Re: [PATCH v4 48/48] perf cpumap: Give CPUs their own type.

[Arnaldo Carvalho de Melo <acme@kernel.org>]

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.

- 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);