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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/perf/util/bpf_ftrace.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/bpf_ftrace.c')
-rw-r--r--tools/perf/util/bpf_ftrace.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_ftrace.c b/tools/perf/util/bpf_ftrace.c
new file mode 100644
index 000000000..7a4297d8f
--- /dev/null
+++ b/tools/perf/util/bpf_ftrace.c
@@ -0,0 +1,154 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <linux/err.h>
+
+#include "util/ftrace.h"
+#include "util/cpumap.h"
+#include "util/thread_map.h"
+#include "util/debug.h"
+#include "util/evlist.h"
+#include "util/bpf_counter.h"
+
+#include "util/bpf_skel/func_latency.skel.h"
+
+static struct func_latency_bpf *skel;
+
+int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
+{
+ int fd, err;
+ int i, ncpus = 1, ntasks = 1;
+ struct filter_entry *func;
+
+ if (!list_is_singular(&ftrace->filters)) {
+ pr_err("ERROR: %s target function(s).\n",
+ list_empty(&ftrace->filters) ? "No" : "Too many");
+ return -1;
+ }
+
+ func = list_first_entry(&ftrace->filters, struct filter_entry, list);
+
+ skel = func_latency_bpf__open();
+ if (!skel) {
+ pr_err("Failed to open func latency skeleton\n");
+ return -1;
+ }
+
+ /* don't need to set cpu filter for system-wide mode */
+ if (ftrace->target.cpu_list) {
+ ncpus = perf_cpu_map__nr(ftrace->evlist->core.user_requested_cpus);
+ bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
+ }
+
+ if (target__has_task(&ftrace->target) || target__none(&ftrace->target)) {
+ ntasks = perf_thread_map__nr(ftrace->evlist->core.threads);
+ bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
+ }
+
+ set_max_rlimit();
+
+ err = func_latency_bpf__load(skel);
+ if (err) {
+ pr_err("Failed to load func latency skeleton\n");
+ goto out;
+ }
+
+ if (ftrace->target.cpu_list) {
+ u32 cpu;
+ u8 val = 1;
+
+ skel->bss->has_cpu = 1;
+ fd = bpf_map__fd(skel->maps.cpu_filter);
+
+ for (i = 0; i < ncpus; i++) {
+ cpu = perf_cpu_map__cpu(ftrace->evlist->core.user_requested_cpus, i).cpu;
+ bpf_map_update_elem(fd, &cpu, &val, BPF_ANY);
+ }
+ }
+
+ if (target__has_task(&ftrace->target) || target__none(&ftrace->target)) {
+ u32 pid;
+ u8 val = 1;
+
+ skel->bss->has_task = 1;
+ fd = bpf_map__fd(skel->maps.task_filter);
+
+ for (i = 0; i < ntasks; i++) {
+ pid = perf_thread_map__pid(ftrace->evlist->core.threads, i);
+ bpf_map_update_elem(fd, &pid, &val, BPF_ANY);
+ }
+ }
+
+ skel->bss->use_nsec = ftrace->use_nsec;
+
+ skel->links.func_begin = bpf_program__attach_kprobe(skel->progs.func_begin,
+ false, func->name);
+ if (IS_ERR(skel->links.func_begin)) {
+ pr_err("Failed to attach fentry program\n");
+ err = PTR_ERR(skel->links.func_begin);
+ goto out;
+ }
+
+ skel->links.func_end = bpf_program__attach_kprobe(skel->progs.func_end,
+ true, func->name);
+ if (IS_ERR(skel->links.func_end)) {
+ pr_err("Failed to attach fexit program\n");
+ err = PTR_ERR(skel->links.func_end);
+ goto out;
+ }
+
+ /* XXX: we don't actually use this fd - just for poll() */
+ return open("/dev/null", O_RDONLY);
+
+out:
+ return err;
+}
+
+int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused)
+{
+ skel->bss->enabled = 1;
+ return 0;
+}
+
+int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused)
+{
+ skel->bss->enabled = 0;
+ return 0;
+}
+
+int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused,
+ int buckets[])
+{
+ int i, fd, err;
+ u32 idx;
+ u64 *hist;
+ int ncpus = cpu__max_cpu().cpu;
+
+ fd = bpf_map__fd(skel->maps.latency);
+
+ hist = calloc(ncpus, sizeof(*hist));
+ if (hist == NULL)
+ return -ENOMEM;
+
+ for (idx = 0; idx < NUM_BUCKET; idx++) {
+ err = bpf_map_lookup_elem(fd, &idx, hist);
+ if (err) {
+ buckets[idx] = 0;
+ continue;
+ }
+
+ for (i = 0; i < ncpus; i++)
+ buckets[idx] += hist[i];
+ }
+
+ free(hist);
+ return 0;
+}
+
+int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused)
+{
+ func_latency_bpf__destroy(skel);
+ return 0;
+}