;
if (!bperf_loaded && bperf_load_program(evsel->evlist))
return -1;
bperf_loaded = true;
/* just to bypass bpf_counter_skip() */
evsel->follower_skel = (struct bperf_follower_bpf *)skel;
return 0;
}
static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,
int cpu __maybe_unused, int fd __maybe_unused)
{
/* nothing to do */
return 0;
}
/*
* trigger the leader prog on each cpu, so the cgrp_reading map could get
* the latest results.
*/
static int bperf_cgrp__sync_counters(struct evlist *evlist)
{
int i, cpu;
int nr_cpus = evlist->core.all_cpus->nr;
int prog_fd = bpf_program__fd(skel->progs.trigger_read);
for (i = 0; i < nr_cpus; i++) {
cpu = evlist->core.all_cpus->map[i].cpu;
bperf_trigger_reading(prog_fd, cpu);
}
return 0;
}
static int bperf_cgrp__enable(struct evsel *evsel)
{
if (evsel->core.idx)
return 0;
bperf_cgrp__sync_counters(evsel->evlist);
skel->bss->enabled = 1;
return 0;
}
static int bperf_cgrp__disable(struct evsel *evsel)
{
if (evsel->core.idx)
return 0;
bperf_cgrp__sync_counters(evsel->evlist);
skel->bss->enabled = 0;
return 0;
}
static int bperf_cgrp__read(struct evsel *evsel)
{
struct evlist *evlist = evsel->evlist;
int i, cpu, nr_cpus = evlist->core.all_cpus->nr;
int total_cpus = cpu__max_cpu().cpu;
struct perf_counts_values *counts;
struct bpf_perf_event_value *values;
int reading_map_fd, err = 0;
__u32 idx;
if (evsel->core.idx)
return 0;
bperf_cgrp__sync_counters(evsel->evlist);
values = calloc(total_cpus, sizeof(*values));
if (values == NULL)
return -ENOMEM;
reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings);
evlist__for_each_entry(evlist, evsel) {
idx = evsel->core.idx;
err = bpf_map_lookup_elem(reading_map_fd, &idx, values);
if (err) {
pr_err("bpf map lookup failed: idx=%u, event=%s, cgrp=%s\n",
idx, evsel__name(evsel), evsel->cgrp->name);
goto out;
}
for (i = 0; i < nr_cpus; i++) {
cpu = evlist->core.all_cpus->map[i].cpu;
counts = perf_counts(evsel->counts, i, 0);
counts->val = values[cpu].counter;
counts->ena = values[cpu].enabled;
counts->run = values[cpu].running;
}
}
out:
free(values);
return err;
}
static int bperf_cgrp__destroy(struct evsel *evsel)
{
if (evsel->core.idx)
return 0;
bperf_cgroup_bpf__destroy(skel);
evsel__delete(cgrp_switch); // it'll destroy on_switch progs too
return 0;
}
struct bpf_counter_ops bperf_cgrp_ops = {
.load = bperf_cgrp__load,
.enable = bperf_cgrp__enable,
.disable = bperf_cgrp__disable,
.read = bperf_cgrp__read,
.install_pe = bperf_cgrp__install_pe,
.destroy = bperf_cgrp__destroy,
};
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