Re: [PATCH v5 1/6] perf cpumap: Switch to using perf_cpu_map API
From: Namhyung Kim
Date: Wed May 04 2022 - 14:18:48 EST
Hi Ian,
On Mon, May 2, 2022 at 9:18 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> Switch some raw accesses to the cpu map to using the library API. This
> can help with reference count checking. Some BPF cases switch from index
> to CPU for consistency, this shouldn't matter as the CPU map is full.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Thanks,
Namhyung
> ---
> tools/perf/builtin-record.c | 13 +++++----
> tools/perf/util/bpf_counter_cgroup.c | 42 +++++++++++++---------------
> 2 files changed, 26 insertions(+), 29 deletions(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 069825c48d40..a5cf6a99d67f 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1011,7 +1011,7 @@ static int record__thread_data_init_maps(struct record_thread *thread_data, stru
>
> for (m = 0, tm = 0; m < nr_mmaps && tm < thread_data->nr_mmaps; m++) {
> if (cpu_map__is_dummy(cpus) ||
> - test_bit(cpus->map[m].cpu, thread_data->mask->maps.bits)) {
> + test_bit(perf_cpu_map__cpu(cpus, m).cpu, thread_data->mask->maps.bits)) {
> if (thread_data->maps) {
> thread_data->maps[tm] = &mmap[m];
> pr_debug2("thread_data[%p]: cpu%d: maps[%d] -> mmap[%d]\n",
> @@ -3331,13 +3331,14 @@ struct option *record_options = __record_options;
>
> static void record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cpu_map *cpus)
> {
> - int c;
> + struct perf_cpu cpu;
> + int idx;
>
> if (cpu_map__is_dummy(cpus))
> return;
>
> - for (c = 0; c < cpus->nr; c++)
> - set_bit(cpus->map[c].cpu, mask->bits);
> + perf_cpu_map__for_each_cpu(cpu, idx, cpus)
> + set_bit(cpu.cpu, mask->bits);
> }
>
> static int record__mmap_cpu_mask_init_spec(struct mmap_cpu_mask *mask, const char *mask_spec)
> @@ -3404,8 +3405,8 @@ static int record__init_thread_cpu_masks(struct record *rec, struct perf_cpu_map
> pr_debug("nr_threads: %d\n", rec->nr_threads);
>
> for (t = 0; t < rec->nr_threads; t++) {
> - set_bit(cpus->map[t].cpu, rec->thread_masks[t].maps.bits);
> - set_bit(cpus->map[t].cpu, rec->thread_masks[t].affinity.bits);
> + set_bit(perf_cpu_map__cpu(cpus, t).cpu, rec->thread_masks[t].maps.bits);
> + set_bit(perf_cpu_map__cpu(cpus, t).cpu, rec->thread_masks[t].affinity.bits);
> if (verbose) {
> pr_debug("thread_masks[%d]: ", t);
> mmap_cpu_mask__scnprintf(&rec->thread_masks[t].maps, "maps");
> diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
> index ac60c08e8e2a..63b9db657442 100644
> --- a/tools/perf/util/bpf_counter_cgroup.c
> +++ b/tools/perf/util/bpf_counter_cgroup.c
> @@ -46,8 +46,8 @@ 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 i, j;
> + struct perf_cpu cpu;
> int total_cpus = cpu__max_cpu().cpu;
> int map_size, map_fd;
> int prog_fd, err;
> @@ -93,9 +93,9 @@ static int bperf_load_program(struct evlist *evlist)
> goto out;
> }
>
> - for (i = 0; i < nr_cpus; i++) {
> + 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));
> + FD(cgrp_switch, cpu.cpu));
> if (IS_ERR(link)) {
> pr_err("Failed to attach cgroup program\n");
> err = PTR_ERR(link);
> @@ -122,10 +122,9 @@ static int bperf_load_program(struct evlist *evlist)
> }
>
> 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;
> + perf_cpu_map__for_each_cpu(cpu, j, evlist->core.all_cpus) {
> + int fd = FD(evsel, cpu.cpu);
> + __u32 idx = evsel->core.idx * total_cpus + cpu.cpu;
>
> err = bpf_map_update_elem(map_fd, &idx, &fd,
> BPF_ANY);
> @@ -207,14 +206,12 @@ static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,
> */
> static int bperf_cgrp__sync_counters(struct evlist *evlist)
> {
> - int i, cpu;
> - int nr_cpus = evlist->core.all_cpus->nr;
> + struct perf_cpu cpu;
> + int idx;
> 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);
> - }
> + perf_cpu_map__for_each_cpu(cpu, idx, evlist->core.all_cpus)
> + bperf_trigger_reading(prog_fd, cpu.cpu);
>
> return 0;
> }
> @@ -244,12 +241,10 @@ static int bperf_cgrp__disable(struct evsel *evsel)
> 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;
> @@ -263,7 +258,10 @@ static int bperf_cgrp__read(struct evsel *evsel)
> reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings);
>
> evlist__for_each_entry(evlist, evsel) {
> - idx = evsel->core.idx;
> + __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",
> @@ -271,13 +269,11 @@ static int bperf_cgrp__read(struct evsel *evsel)
> goto out;
> }
>
> - for (i = 0; i < nr_cpus; i++) {
> - cpu = evlist->core.all_cpus->map[i].cpu;
> -
> + perf_cpu_map__for_each_cpu(cpu, i, evlist->core.all_cpus) {
> counts = perf_counts(evsel->counts, i, 0);
> - counts->val = values[cpu].counter;
> - counts->ena = values[cpu].enabled;
> - counts->run = values[cpu].running;
> + counts->val = values[cpu.cpu].counter;
> + counts->ena = values[cpu.cpu].enabled;
> + counts->run = values[cpu.cpu].running;
> }
> }
>
> --
> 2.36.0.464.gb9c8b46e94-goog
>