[PATCH v3 4/4] perf-stat: introduce ':b' modifier

Song Liu
2021-04-16T22:13:56Z

Introduce 'b' modifier to event parser, which means use BPF program to
manage this event. This is the same as --bpf-counters option, but only
applies to this event. For example,

perf stat -e cycles:b,cs # use bpf for cycles, but not cs
perf stat -e cycles,cs --bpf-counters # use bpf for both cycles and cs

Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
---
tools/perf/util/bpf_counter.c | 2 +-
tools/perf/util/evsel.h | 1 +
tools/perf/util/parse-events.c | 8 +++++++-
tools/perf/util/parse-events.l | 2 +-
4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index 3189b63714371..7b4d511c7e6ec 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -790,7 +790,7 @@ 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->bpf_counter)
evsel->bpf_counter_ops = &bperf_ops;
else if (evsel__match_bpf_counter_events(evsel->name))
evsel->bpf_counter_ops = &bperf_ops;
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index ce4b629d659c2..8f66cdcb338d0 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -82,6 +82,7 @@ struct evsel {
bool auto_merge_stats;
bool collect_stat;
bool weak_group;
+ bool bpf_counter;
int bpf_fd;
struct bpf_object *bpf_obj;
};
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 8123d218ad17c..46ebd269a98d1 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1804,6 +1804,7 @@ struct event_modifier {
int pinned;
int weak;
int exclusive;
+ int bpf_counter;
};

static int get_event_modifier(struct event_modifier *mod, char *str,
@@ -1824,6 +1825,7 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
int exclude = eu | ek | eh;
int exclude_GH = evsel ? evsel->exclude_GH : 0;
int weak = 0;
+ int bpf_counter = 0;

memset(mod, 0, sizeof(*mod));

@@ -1867,6 +1869,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
exclusive = 1;
} else if (*str == 'W') {
weak = 1;
+ } else if (*str == 'b') {
+ bpf_counter = 1;
} else
break;

@@ -1898,6 +1902,7 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
mod->sample_read = sample_read;
mod->pinned = pinned;
mod->weak = weak;
+ mod->bpf_counter = bpf_counter;
mod->exclusive = exclusive;

return 0;
@@ -1912,7 +1917,7 @@ static int check_modifier(char *str)
char *p = str;

/* The sizeof includes 0 byte as well. */
- if (strlen(str) > (sizeof("ukhGHpppPSDIWe") - 1))
+ if (strlen(str) > (sizeof("ukhGHpppPSDIWeb") - 1))
return -1;

while (*p) {
@@ -1953,6 +1958,7 @@ int parse_events__modifier_event(struct list_head *list, char *str, bool add)
evsel->sample_read = mod.sample_read;
evsel->precise_max = mod.precise_max;
evsel->weak_group = mod.weak;
+ evsel->bpf_counter = mod.bpf_counter;

if (evsel__is_group_leader(evsel)) {
evsel->core.attr.pinned = mod.pinned;
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 0b36285a9435d..fb8646cc3e834 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -210,7 +210,7 @@ name_tag [\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
name_minus [a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?
/* If you add a modifier you need to update check_modifier() */
-modifier_event [ukhpPGHSDIWe]+
+modifier_event [ukhpPGHSDIWeb]+
modifier_bp [rwx]{1,3}

%%
--
2.30.2