Re: [PATCH v4 48/48] perf cpumap: Give CPUs their own type.
From: Ian Rogers
Date: Tue Jan 11 2022 - 14:17:23 EST
On Mon, Jan 10, 2022 at 11:50 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Tue, Jan 04, 2022 at 10:13:51PM -0800, Ian Rogers escreveu:
> > A common problem is confusing CPU map indices with the CPU, by wrapping
> > the CPU with a struct then this is avoided. This approach is similar to
> > atomic_t.
>
> This one needed this to build with BUILD_BPF_SKEL=1, please check, I'll
> soon push this to tmp.perf/perf_cpu so that you can take a look and test
> it.
Thanks Arnaldo, I did eye-ball one issue where cpu_map__default_new's
behavior would be impacted (nr would be 1 rather than nr_cpus). The
fix is:
--- a/tools/lib/perf/cpumap.c
+++ b/tools/lib/perf/cpumap.c
@@ -18,7 +18,7 @@ static struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
if (!cpus)
return NULL;
- cpus->nr = 1;
+ cpus->nr = nr_cpus;
refcount_set(&cpus->refcnt, 1);
return cpus;
}
Could you add that into this patch as well?
Thanks,
Ian
> - Arnaldo
>
> diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
> index 80d1a3a31052fe55..328479df5e16a638 100644
> --- a/tools/perf/util/bpf_counter.c
> +++ b/tools/perf/util/bpf_counter.c
> @@ -540,7 +540,7 @@ static int bperf__load(struct evsel *evsel, struct target *target)
> filter_type == BPERF_FILTER_TGID)
> key = evsel->core.threads->map[i].pid;
> else if (filter_type == BPERF_FILTER_CPU)
> - key = evsel->core.cpus->map[i];
> + key = evsel->core.cpus->map[i].cpu;
> else
> break;
>
> @@ -584,7 +584,7 @@ static int bperf_sync_counters(struct evsel *evsel)
>
> num_cpu = all_cpu_map->nr;
> for (i = 0; i < num_cpu; i++) {
> - cpu = all_cpu_map->map[i];
> + cpu = all_cpu_map->map[i].cpu;
> bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu);
> }
> return 0;
> @@ -605,7 +605,7 @@ static int bperf__disable(struct evsel *evsel)
> static int bperf__read(struct evsel *evsel)
> {
> struct bperf_follower_bpf *skel = evsel->follower_skel;
> - __u32 num_cpu_bpf = cpu__max_cpu();
> + __u32 num_cpu_bpf = cpu__max_cpu().cpu;
> struct bpf_perf_event_value values[num_cpu_bpf];
> int reading_map_fd, err = 0;
> __u32 i;
> @@ -615,6 +615,7 @@ static int bperf__read(struct evsel *evsel)
> reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
>
> for (i = 0; i < bpf_map__max_entries(skel->maps.accum_readings); i++) {
> + struct perf_cpu entry;
> __u32 cpu;
>
> err = bpf_map_lookup_elem(reading_map_fd, &i, values);
> @@ -624,14 +625,15 @@ static int bperf__read(struct evsel *evsel)
> case BPERF_FILTER_GLOBAL:
> assert(i == 0);
>
> - perf_cpu_map__for_each_cpu(cpu, j, all_cpu_map) {
> + perf_cpu_map__for_each_cpu(entry, j, all_cpu_map) {
> + cpu = entry.cpu;
> perf_counts(evsel->counts, cpu, 0)->val = values[cpu].counter;
> perf_counts(evsel->counts, cpu, 0)->ena = values[cpu].enabled;
> perf_counts(evsel->counts, cpu, 0)->run = values[cpu].running;
> }
> break;
> case BPERF_FILTER_CPU:
> - cpu = evsel->core.cpus->map[i];
> + cpu = evsel->core.cpus->map[i].cpu;
> perf_counts(evsel->counts, i, 0)->val = values[cpu].counter;
> perf_counts(evsel->counts, i, 0)->ena = values[cpu].enabled;
> perf_counts(evsel->counts, i, 0)->run = values[cpu].running;
> diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
> index cbc6c2bca488f6bf..631e34a0b66ff084 100644
> --- a/tools/perf/util/bpf_counter_cgroup.c
> +++ b/tools/perf/util/bpf_counter_cgroup.c
> @@ -48,7 +48,7 @@ static int bperf_load_program(struct evlist *evlist)
> struct cgroup *cgrp, *leader_cgrp;
> __u32 i, cpu;
> __u32 nr_cpus = evlist->core.all_cpus->nr;
> - int total_cpus = cpu__max_cpu();
> + int total_cpus = cpu__max_cpu().cpu;
> int map_size, map_fd;
> int prog_fd, err;
>
> @@ -125,7 +125,7 @@ static int bperf_load_program(struct evlist *evlist)
> 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];
> + evlist->core.all_cpus->map[cpu].cpu;
>
> err = bpf_map_update_elem(map_fd, &idx, &fd,
> BPF_ANY);
> @@ -212,7 +212,7 @@ static int bperf_cgrp__sync_counters(struct evlist *evlist)
> 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 = evlist->core.all_cpus->map[i].cpu;
> bperf_trigger_reading(prog_fd, cpu);
> }
>
> @@ -245,7 +245,7 @@ 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();
> + int total_cpus = cpu__max_cpu().cpu;
> struct perf_counts_values *counts;
> struct bpf_perf_event_value *values;
> int reading_map_fd, err = 0;
> @@ -272,7 +272,7 @@ static int bperf_cgrp__read(struct evsel *evsel)
> }
>
> for (i = 0; i < nr_cpus; i++) {
> - cpu = evlist->core.all_cpus->map[i];
> + cpu = evlist->core.all_cpus->map[i].cpu;
>
> counts = perf_counts(evsel->counts, i, 0);
> counts->val = values[cpu].counter;
> diff --git a/tools/perf/util/bpf_ftrace.c b/tools/perf/util/bpf_ftrace.c
> index 28dc4c60c7884818..d756cc66eef32ae8 100644
> --- a/tools/perf/util/bpf_ftrace.c
> +++ b/tools/perf/util/bpf_ftrace.c
> @@ -63,7 +63,7 @@ int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
> fd = bpf_map__fd(skel->maps.cpu_filter);
>
> for (i = 0; i < ncpus; i++) {
> - cpu = perf_cpu_map__cpu(ftrace->evlist->core.cpus, i);
> + cpu = perf_cpu_map__cpu(ftrace->evlist->core.cpus, i).cpu;
> bpf_map_update_elem(fd, &cpu, &val, BPF_ANY);
> }
> }
> @@ -122,7 +122,7 @@ int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused,
> int i, fd, err;
> u32 idx;
> u64 *hist;
> - int ncpus = cpu__max_cpu();
> + int ncpus = cpu__max_cpu().cpu;
>
> fd = bpf_map__fd(skel->maps.latency);
>