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. This is limited to hardware events in
evsel__hw_names.
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 <[email protected]>
---
tools/perf/Documentation/perf-stat.txt | 2 ++
tools/perf/builtin-stat.c | 41 ++++++++++++++++----------
tools/perf/util/bpf_counter.c | 11 +++++++
tools/perf/util/config.c | 32 ++++++++++++++++++++
tools/perf/util/evsel.c | 2 ++
tools/perf/util/evsel.h | 1 +
tools/perf/util/target.h | 5 ----
7 files changed, 74 insertions(+), 20 deletions(-)
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 744211fa8c186..6d4733eaac170 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -97,6 +97,8 @@ report::
Use BPF programs to aggregate readings from perf_events. This
allows multiple perf-stat sessions that are counting the same metric (cycles,
instructions, etc.) to share hardware counters.
+ To use BPF programs on common hardware events by default, use
+ "perf config stat.bpf-counter-events=<list_of_events>".
--bpf-attr-map::
With option "--bpf-counters", different perf-stat sessions share
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 4bb48c6b66980..5adfa708ffe68 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -423,17 +423,28 @@ static int read_affinity_counters(struct timespec *rs)
return 0;
}
+/*
+ * Returns:
+ * 0 if all events use BPF;
+ * 1 if some events do NOT use BPF;
+ * < 0 on errors;
+ */
static int read_bpf_map_counters(void)
{
+ bool has_none_bpf_events = false;
struct evsel *counter;
int err;
evlist__for_each_entry(evsel_list, counter) {
+ if (!counter->bpf_counter_ops) {
+ has_none_bpf_events = true;
+ continue;
+ }
err = bpf_counter__read(counter);
if (err)
return err;
}
- return 0;
+ return has_none_bpf_events ? 1 : 0;
}
static void read_counters(struct timespec *rs)
@@ -442,9 +453,10 @@ static void read_counters(struct timespec *rs)
int err;
if (!stat_config.stop_read_counter) {
- if (target__has_bpf(&target))
- err = read_bpf_map_counters();
- else
+ err = read_bpf_map_counters();
+ if (err < 0)
+ return;
+ if (err)
err = read_affinity_counters(rs);
if (err < 0)
return;
@@ -535,12 +547,13 @@ static int enable_counters(void)
struct evsel *evsel;
int err;
- if (target__has_bpf(&target)) {
- evlist__for_each_entry(evsel_list, evsel) {
- err = bpf_counter__enable(evsel);
- if (err)
- return err;
- }
+ evlist__for_each_entry(evsel_list, evsel) {
+ if (!evsel->bpf_counter_ops)
+ continue;
+
+ err = bpf_counter__enable(evsel);
+ if (err)
+ return err;
}
if (stat_config.initial_delay < 0) {
@@ -784,11 +797,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (affinity__setup(&affinity) < 0)
return -1;
- if (target__has_bpf(&target)) {
- evlist__for_each_entry(evsel_list, counter) {
- if (bpf_counter__load(counter, &target))
- return -1;
- }
+ evlist__for_each_entry(evsel_list, counter) {
+ if (bpf_counter__load(counter, &target))
+ return -1;
}
evlist__for_each_cpu (evsel_list, i, cpu) {
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index df70c8dcf7850..ea45914af1693 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -792,6 +792,17 @@ int bpf_counter__load(struct evsel *evsel, struct target *target)
evsel->bpf_counter_ops = &bpf_program_profiler_ops;
else if (target->use_bpf)
evsel->bpf_counter_ops = &bperf_ops;
+ else {
+ int i;
+
+ for (i = 0; i < PERF_COUNT_HW_MAX; i++) {
+ if (!strcmp(evsel->name, evsel__hw_names[i])) {
+ if (evsel__use_bpf_counters[i])
+ evsel->bpf_counter_ops = &bperf_ops;
+ break;
+ }
+ }
+ }
if (evsel->bpf_counter_ops)
return evsel->bpf_counter_ops->load(evsel, target);
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 2daeaa9a4a241..fe2ec56258735 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"
@@ -433,6 +434,29 @@ static int perf_buildid_config(const char *var, const char *value)
return 0;
}
+static int perf_stat_config_parse_bpf_counter_event(const char *value)
+{
+ char *event_str, *event_str_, *tok, *saveptr = NULL;
+ int i;
+
+ event_str_ = event_str = strdup(value);
+ if (!event_str)
+ return -1;
+
+ while ((tok = strtok_r(event_str, ",", &saveptr)) != NULL) {
+ for (i = 0; i < PERF_COUNT_HW_MAX; i++) {
+ if (!strcmp(tok, evsel__hw_names[i])) {
+ evsel__use_bpf_counters[i] = true;
+ break;
+ }
+ }
+ event_str = NULL;
+ }
+
+ free(event_str_);
+ return 0;
+}
+
static int perf_default_core_config(const char *var __maybe_unused,
const char *value __maybe_unused)
{
@@ -454,9 +478,17 @@ static int perf_ui_config(const char *var, const char *value)
static int perf_stat_config(const char *var, const char *value)
{
+ int err = 0;
+
if (!strcmp(var, "stat.big-num"))
perf_stat__set_big_num(perf_config_bool(var, value));
+ if (!strcmp(var, "stat.bpf-counter-events")) {
+ err = perf_stat_config_parse_bpf_counter_event(value);
+ if (err)
+ return err;
+ }
+
/* Add other config variables here. */
return 0;
}
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 2d2614eeaa20e..592d93bcccd04 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -492,6 +492,8 @@ const char *evsel__hw_names[PERF_COUNT_HW_MAX] = {
"ref-cycles",
};
+bool evsel__use_bpf_counters[PERF_COUNT_HW_MAX] = {false};
+
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 dd4f56f9cfdf5..32439c5684f7d 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -247,6 +247,7 @@ 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 bool evsel__use_bpf_counters[PERF_COUNT_HW_MAX];
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 1bce3eb28ef25..4ff56217f2a65 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);
--
2.30.2
On Fri, Apr 02, 2021 at 05:29:38PM -0700, Song Liu wrote:
> 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. This is limited to hardware events in
> evsel__hw_names.
>
> 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
hum, so this will effectively allow to mix 'bpf-shared' counters
with normals ones.. I don't think we're ready for that ;-)
>
> The second command will use BPF for "instructions" but not "cs".
>
> Signed-off-by: Song Liu <[email protected]>
> ---
> tools/perf/Documentation/perf-stat.txt | 2 ++
> tools/perf/builtin-stat.c | 41 ++++++++++++++++----------
> tools/perf/util/bpf_counter.c | 11 +++++++
> tools/perf/util/config.c | 32 ++++++++++++++++++++
> tools/perf/util/evsel.c | 2 ++
> tools/perf/util/evsel.h | 1 +
> tools/perf/util/target.h | 5 ----
> 7 files changed, 74 insertions(+), 20 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
> index 744211fa8c186..6d4733eaac170 100644
> --- a/tools/perf/Documentation/perf-stat.txt
> +++ b/tools/perf/Documentation/perf-stat.txt
> @@ -97,6 +97,8 @@ report::
> Use BPF programs to aggregate readings from perf_events. This
> allows multiple perf-stat sessions that are counting the same metric (cycles,
> instructions, etc.) to share hardware counters.
> + To use BPF programs on common hardware events by default, use
> + "perf config stat.bpf-counter-events=<list_of_events>".
>
> --bpf-attr-map::
> With option "--bpf-counters", different perf-stat sessions share
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 4bb48c6b66980..5adfa708ffe68 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -423,17 +423,28 @@ static int read_affinity_counters(struct timespec *rs)
> return 0;
> }
>
> +/*
> + * Returns:
> + * 0 if all events use BPF;
> + * 1 if some events do NOT use BPF;
> + * < 0 on errors;
> + */
> static int read_bpf_map_counters(void)
> {
> + bool has_none_bpf_events = false;
> struct evsel *counter;
> int err;
>
> evlist__for_each_entry(evsel_list, counter) {
> + if (!counter->bpf_counter_ops) {
> + has_none_bpf_events = true;
> + continue;
> + }
> err = bpf_counter__read(counter);
> if (err)
> return err;
> }
> - return 0;
> + return has_none_bpf_events ? 1 : 0;
> }
>
> static void read_counters(struct timespec *rs)
> @@ -442,9 +453,10 @@ static void read_counters(struct timespec *rs)
> int err;
>
> if (!stat_config.stop_read_counter) {
> - if (target__has_bpf(&target))
> - err = read_bpf_map_counters();
> - else
> + err = read_bpf_map_counters();
> + if (err < 0)
> + return;
> + if (err)
> err = read_affinity_counters(rs);
so read_affinity_counters will read also 'bpf-shared' counters no?
as long as it was separated, I did not see a problem, now we have
counters that either have bpf ops set or have not
it'd be great to do some generic separation.. I was thinking to move
bpf_counter_ops into some generic counter ops and we would just fill
in the proper ops for the counter.. buuut the affinity readings are
not compatible with what we are doing in bperf_read and the profiler
bpf read
so I think the solution will be just to skip those events in
read_affinity_counters and all the other code, and have some
helper like:
bool evsel__is_bpf(evsel)
so it's clear why it's skipped
thanks,
jirka
> On Apr 6, 2021, at 7:21 AM, Jiri Olsa <[email protected]> wrote:
>
> On Fri, Apr 02, 2021 at 05:29:38PM -0700, Song Liu wrote:
>> 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. This is limited to hardware events in
>> evsel__hw_names.
>>
>> 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
>
> hum, so this will effectively allow to mix 'bpf-shared' counters
> with normals ones.. I don't think we're ready for that ;-)
I think we are ready. :) all bpf_counter stuff is within evsel, so mixing
them doesn't need much work.
>
>>
>> The second command will use BPF for "instructions" but not "cs".
>>
>> Signed-off-by: Song Liu <[email protected]>
>> ---
>> tools/perf/Documentation/perf-stat.txt | 2 ++
>> tools/perf/builtin-stat.c | 41 ++++++++++++++++----------
>> tools/perf/util/bpf_counter.c | 11 +++++++
>> tools/perf/util/config.c | 32 ++++++++++++++++++++
>> tools/perf/util/evsel.c | 2 ++
>> tools/perf/util/evsel.h | 1 +
>> tools/perf/util/target.h | 5 ----
>> 7 files changed, 74 insertions(+), 20 deletions(-)
>>
>> diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
>> index 744211fa8c186..6d4733eaac170 100644
>> --- a/tools/perf/Documentation/perf-stat.txt
>> +++ b/tools/perf/Documentation/perf-stat.txt
>> @@ -97,6 +97,8 @@ report::
>> Use BPF programs to aggregate readings from perf_events. This
>> allows multiple perf-stat sessions that are counting the same metric (cycles,
>> instructions, etc.) to share hardware counters.
>> + To use BPF programs on common hardware events by default, use
>> + "perf config stat.bpf-counter-events=<list_of_events>".
>>
>> --bpf-attr-map::
>> With option "--bpf-counters", different perf-stat sessions share
>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>> index 4bb48c6b66980..5adfa708ffe68 100644
>> --- a/tools/perf/builtin-stat.c
>> +++ b/tools/perf/builtin-stat.c
>> @@ -423,17 +423,28 @@ static int read_affinity_counters(struct timespec *rs)
>> return 0;
>> }
>>
>> +/*
>> + * Returns:
>> + * 0 if all events use BPF;
>> + * 1 if some events do NOT use BPF;
>> + * < 0 on errors;
>> + */
>> static int read_bpf_map_counters(void)
>> {
>> + bool has_none_bpf_events = false;
>> struct evsel *counter;
>> int err;
>>
>> evlist__for_each_entry(evsel_list, counter) {
>> + if (!counter->bpf_counter_ops) {
>> + has_none_bpf_events = true;
>> + continue;
>> + }
>> err = bpf_counter__read(counter);
>> if (err)
>> return err;
>> }
>> - return 0;
>> + return has_none_bpf_events ? 1 : 0;
>> }
>>
>> static void read_counters(struct timespec *rs)
>> @@ -442,9 +453,10 @@ static void read_counters(struct timespec *rs)
>> int err;
>>
>> if (!stat_config.stop_read_counter) {
>> - if (target__has_bpf(&target))
>> - err = read_bpf_map_counters();
>> - else
>> + err = read_bpf_map_counters();
>> + if (err < 0)
>> + return;
>> + if (err)
>> err = read_affinity_counters(rs);
>
> so read_affinity_counters will read also 'bpf-shared' counters no?
> as long as it was separated, I did not see a problem, now we have
> counters that either have bpf ops set or have not
>
> it'd be great to do some generic separation.. I was thinking to move
> bpf_counter_ops into some generic counter ops and we would just fill
> in the proper ops for the counter.. buuut the affinity readings are
> not compatible with what we are doing in bperf_read and the profiler
> bpf read
>
> so I think the solution will be just to skip those events in
> read_affinity_counters and all the other code, and have some
> helper like:
>
> bool evsel__is_bpf(evsel)
>
> so it's clear why it's skipped
Yes, this will be better! Current version does have the problem of
extra read in read_affinity_counters(). Will fix this.
Thanks,
Song