[v3,26/48] perf evsel: Derive CPUs and threads in alloc_counts

Commit Message

Ian Rogers Dec. 30, 2021, 7:20 a.m. UTC

Passing the number of CPUs and threads allows for an evsel's counts to
be mismatched to its cpu map. To avoid this always derive the counts
size from the cpu map. Change openat-syscall-all-cpus to set the cpus
to allow for this to work.

Signed-off-by: Ian Rogers <[e-mail]>
---
 tools/perf/tests/openat-syscall-all-cpus.c | 10 +---------
 tools/perf/util/counts.c                   |  8 ++++++--
 tools/perf/util/counts.h                   |  2 +-
 tools/perf/util/evsel.c                    |  2 +-
 tools/perf/util/stat.c                     | 13 ++++++-------
 5 files changed, 15 insertions(+), 20 deletions(-)

Patch

diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
index cd3dd463783f..544db0839b3b 100644
--- a/tools/perf/tests/openat-syscall-all-cpus.c
+++ b/tools/perf/tests/openat-syscall-all-cpus.c
@@ -85,15 +85,7 @@  static int test__openat_syscall_event_on_all_cpus(struct test_suite *test __mayb
 		CPU_CLR(cpus->map[cpu], &cpu_set);
 	}
 
-	/*
-	 * Here we need to explicitly preallocate the counts, as if
-	 * we use the auto allocation it will allocate just for 1 cpu,
-	 * as we start by cpu 0.
-	 */
-	if (evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
-		pr_debug("evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
-		goto out_close_fd;
-	}
+	evsel->core.cpus = perf_cpu_map__get(cpus);
 
 	err = 0;
 
diff --git a/tools/perf/util/counts.c b/tools/perf/util/counts.c
index 582f3aeaf5e4..2b81707b9dba 100644
--- a/tools/perf/util/counts.c
+++ b/tools/perf/util/counts.c
@@ -4,6 +4,7 @@ 
 #include <string.h>
 #include "evsel.h"
 #include "counts.h"
+#include <perf/threadmap.h>
 #include <linux/zalloc.h>
 
 struct perf_counts *perf_counts__new(int ncpus, int nthreads)
@@ -55,9 +56,12 @@  void evsel__reset_counts(struct evsel *evsel)
 	perf_counts__reset(evsel->counts);
 }
 
-int evsel__alloc_counts(struct evsel *evsel, int ncpus, int nthreads)
+int evsel__alloc_counts(struct evsel *evsel)
 {
-	evsel->counts = perf_counts__new(ncpus, nthreads);
+	struct perf_cpu_map *cpus = evsel__cpus(evsel);
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
+
+	evsel->counts = perf_counts__new(cpus ? cpus->nr : 1, nthreads);
 	return evsel->counts != NULL ? 0 : -ENOMEM;
 }
 
diff --git a/tools/perf/util/counts.h b/tools/perf/util/counts.h
index 7ff36bf6d644..3e275e9c60d1 100644
--- a/tools/perf/util/counts.h
+++ b/tools/perf/util/counts.h
@@ -40,7 +40,7 @@  void perf_counts__delete(struct perf_counts *counts);
 void perf_counts__reset(struct perf_counts *counts);
 
 void evsel__reset_counts(struct evsel *evsel);
-int evsel__alloc_counts(struct evsel *evsel, int ncpus, int nthreads);
+int evsel__alloc_counts(struct evsel *evsel);
 void evsel__free_counts(struct evsel *evsel);
 
 #endif /* __PERF_COUNTS_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 656c30b988ce..6c9af21776e6 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1578,7 +1578,7 @@  int __evsel__read_on_cpu(struct evsel *evsel, int cpu, int thread, bool scale)
 	if (FD(evsel, cpu, thread) < 0)
 		return -EINVAL;
 
-	if (evsel->counts == NULL && evsel__alloc_counts(evsel, cpu + 1, thread + 1) < 0)
+	if (evsel->counts == NULL && evsel__alloc_counts(evsel) < 0)
 		return -ENOMEM;
 
 	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) <= 0)
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index c69b221f5e3e..995cb5003133 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -152,11 +152,13 @@  static void evsel__free_stat_priv(struct evsel *evsel)
 	zfree(&evsel->stats);
 }
 
-static int evsel__alloc_prev_raw_counts(struct evsel *evsel, int ncpus, int nthreads)
+static int evsel__alloc_prev_raw_counts(struct evsel *evsel)
 {
+	int cpu_map_nr = evsel__nr_cpus(evsel);
+	int nthreads = perf_thread_map__nr(evsel->core.threads);
 	struct perf_counts *counts;
 
-	counts = perf_counts__new(ncpus, nthreads);
+	counts = perf_counts__new(cpu_map_nr, nthreads);
 	if (counts)
 		evsel->prev_raw_counts = counts;
 
@@ -177,12 +179,9 @@  static void evsel__reset_prev_raw_counts(struct evsel *evsel)
 
 static int evsel__alloc_stats(struct evsel *evsel, bool alloc_raw)
 {
-	int ncpus = evsel__nr_cpus(evsel);
-	int nthreads = perf_thread_map__nr(evsel->core.threads);
-
 	if (evsel__alloc_stat_priv(evsel) < 0 ||
-	    evsel__alloc_counts(evsel, ncpus, nthreads) < 0 ||
-	    (alloc_raw && evsel__alloc_prev_raw_counts(evsel, ncpus, nthreads) < 0))
+	    evsel__alloc_counts(evsel) < 0 ||
+	    (alloc_raw && evsel__alloc_prev_raw_counts(evsel) < 0))
 		return -ENOMEM;
 
 	return 0;