Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
On Wed, Jul 29, 2020 at 2:43 PM Ian Rogers wrote:
>
> On Wed, Jul 29, 2020 at 11:52 AM Arnaldo Carvalho de Melo
> wrote:
> >
> > Em Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers escreveu:
> > > From: David Sharp
> > >
> > > evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
> >
> > There is no such thing as 'PERF_RECORD_PERIOD', its PERF_SAMPLE_PERIOD,
> > also...
> >
> > > from perf record options. When it is set by libpfm events, it would not
> > > get set. This changes evsel__config to see if attr->freq is set outside of
> > > whether or not it changes attr->freq itself.
> > >
> > > Signed-off-by: David Sharp
> > > Signed-off-by: Ian Rogers
> > > ---
> > > tools/perf/util/evsel.c | 7 ++-
> > > 1 file changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > > index ef802f6d40c1..811f538f7d77 100644
> > > --- a/tools/perf/util/evsel.c
> > > +++ b/tools/perf/util/evsel.c
> > > @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
> > > record_opts *opts,
> > > if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
> > >opts->user_interval != ULLONG_MAX)) {
> > > if (opts->freq) {
> > > - evsel__set_sample_bit(evsel, PERIOD);
> > > attr->freq = 1;
> > > attr->sample_freq = opts->freq;
> > > } else {
> > > attr->sample_period = opts->default_interval;
> > > }
> > > }
> > > + /*
> > > + * If attr->freq was set (here or earlier), ask for period
> > > + * to be sampled.
> > > + */
> > > + if (attr->freq)
> > > + evsel__set_sample_bit(evsel, PERIOD);
> >
> > Why can't the libpfm code set opts?
> >
> > With this patch we will end up calling evsel__set_sample_bit(evsel,
> > PERIOD) twice, which isn't a problem but looks strange.
>
> Thanks Arnaldo! The case I was looking at was something like:
> perf record --pfm-events cycles:freq=1000
>
> For regular events this would be:
> perf record -e cycles/freq=1000/
>
> With libpfm4 events the perf_event_attr is set up (a public API in
> linux/perf_event.h) and then parse_events__add_event is used (an
> internal API) to make the evsel and this added to the evlist
> (parse_libpfm_events_option). This is similar to the parse_events
> function except rather than set up a perf_event_attr the regular
> parsing sets up config terms that are then applied to evsel and attr
> later in evsel__config, via evsel__apply_config_terms.
>
> I think we can update this change so that in pfm.c after
> parse_events__add_event we do:
> if (attr.freq)
> evsel__set_sample_bit(evsel, PERIOD);
>
> This code could also be part of parse_events__add_event. I think the
> intent in placing this code here was that it is close to the similar
> evsel__apply_config_terms and setting of sample bits in the evsel. The
> logic here is already dependent on reading the attr->sample_period.
>
> I'm not sure I follow the double setting case - I think that is only
> possible with a config term or with period_set (-P).
>
> Thanks,
> Ian
Polite ping. Thanks,
Ian
>
> > - Arnaldo
> >
> > >
> > > if (opts->no_samples)
> > > attr->sample_freq = 0;
> > > --
> > > 2.28.0.163.g6104cc2f0b6-goog
> > >
> >
> > --
> >
> > - Arnaldo
Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
On Wed, Jul 29, 2020 at 11:52 AM Arnaldo Carvalho de Melo
wrote:
>
> Em Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers escreveu:
> > From: David Sharp
> >
> > evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
>
> There is no such thing as 'PERF_RECORD_PERIOD', its PERF_SAMPLE_PERIOD,
> also...
>
> > from perf record options. When it is set by libpfm events, it would not
> > get set. This changes evsel__config to see if attr->freq is set outside of
> > whether or not it changes attr->freq itself.
> >
> > Signed-off-by: David Sharp
> > Signed-off-by: Ian Rogers
> > ---
> > tools/perf/util/evsel.c | 7 ++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index ef802f6d40c1..811f538f7d77 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
> > record_opts *opts,
> > if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
> >opts->user_interval != ULLONG_MAX)) {
> > if (opts->freq) {
> > - evsel__set_sample_bit(evsel, PERIOD);
> > attr->freq = 1;
> > attr->sample_freq = opts->freq;
> > } else {
> > attr->sample_period = opts->default_interval;
> > }
> > }
> > + /*
> > + * If attr->freq was set (here or earlier), ask for period
> > + * to be sampled.
> > + */
> > + if (attr->freq)
> > + evsel__set_sample_bit(evsel, PERIOD);
>
> Why can't the libpfm code set opts?
>
> With this patch we will end up calling evsel__set_sample_bit(evsel,
> PERIOD) twice, which isn't a problem but looks strange.
Thanks Arnaldo! The case I was looking at was something like:
perf record --pfm-events cycles:freq=1000
For regular events this would be:
perf record -e cycles/freq=1000/
With libpfm4 events the perf_event_attr is set up (a public API in
linux/perf_event.h) and then parse_events__add_event is used (an
internal API) to make the evsel and this added to the evlist
(parse_libpfm_events_option). This is similar to the parse_events
function except rather than set up a perf_event_attr the regular
parsing sets up config terms that are then applied to evsel and attr
later in evsel__config, via evsel__apply_config_terms.
I think we can update this change so that in pfm.c after
parse_events__add_event we do:
if (attr.freq)
evsel__set_sample_bit(evsel, PERIOD);
This code could also be part of parse_events__add_event. I think the
intent in placing this code here was that it is close to the similar
evsel__apply_config_terms and setting of sample bits in the evsel. The
logic here is already dependent on reading the attr->sample_period.
I'm not sure I follow the double setting case - I think that is only
possible with a config term or with period_set (-P).
Thanks,
Ian
> - Arnaldo
>
> >
> > if (opts->no_samples)
> > attr->sample_freq = 0;
> > --
> > 2.28.0.163.g6104cc2f0b6-goog
> >
>
> --
>
> - Arnaldo
Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
Em Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers escreveu:
> From: David Sharp
>
> evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
There is no such thing as 'PERF_RECORD_PERIOD', its PERF_SAMPLE_PERIOD,
also...
> from perf record options. When it is set by libpfm events, it would not
> get set. This changes evsel__config to see if attr->freq is set outside of
> whether or not it changes attr->freq itself.
>
> Signed-off-by: David Sharp
> Signed-off-by: Ian Rogers
> ---
> tools/perf/util/evsel.c | 7 ++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index ef802f6d40c1..811f538f7d77 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
> record_opts *opts,
> if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
>opts->user_interval != ULLONG_MAX)) {
> if (opts->freq) {
> - evsel__set_sample_bit(evsel, PERIOD);
> attr->freq = 1;
> attr->sample_freq = opts->freq;
> } else {
> attr->sample_period = opts->default_interval;
> }
> }
> + /*
> + * If attr->freq was set (here or earlier), ask for period
> + * to be sampled.
> + */
> + if (attr->freq)
> + evsel__set_sample_bit(evsel, PERIOD);
Why can't the libpfm code set opts?
With this patch we will end up calling evsel__set_sample_bit(evsel,
PERIOD) twice, which isn't a problem but looks strange.
- Arnaldo
>
> if (opts->no_samples)
> attr->sample_freq = 0;
> --
> 2.28.0.163.g6104cc2f0b6-goog
>
--
- Arnaldo
Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
> On 28-Jul-2020, at 9:33 PM, Arnaldo Carvalho de Melo wrote:
>
> Em Tue, Jul 28, 2020 at 05:43:47PM +0200, Jiri Olsa escreveu:
>> On Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers wrote:
>>> From: David Sharp
>>>
>>> evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
>>> from perf record options. When it is set by libpfm events, it would not
>>> get set. This changes evsel__config to see if attr->freq is set outside of
>>> whether or not it changes attr->freq itself.
>>>
>>> Signed-off-by: David Sharp
>>> Signed-off-by: Ian Rogers
>>
>> Acked-by: Jiri Olsa
>
> So, somebody else complained that its not PERF_RECORD_PERIOD (there is
> no such thing) that is being set, its PERF_SAMPLE_PERIOD.
Hi Arnaldo
Thanks for adding in that correction.
Athira
>
> Since you acked it I merged it now, with that correction,
>
> - Arnaldo
>
>> thanks,
>> jirka
>>
>>> ---
>>> tools/perf/util/evsel.c | 7 ++-
>>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>>> index ef802f6d40c1..811f538f7d77 100644
>>> --- a/tools/perf/util/evsel.c
>>> +++ b/tools/perf/util/evsel.c
>>> @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
>>> record_opts *opts,
>>> if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
>>> opts->user_interval != ULLONG_MAX)) {
>>> if (opts->freq) {
>>> - evsel__set_sample_bit(evsel, PERIOD);
>>> attr->freq = 1;
>>> attr->sample_freq = opts->freq;
>>> } else {
>>> attr->sample_period = opts->default_interval;
>>> }
>>> }
>>> + /*
>>> +* If attr->freq was set (here or earlier), ask for period
>>> +* to be sampled.
>>> +*/
>>> + if (attr->freq)
>>> + evsel__set_sample_bit(evsel, PERIOD);
>>>
>>> if (opts->no_samples)
>>> attr->sample_freq = 0;
>>> --
>>> 2.28.0.163.g6104cc2f0b6-goog
>>>
>>
>
> --
>
> - Arnaldo
Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
Em Tue, Jul 28, 2020 at 05:43:47PM +0200, Jiri Olsa escreveu:
> On Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers wrote:
> > From: David Sharp
> >
> > evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
> > from perf record options. When it is set by libpfm events, it would not
> > get set. This changes evsel__config to see if attr->freq is set outside of
> > whether or not it changes attr->freq itself.
> >
> > Signed-off-by: David Sharp
> > Signed-off-by: Ian Rogers
>
> Acked-by: Jiri Olsa
So, somebody else complained that its not PERF_RECORD_PERIOD (there is
no such thing) that is being set, its PERF_SAMPLE_PERIOD.
Since you acked it I merged it now, with that correction,
- Arnaldo
> thanks,
> jirka
>
> > ---
> > tools/perf/util/evsel.c | 7 ++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index ef802f6d40c1..811f538f7d77 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
> > record_opts *opts,
> > if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
> > opts->user_interval != ULLONG_MAX)) {
> > if (opts->freq) {
> > - evsel__set_sample_bit(evsel, PERIOD);
> > attr->freq = 1;
> > attr->sample_freq = opts->freq;
> > } else {
> > attr->sample_period = opts->default_interval;
> > }
> > }
> > + /*
> > +* If attr->freq was set (here or earlier), ask for period
> > +* to be sampled.
> > +*/
> > + if (attr->freq)
> > + evsel__set_sample_bit(evsel, PERIOD);
> >
> > if (opts->no_samples)
> > attr->sample_freq = 0;
> > --
> > 2.28.0.163.g6104cc2f0b6-goog
> >
>
--
- Arnaldo
Re: [PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
On Tue, Jul 28, 2020 at 01:57:30AM -0700, Ian Rogers wrote:
> From: David Sharp
>
> evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
> from perf record options. When it is set by libpfm events, it would not
> get set. This changes evsel__config to see if attr->freq is set outside of
> whether or not it changes attr->freq itself.
>
> Signed-off-by: David Sharp
> Signed-off-by: Ian Rogers
Acked-by: Jiri Olsa
thanks,
jirka
> ---
> tools/perf/util/evsel.c | 7 ++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index ef802f6d40c1..811f538f7d77 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
> record_opts *opts,
> if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
>opts->user_interval != ULLONG_MAX)) {
> if (opts->freq) {
> - evsel__set_sample_bit(evsel, PERIOD);
> attr->freq = 1;
> attr->sample_freq = opts->freq;
> } else {
> attr->sample_period = opts->default_interval;
> }
> }
> + /*
> + * If attr->freq was set (here or earlier), ask for period
> + * to be sampled.
> + */
> + if (attr->freq)
> + evsel__set_sample_bit(evsel, PERIOD);
>
> if (opts->no_samples)
> attr->sample_freq = 0;
> --
> 2.28.0.163.g6104cc2f0b6-goog
>
[PATCH v2 1/5] perf record: Set PERF_RECORD_PERIOD if attr->freq is set.
From: David Sharp
evsel__config() would only set PERF_RECORD_PERIOD if it set attr->freq
from perf record options. When it is set by libpfm events, it would not
get set. This changes evsel__config to see if attr->freq is set outside of
whether or not it changes attr->freq itself.
Signed-off-by: David Sharp
Signed-off-by: Ian Rogers
---
tools/perf/util/evsel.c | 7 ++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ef802f6d40c1..811f538f7d77 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -979,13 +979,18 @@ void evsel__config(struct evsel *evsel, struct
record_opts *opts,
if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
opts->user_interval != ULLONG_MAX)) {
if (opts->freq) {
- evsel__set_sample_bit(evsel, PERIOD);
attr->freq = 1;
attr->sample_freq = opts->freq;
} else {
attr->sample_period = opts->default_interval;
}
}
+ /*
+* If attr->freq was set (here or earlier), ask for period
+* to be sampled.
+*/
+ if (attr->freq)
+ evsel__set_sample_bit(evsel, PERIOD);
if (opts->no_samples)
attr->sample_freq = 0;
--
2.28.0.163.g6104cc2f0b6-goog
