summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/bpf_counter_cgroup.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/perf/util/bpf_counter_cgroup.c')
-rw-r--r--tools/perf/util/bpf_counter_cgroup.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
new file mode 100644
index 000000000..1c82377ed
--- /dev/null
+++ b/tools/perf/util/bpf_counter_cgroup.c
@@ -0,0 +1,295 @@
+// 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;
+ int i, j;
+ struct perf_cpu cpu;
+ 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;
+ }
+
+ perf_cpu_map__for_each_cpu(cpu, i, evlist->core.all_cpus) {
+ 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, evsel->core.cpus, -1);
+ if (err == 0)
+ evsel->supported = true;
+
+ map_fd = bpf_map__fd(skel->maps.events);
+ perf_cpu_map__for_each_cpu(cpu, j, evsel->core.cpus) {
+ int fd = FD(evsel, j);
+ __u32 idx = evsel->core.idx * total_cpus + cpu.cpu;
+
+ bpf_map_update_elem(map_fd, &idx, &fd, BPF_ANY);
+ }
+
+ evsel->cgrp = leader_cgrp;
+ }
+
+ 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)
+{
+ struct perf_cpu cpu;
+ int idx;
+ int prog_fd = bpf_program__fd(skel->progs.trigger_read);
+
+ perf_cpu_map__for_each_cpu(cpu, idx, evlist->core.all_cpus)
+ bperf_trigger_reading(prog_fd, cpu.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 total_cpus = cpu__max_cpu().cpu;
+ struct perf_counts_values *counts;
+ struct bpf_perf_event_value *values;
+ int reading_map_fd, err = 0;
+
+ 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) {
+ __u32 idx = evsel->core.idx;
+ int i;
+ struct perf_cpu cpu;
+
+ 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;
+ }
+
+ perf_cpu_map__for_each_cpu(cpu, i, evsel->core.cpus) {
+ counts = perf_counts(evsel->counts, i, 0);
+ counts->val = values[cpu.cpu].counter;
+ counts->ena = values[cpu.cpu].enabled;
+ counts->run = values[cpu.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,
+};