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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /tools/perf/util/bpf_ftrace.c | |
parent | Initial commit. (diff) | |
download | linux-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.c | 154 |
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; +} |