On hybrid systems, events like msr/tsc/ will aggregate counts across
all CPUs. Often metrics only want a value like msr/tsc/ for the cores
on which the metric is being computed. Listing each CPU with terms
cpu=0,cpu=1.. is laborious and would need to be encoded for all
variations of a CPU model.
Allow the cpumask from a PMU to be an argument to the cpu term. For
example in the following the cpumask of the cstate_pkg PMU selects the
CPUs to count msr/tsc/ counter upon:
```
$ cat /sys/bus/event_source/devices/cstate_pkg/cpumask
0
$ perf stat -A -e 'msr/tsc,cpu=cstate_pkg/' -a sleep 0.1
Performance counter stats for 'system wide':
CPU0 252,621,253 msr/tsc,cpu=cstate_pkg/
0.101184092 seconds time elapsed
```
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/parse-events.c | 37 +++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 9 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 7a32d5234a64..ef38eb082342 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -192,10 +192,20 @@ static struct perf_cpu_map *get_config_cpu(const struct parse_events_terms *head
list_for_each_entry(term, &head_terms->terms, list) {
if (term->type_term == PARSE_EVENTS__TERM_TYPE_CPU) {
- struct perf_cpu_map *cpu = perf_cpu_map__new_int(term->val.num);
+ struct perf_cpu_map *term_cpus;
- perf_cpu_map__merge(&cpus, cpu);
- perf_cpu_map__put(cpu);
+ if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
+ term_cpus = perf_cpu_map__new_int(term->val.num);
+ } else {
+ struct perf_pmu *pmu = perf_pmus__find(term->val.str);
+
+ if (perf_cpu_map__is_empty(pmu->cpus))
+ term_cpus = pmu->is_core ? cpu_map__online() : NULL;
+ else
+ term_cpus = perf_cpu_map__get(pmu->cpus);
+ }
+ perf_cpu_map__merge(&cpus, term_cpus);
+ perf_cpu_map__put(term_cpus);
}
}
@@ -1054,12 +1064,21 @@ do { \
}
break;
case PARSE_EVENTS__TERM_TYPE_CPU:
- CHECK_TYPE_VAL(NUM);
- if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
- parse_events_error__handle(err, term->err_val,
- strdup("too big"),
- NULL);
- return -EINVAL;
+ if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
+ if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
+ parse_events_error__handle(err, term->err_val,
+ strdup("too big"),
+ /*help=*/NULL);
+ return -EINVAL;
+ }
+ } else {
+ assert(term->type_val == PARSE_EVENTS__TERM_TYPE_STR);
+ if (perf_pmus__find(term->val.str) == NULL) {
+ parse_events_error__handle(err, term->err_val,
+ strdup("not a valid PMU"),
+ /*help=*/NULL);
+ return -EINVAL;
+ }
}
break;
case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
--
2.50.0.727.gbf7dc18ff4-googOn Fri, Jun 27, 2025 at 12:24:09PM -0700, Ian Rogers wrote:
> On hybrid systems, events like msr/tsc/ will aggregate counts across
> all CPUs. Often metrics only want a value like msr/tsc/ for the cores
> on which the metric is being computed. Listing each CPU with terms
> cpu=0,cpu=1.. is laborious and would need to be encoded for all
> variations of a CPU model.
>
> Allow the cpumask from a PMU to be an argument to the cpu term. For
> example in the following the cpumask of the cstate_pkg PMU selects the
> CPUs to count msr/tsc/ counter upon:
> ```
> $ cat /sys/bus/event_source/devices/cstate_pkg/cpumask
> 0
> $ perf stat -A -e 'msr/tsc,cpu=cstate_pkg/' -a sleep 0.1
It can be confusing if 'cpu' takes a number or a PMU name. What about
adding a new term (maybe 'cpu_from') to handle this case?
Also please update the documentation.
Thanks,
Namhyung
>
> Performance counter stats for 'system wide':
>
> CPU0 252,621,253 msr/tsc,cpu=cstate_pkg/
>
> 0.101184092 seconds time elapsed
> ```
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/parse-events.c | 37 +++++++++++++++++++++++++---------
> 1 file changed, 28 insertions(+), 9 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 7a32d5234a64..ef38eb082342 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -192,10 +192,20 @@ static struct perf_cpu_map *get_config_cpu(const struct parse_events_terms *head
>
> list_for_each_entry(term, &head_terms->terms, list) {
> if (term->type_term == PARSE_EVENTS__TERM_TYPE_CPU) {
> - struct perf_cpu_map *cpu = perf_cpu_map__new_int(term->val.num);
> + struct perf_cpu_map *term_cpus;
>
> - perf_cpu_map__merge(&cpus, cpu);
> - perf_cpu_map__put(cpu);
> + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
> + term_cpus = perf_cpu_map__new_int(term->val.num);
> + } else {
> + struct perf_pmu *pmu = perf_pmus__find(term->val.str);
> +
> + if (perf_cpu_map__is_empty(pmu->cpus))
> + term_cpus = pmu->is_core ? cpu_map__online() : NULL;
> + else
> + term_cpus = perf_cpu_map__get(pmu->cpus);
> + }
> + perf_cpu_map__merge(&cpus, term_cpus);
> + perf_cpu_map__put(term_cpus);
> }
> }
>
> @@ -1054,12 +1064,21 @@ do { \
> }
> break;
> case PARSE_EVENTS__TERM_TYPE_CPU:
> - CHECK_TYPE_VAL(NUM);
> - if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
> - parse_events_error__handle(err, term->err_val,
> - strdup("too big"),
> - NULL);
> - return -EINVAL;
> + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
> + if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
> + parse_events_error__handle(err, term->err_val,
> + strdup("too big"),
> + /*help=*/NULL);
> + return -EINVAL;
> + }
> + } else {
> + assert(term->type_val == PARSE_EVENTS__TERM_TYPE_STR);
> + if (perf_pmus__find(term->val.str) == NULL) {
> + parse_events_error__handle(err, term->err_val,
> + strdup("not a valid PMU"),
> + /*help=*/NULL);
> + return -EINVAL;
> + }
> }
> break;
> case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
> --
> 2.50.0.727.gbf7dc18ff4-goog
>
On Wed, Jul 16, 2025 at 1:09 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> On Fri, Jun 27, 2025 at 12:24:09PM -0700, Ian Rogers wrote:
> > On hybrid systems, events like msr/tsc/ will aggregate counts across
> > all CPUs. Often metrics only want a value like msr/tsc/ for the cores
> > on which the metric is being computed. Listing each CPU with terms
> > cpu=0,cpu=1.. is laborious and would need to be encoded for all
> > variations of a CPU model.
> >
> > Allow the cpumask from a PMU to be an argument to the cpu term. For
> > example in the following the cpumask of the cstate_pkg PMU selects the
> > CPUs to count msr/tsc/ counter upon:
> > ```
> > $ cat /sys/bus/event_source/devices/cstate_pkg/cpumask
> > 0
> > $ perf stat -A -e 'msr/tsc,cpu=cstate_pkg/' -a sleep 0.1
>
> It can be confusing if 'cpu' takes a number or a PMU name. What about
> adding a new term (maybe 'cpu_from') to handle this case?
So it is possible for terms to be defined in sysfs in the 'format/' folder:
```
$ ls /sys/bus/event_source/devices/cpu_core/format/
cmask edge event frontend inv ldlat offcore_rsp pc umask
```
By not introducing a new term we leave 'cpu_from' open for use in this
way. When I spoke to Kan we thought using the existing term made sense
and fits the idea of leaving things open for the kernel/drivers to
use. It is possible to add a new term though. Let me know and I can
update the patch and documentation accordingly.
Thanks,
Ian
> Also please update the documentation.
>
> Thanks,
> Namhyung
>
> >
> > Performance counter stats for 'system wide':
> >
> > CPU0 252,621,253 msr/tsc,cpu=cstate_pkg/
> >
> > 0.101184092 seconds time elapsed
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> > tools/perf/util/parse-events.c | 37 +++++++++++++++++++++++++---------
> > 1 file changed, 28 insertions(+), 9 deletions(-)
> >
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 7a32d5234a64..ef38eb082342 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -192,10 +192,20 @@ static struct perf_cpu_map *get_config_cpu(const struct parse_events_terms *head
> >
> > list_for_each_entry(term, &head_terms->terms, list) {
> > if (term->type_term == PARSE_EVENTS__TERM_TYPE_CPU) {
> > - struct perf_cpu_map *cpu = perf_cpu_map__new_int(term->val.num);
> > + struct perf_cpu_map *term_cpus;
> >
> > - perf_cpu_map__merge(&cpus, cpu);
> > - perf_cpu_map__put(cpu);
> > + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
> > + term_cpus = perf_cpu_map__new_int(term->val.num);
> > + } else {
> > + struct perf_pmu *pmu = perf_pmus__find(term->val.str);
> > +
> > + if (perf_cpu_map__is_empty(pmu->cpus))
> > + term_cpus = pmu->is_core ? cpu_map__online() : NULL;
> > + else
> > + term_cpus = perf_cpu_map__get(pmu->cpus);
> > + }
> > + perf_cpu_map__merge(&cpus, term_cpus);
> > + perf_cpu_map__put(term_cpus);
> > }
> > }
> >
> > @@ -1054,12 +1064,21 @@ do { \
> > }
> > break;
> > case PARSE_EVENTS__TERM_TYPE_CPU:
> > - CHECK_TYPE_VAL(NUM);
> > - if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
> > - parse_events_error__handle(err, term->err_val,
> > - strdup("too big"),
> > - NULL);
> > - return -EINVAL;
> > + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
> > + if (term->val.num >= (u64)cpu__max_present_cpu().cpu) {
> > + parse_events_error__handle(err, term->err_val,
> > + strdup("too big"),
> > + /*help=*/NULL);
> > + return -EINVAL;
> > + }
> > + } else {
> > + assert(term->type_val == PARSE_EVENTS__TERM_TYPE_STR);
> > + if (perf_pmus__find(term->val.str) == NULL) {
> > + parse_events_error__handle(err, term->err_val,
> > + strdup("not a valid PMU"),
> > + /*help=*/NULL);
> > + return -EINVAL;
> > + }
> > }
> > break;
> > case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
> > --
> > 2.50.0.727.gbf7dc18ff4-goog
> >
Hi Ian, On Wed, Jul 16, 2025 at 01:25:17PM -0700, Ian Rogers wrote: > On Wed, Jul 16, 2025 at 1:09 PM Namhyung Kim <namhyung@kernel.org> wrote: > > > > On Fri, Jun 27, 2025 at 12:24:09PM -0700, Ian Rogers wrote: > > > On hybrid systems, events like msr/tsc/ will aggregate counts across > > > all CPUs. Often metrics only want a value like msr/tsc/ for the cores > > > on which the metric is being computed. Listing each CPU with terms > > > cpu=0,cpu=1.. is laborious and would need to be encoded for all > > > variations of a CPU model. > > > > > > Allow the cpumask from a PMU to be an argument to the cpu term. For > > > example in the following the cpumask of the cstate_pkg PMU selects the > > > CPUs to count msr/tsc/ counter upon: > > > ``` > > > $ cat /sys/bus/event_source/devices/cstate_pkg/cpumask > > > 0 > > > $ perf stat -A -e 'msr/tsc,cpu=cstate_pkg/' -a sleep 0.1 > > > > It can be confusing if 'cpu' takes a number or a PMU name. What about > > adding a new term (maybe 'cpu_from') to handle this case? > > So it is possible for terms to be defined in sysfs in the 'format/' folder: > ``` > $ ls /sys/bus/event_source/devices/cpu_core/format/ > cmask edge event frontend inv ldlat offcore_rsp pc umask > ``` > By not introducing a new term we leave 'cpu_from' open for use in this > way. When I spoke to Kan we thought using the existing term made sense > and fits the idea of leaving things open for the kernel/drivers to > use. It is possible to add a new term though. Let me know and I can > update the patch and documentation accordingly. Oh, you thought about this already. It's true that it's possible to clash with PMU formats in sysfs unless we have a separate namespace for tools somehow. But that would add (maybe unnecessary) complexity. So I'm not against with this change. I just wanted to ring an alarm for potential issues. Up to you. :) Thanks, Namhyung
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