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#include <stdio.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <bpf/bpf.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/stat.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 = NULL;
if (!list_empty(&ftrace->filters)) {
if (!list_is_singular(&ftrace->filters)) {
pr_err("ERROR: Too many target functions.\n");
return -1;
}
func = list_first_entry(&ftrace->filters, struct filter_entry, list);
} else {
int count = 0;
struct list_head *pos;
list_for_each(pos, &ftrace->event_pair)
count++;
if (count != 2) {
pr_err("ERROR: Needs two target events.\n");
return -1;
}
}
skel = func_latency_bpf__open();
if (!skel) {
pr_err("Failed to open func latency skeleton\n");
return -1;
}
skel->rodata->bucket_range = ftrace->bucket_range;
skel->rodata->min_latency = ftrace->min_latency;
skel->rodata->bucket_num = ftrace->bucket_num;
if (ftrace->bucket_range && ftrace->bucket_num) {
bpf_map__set_max_entries(skel->maps.latency, ftrace->bucket_num);
}
/* 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);
skel->rodata->has_cpu = 1;
}
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);
skel->rodata->has_task = 1;
}
skel->rodata->use_nsec = ftrace->use_nsec;
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;
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;
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->min = INT64_MAX;
if (func) {
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;
}
} else {
struct filter_entry *event;
event = list_first_entry(&ftrace->event_pair, struct filter_entry, list);
skel->links.event_begin = bpf_program__attach_raw_tracepoint(skel->progs.event_begin,
event->name);
if (IS_ERR(skel->links.event_begin)) {
pr_err("Failed to attach first tracepoint program\n");
err = PTR_ERR(skel->links.event_begin);
goto out;
}
event = list_next_entry(event, list);
skel->links.event_end = bpf_program__attach_raw_tracepoint(skel->progs.event_end,
event->name);
if (IS_ERR(skel->links.event_end)) {
pr_err("Failed to attach second tracepoint program\n");
err = PTR_ERR(skel->links.event_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,
int buckets[], struct stats *stats)
{
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 < skel->rodata->bucket_num; 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];
}
if (skel->bss->count) {
stats->mean = skel->bss->total / skel->bss->count;
stats->n = skel->bss->count;
stats->max = skel->bss->max;
stats->min = skel->bss->min;
if (!ftrace->use_nsec) {
stats->mean /= 1000;
stats->max /= 1000;
stats->min /= 1000;
}
}
free(hist);
return 0;
}
int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused)
{
func_latency_bpf__destroy(skel);
return 0;
}
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