perf stat: Introduce config stat.bpf-counter-events

Currently, to use BPF to aggregate perf event counters, the user uses
--bpf-counters option. Enable "use bpf by default" events with a config
option, stat.bpf-counter-events. Events with name in the option will use
BPF.

This also enables mixed BPF event and regular event in the same sesssion.
For example:

   perf config stat.bpf-counter-events=instructions
   perf stat -e instructions,cs

The second command will use BPF for "instructions" but not "cs".

Signed-off-by: Song Liu <song@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/r/20210425214333.1090950-4-song@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 36 insertions, 6 deletions

diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index 5de991ab46af..33b1888103df 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -790,7 +790,8 @@ int bpf_counter__load(struct evsel *evsel, struct target *target)
 {
 	if (target->bpf_str)
 		evsel->bpf_counter_ops = &bpf_program_profiler_ops;
-	else if (target->use_bpf)
+	else if (target->use_bpf ||
+		 evsel__match_bpf_counter_events(evsel->name))
 		evsel->bpf_counter_ops = &bperf_ops;
 
 	if (evsel->bpf_counter_ops)
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 6bcb5ef221f8..63d472b336de 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -18,6 +18,7 @@
 #include "util/hist.h"  /* perf_hist_config */
 #include "util/llvm-utils.h"   /* perf_llvm_config */
 #include "util/stat.h"  /* perf_stat__set_big_num */
+#include "util/evsel.h"  /* evsel__hw_names, evsel__use_bpf_counters */
 #include "build-id.h"
 #include "debug.h"
 #include "config.h"
@@ -460,6 +461,9 @@ static int perf_stat_config(const char *var, const char *value)
 	if (!strcmp(var, "stat.no-csv-summary"))
 		perf_stat__set_no_csv_summary(perf_config_bool(var, value));
 
+	if (!strcmp(var, "stat.bpf-counter-events"))
+		evsel__bpf_counter_events = strdup(value);
+
 	/* Add other config variables here. */
 	return 0;
 }
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2d2614eeaa20..080ddcfefbcd 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -492,6 +492,28 @@ const char *evsel__hw_names[PERF_COUNT_HW_MAX] = {
 	"ref-cycles",
 };
 
+char *evsel__bpf_counter_events;
+
+bool evsel__match_bpf_counter_events(const char *name)
+{
+	int name_len;
+	bool match;
+	char *ptr;
+
+	if (!evsel__bpf_counter_events)
+		return false;
+
+	ptr = strstr(evsel__bpf_counter_events, name);
+	name_len = strlen(name);
+
+	/* check name matches a full token in evsel__bpf_counter_events */
+	match = (ptr != NULL) &&
+		((ptr == evsel__bpf_counter_events) || (*(ptr - 1) == ',')) &&
+		((*(ptr + name_len) == ',') || (*(ptr + name_len) == '\0'));
+
+	return match;
+}
+
 static const char *__evsel__hw_name(u64 config)
 {
 	if (config < PERF_COUNT_HW_MAX && evsel__hw_names[config])
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index eccc4fd5b3eb..ce4b629d659c 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -239,6 +239,11 @@ void evsel__calc_id_pos(struct evsel *evsel);
 
 bool evsel__is_cache_op_valid(u8 type, u8 op);
 
+static inline bool evsel__is_bpf(struct evsel *evsel)
+{
+	return evsel->bpf_counter_ops != NULL;
+}
+
 #define EVSEL__MAX_ALIASES 8
 
 extern const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX][EVSEL__MAX_ALIASES];
@@ -246,6 +251,9 @@ extern const char *evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX][EVSEL__MAX_ALI
 extern const char *evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX][EVSEL__MAX_ALIASES];
 extern const char *evsel__hw_names[PERF_COUNT_HW_MAX];
 extern const char *evsel__sw_names[PERF_COUNT_SW_MAX];
+extern char *evsel__bpf_counter_events;
+bool evsel__match_bpf_counter_events(const char *name);
+
 int __evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result, char *bf, size_t size);
 const char *evsel__name(struct evsel *evsel);
 
diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h
index 1bce3eb28ef2..4ff56217f2a6 100644
--- a/tools/perf/util/target.h
+++ b/tools/perf/util/target.h
@@ -66,11 +66,6 @@ static inline bool target__has_cpu(struct target *target)
 	return target->system_wide || target->cpu_list;
 }
 
-static inline bool target__has_bpf(struct target *target)
-{
-	return target->bpf_str || target->use_bpf;
-}
-
 static inline bool target__none(struct target *target)
 {
 	return !target__has_task(target) && !target__has_cpu(target);