perf evlist: Refactor evlist__for_each_cpu()

Previously evlist__for_each_cpu() needed to iterate over the evlist in
an inner loop and call "skip" routines. Refactor this so that the
iteratr is smarter and the next function can update both the current CPU
and evsel.

By using a cpu map index, fix apparent off-by-1 in __run_perf_stat's
call to perf_evsel__close_cpu().

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Vineet Singh <vineet.singh@intel.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: zhengjun.xing@intel.com
Link: https://lore.kernel.org/r/20220105061351.120843-35-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 86 insertions, 93 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a518fcf0b3f8..f84116c9e016 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -405,36 +405,33 @@ static int read_counter_cpu(struct evsel *counter, struct timespec *rs, int cpu)
 
 static int read_affinity_counters(struct timespec *rs)
 {
-	struct evsel *counter;
-	struct affinity affinity;
-	int i, ncpus, cpu;
+	struct evlist_cpu_iterator evlist_cpu_itr;
+	struct affinity saved_affinity, *affinity;
 
 	if (all_counters_use_bpf)
 		return 0;
 
-	if (affinity__setup(&affinity) < 0)
+	if (!target__has_cpu(&target) || target__has_per_thread(&target))
+		affinity = NULL;
+	else if (affinity__setup(&saved_affinity) < 0)
 		return -1;
+	else
+		affinity = &saved_affinity;
 
-	ncpus = perf_cpu_map__nr(evsel_list->core.all_cpus);
-	if (!target__has_cpu(&target) || target__has_per_thread(&target))
-		ncpus = 1;
-	evlist__for_each_cpu(evsel_list, i, cpu) {
-		if (i >= ncpus)
-			break;
-		affinity__set(&affinity, cpu);
+	evlist__for_each_cpu(evlist_cpu_itr, evsel_list, affinity) {
+		struct evsel *counter = evlist_cpu_itr.evsel;
 
-		evlist__for_each_entry(evsel_list, counter) {
-			if (evsel__cpu_iter_skip(counter, cpu))
-				continue;
-			if (evsel__is_bpf(counter))
-				continue;
-			if (!counter->err) {
-				counter->err = read_counter_cpu(counter, rs,
-								counter->cpu_iter - 1);
-			}
+		if (evsel__is_bpf(counter))
+			continue;
+
+		if (!counter->err) {
+			counter->err = read_counter_cpu(counter, rs,
+							evlist_cpu_itr.cpu_map_idx);
 		}
 	}
-	affinity__cleanup(&affinity);
+	if (affinity)
+		affinity__cleanup(&saved_affinity);
+
 	return 0;
 }
 
@@ -788,8 +785,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	int status = 0;
 	const bool forks = (argc > 0);
 	bool is_pipe = STAT_RECORD ? perf_stat.data.is_pipe : false;
+	struct evlist_cpu_iterator evlist_cpu_itr;
 	struct affinity affinity;
-	int i, cpu, err;
+	int err;
 	bool second_pass = false;
 
 	if (forks) {
@@ -813,102 +811,97 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			all_counters_use_bpf = false;
 	}
 
-	evlist__for_each_cpu (evsel_list, i, cpu) {
+	evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) {
+		counter = evlist_cpu_itr.evsel;
+
 		/*
 		 * bperf calls evsel__open_per_cpu() in bperf__load(), so
 		 * no need to call it again here.
 		 */
 		if (target.use_bpf)
 			break;
-		affinity__set(&affinity, cpu);
 
-		evlist__for_each_entry(evsel_list, counter) {
-			if (evsel__cpu_iter_skip(counter, cpu))
+		if (counter->reset_group || counter->errored)
+			continue;
+		if (evsel__is_bpf(counter))
+			continue;
+try_again:
+		if (create_perf_stat_counter(counter, &stat_config, &target,
+					     evlist_cpu_itr.cpu_map_idx) < 0) {
+
+			/*
+			 * Weak group failed. We cannot just undo this here
+			 * because earlier CPUs might be in group mode, and the kernel
+			 * doesn't support mixing group and non group reads. Defer
+			 * it to later.
+			 * Don't close here because we're in the wrong affinity.
+			 */
+			if ((errno == EINVAL || errno == EBADF) &&
+				evsel__leader(counter) != counter &&
+				counter->weak_group) {
+				evlist__reset_weak_group(evsel_list, counter, false);
+				assert(counter->reset_group);
+				second_pass = true;
 				continue;
-			if (counter->reset_group || counter->errored)
+			}
+
+			switch (stat_handle_error(counter)) {
+			case COUNTER_FATAL:
+				return -1;
+			case COUNTER_RETRY:
+				goto try_again;
+			case COUNTER_SKIP:
 				continue;
-			if (evsel__is_bpf(counter))
+			default:
+				break;
+			}
+
+		}
+		counter->supported = true;
+	}
+
+	if (second_pass) {
+		/*
+		 * Now redo all the weak group after closing them,
+		 * and also close errored counters.
+		 */
+
+		/* First close errored or weak retry */
+		evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) {
+			counter = evlist_cpu_itr.evsel;
+
+			if (!counter->reset_group && !counter->errored)
 				continue;
-try_again:
+
+			perf_evsel__close_cpu(&counter->core, evlist_cpu_itr.cpu_map_idx);
+		}
+		/* Now reopen weak */
+		evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) {
+			counter = evlist_cpu_itr.evsel;
+
+			if (!counter->reset_group && !counter->errored)
+				continue;
+			if (!counter->reset_group)
+				continue;
+try_again_reset:
+			pr_debug2("reopening weak %s\n", evsel__name(counter));
 			if (create_perf_stat_counter(counter, &stat_config, &target,
-						     counter->cpu_iter - 1) < 0) {
-
-				/*
-				 * Weak group failed. We cannot just undo this here
-				 * because earlier CPUs might be in group mode, and the kernel
-				 * doesn't support mixing group and non group reads. Defer
-				 * it to later.
-				 * Don't close here because we're in the wrong affinity.
-				 */
-				if ((errno == EINVAL || errno == EBADF) &&
-				    evsel__leader(counter) != counter &&
-				    counter->weak_group) {
-					evlist__reset_weak_group(evsel_list, counter, false);
-					assert(counter->reset_group);
-					second_pass = true;
-					continue;
-				}
+						     evlist_cpu_itr.cpu_map_idx) < 0) {
 
 				switch (stat_handle_error(counter)) {
 				case COUNTER_FATAL:
 					return -1;
 				case COUNTER_RETRY:
-					goto try_again;
+					goto try_again_reset;
 				case COUNTER_SKIP:
 					continue;
 				default:
 					break;
 				}
-
 			}
 			counter->supported = true;
 		}
 	}
-
-	if (second_pass) {
-		/*
-		 * Now redo all the weak group after closing them,
-		 * and also close errored counters.
-		 */
-
-		evlist__for_each_cpu(evsel_list, i, cpu) {
-			affinity__set(&affinity, cpu);
-			/* First close errored or weak retry */
-			evlist__for_each_entry(evsel_list, counter) {
-				if (!counter->reset_group && !counter->errored)
-					continue;
-				if (evsel__cpu_iter_skip_no_inc(counter, cpu))
-					continue;
-				perf_evsel__close_cpu(&counter->core, counter->cpu_iter);
-			}
-			/* Now reopen weak */
-			evlist__for_each_entry(evsel_list, counter) {
-				if (!counter->reset_group && !counter->errored)
-					continue;
-				if (evsel__cpu_iter_skip(counter, cpu))
-					continue;
-				if (!counter->reset_group)
-					continue;
-try_again_reset:
-				pr_debug2("reopening weak %s\n", evsel__name(counter));
-				if (create_perf_stat_counter(counter, &stat_config, &target,
-							     counter->cpu_iter - 1) < 0) {
-
-					switch (stat_handle_error(counter)) {
-					case COUNTER_FATAL:
-						return -1;
-					case COUNTER_RETRY:
-						goto try_again_reset;
-					case COUNTER_SKIP:
-						continue;
-					default:
-						break;
-					}
-				}
-				counter->supported = true;
-			}
-		}
-	}
 	affinity__cleanup(&affinity);
 
 	evlist__for_each_entry(evsel_list, counter) {