[PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jin Yao]

Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
a dummy event is added to capture mmaps.

But if we run perf-record as,

 # perf record -e cycles:p -IXMM0 -a -- sleep 1
 Error:
 dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'

The issue is, if we enable the extended regs (-IXMM0), but the
pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
will return -EOPNOTSUPP error.

See following code pieces.

/* in kernel/events/core.c */
static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)

{
	....
	if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
	    has_extended_regs(event))
		ret = -EOPNOTSUPP;
	....
}

For software dummy event, the PMU should be not set with
PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
event has possibility to be set with PERF_REG_EXTENDED_MASK bit.

In evsel__config, /* tools/perf/util/evsel.c */

if (opts->sample_intr_regs) {
	attr->sample_regs_intr = opts->sample_intr_regs;
}

If we use -IXMM0, the attr>sample_regs_intr will be set with
PERF_REG_EXTENDED_MASK bit.

It doesn't make sense to set attr->sample_regs_intr for a
software dummy event.

This patch adds dummy event checking before setting
attr->sample_regs_intr.

After:
  # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]

Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/util/evsel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 96e5171dce41..df3315543e86 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
 	if (callchain && callchain->enabled && !evsel->no_aux_samples)
 		evsel__config_callchain(evsel, opts, callchain);
 
-	if (opts->sample_intr_regs) {
+	if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
 		attr->sample_regs_intr = opts->sample_intr_regs;
 		evsel__set_sample_bit(evsel, REGS_INTR);
 	}
 
-	if (opts->sample_user_regs) {
+	if (opts->sample_user_regs && !is_dummy_event(evsel)) {
 		attr->sample_regs_user |= opts->sample_user_regs;
 		evsel__set_sample_bit(evsel, REGS_USER);
 	}
-- 
2.17.1

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jiri Olsa]

On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
> a dummy event is added to capture mmaps.
> 
> But if we run perf-record as,
> 
>  # perf record -e cycles:p -IXMM0 -a -- sleep 1
>  Error:
>  dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
> 
> The issue is, if we enable the extended regs (-IXMM0), but the
> pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
> will return -EOPNOTSUPP error.
> 
> See following code pieces.
> 
> /* in kernel/events/core.c */
> static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
> 
> {
> 	....
> 	if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
> 	    has_extended_regs(event))
> 		ret = -EOPNOTSUPP;
> 	....
> }
> 
> For software dummy event, the PMU should be not set with
> PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
> event has possibility to be set with PERF_REG_EXTENDED_MASK bit.
> 
> In evsel__config, /* tools/perf/util/evsel.c */
> 
> if (opts->sample_intr_regs) {
> 	attr->sample_regs_intr = opts->sample_intr_regs;
> }
> 
> If we use -IXMM0, the attr>sample_regs_intr will be set with
> PERF_REG_EXTENDED_MASK bit.
> 
> It doesn't make sense to set attr->sample_regs_intr for a
> software dummy event.
> 
> This patch adds dummy event checking before setting
> attr->sample_regs_intr.
> 
> After:
>   # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]

LGTM, Adrian (cc-ed) just added another check to the same place,
but it looks like both of them should be there:

  https://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com/

jirka

> 
> Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> ---
>  tools/perf/util/evsel.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 96e5171dce41..df3315543e86 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
>  	if (callchain && callchain->enabled && !evsel->no_aux_samples)
>  		evsel__config_callchain(evsel, opts, callchain);
>  
> -	if (opts->sample_intr_regs) {
> +	if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
>  		attr->sample_regs_intr = opts->sample_intr_regs;
>  		evsel__set_sample_bit(evsel, REGS_INTR);
>  	}
>  
> -	if (opts->sample_user_regs) {
> +	if (opts->sample_user_regs && !is_dummy_event(evsel)) {
>  		attr->sample_regs_user |= opts->sample_user_regs;
>  		evsel__set_sample_bit(evsel, REGS_USER);
>  	}
> -- 
> 2.17.1
> 

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jin, Yao]

Hi Jiri,

On 7/3/2020 7:00 PM, Jiri Olsa wrote:
> On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
>> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
>> a dummy event is added to capture mmaps.
>>
>> But if we run perf-record as,
>>
>>   # perf record -e cycles:p -IXMM0 -a -- sleep 1
>>   Error:
>>   dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
>>
>> The issue is, if we enable the extended regs (-IXMM0), but the
>> pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
>> will return -EOPNOTSUPP error.
>>
>> See following code pieces.
>>
>> /* in kernel/events/core.c */
>> static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
>>
>> {
>> 	....
>> 	if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
>> 	    has_extended_regs(event))
>> 		ret = -EOPNOTSUPP;
>> 	....
>> }
>>
>> For software dummy event, the PMU should be not set with
>> PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
>> event has possibility to be set with PERF_REG_EXTENDED_MASK bit.
>>
>> In evsel__config, /* tools/perf/util/evsel.c */
>>
>> if (opts->sample_intr_regs) {
>> 	attr->sample_regs_intr = opts->sample_intr_regs;
>> }
>>
>> If we use -IXMM0, the attr>sample_regs_intr will be set with
>> PERF_REG_EXTENDED_MASK bit.
>>
>> It doesn't make sense to set attr->sample_regs_intr for a
>> software dummy event.
>>
>> This patch adds dummy event checking before setting
>> attr->sample_regs_intr.
>>
>> After:
>>    # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
>>    [ perf record: Woken up 1 times to write data ]
>>    [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]
> 
> LGTM, Adrian (cc-ed) just added another check to the same place,
> but it looks like both of them should be there:
> 
>    https://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com/
> 
> jirka
> 

Thanks Jiri! Yes, it looks like both of checks should be added here.

So do I post v2 (just rebase) once Adrian's patch gets merged?

Thanks
Jin Yao

>>
>> Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>> ---
>>   tools/perf/util/evsel.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index 96e5171dce41..df3315543e86 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
>>   	if (callchain && callchain->enabled && !evsel->no_aux_samples)
>>   		evsel__config_callchain(evsel, opts, callchain);
>>   
>> -	if (opts->sample_intr_regs) {
>> +	if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
>>   		attr->sample_regs_intr = opts->sample_intr_regs;
>>   		evsel__set_sample_bit(evsel, REGS_INTR);
>>   	}
>>   
>> -	if (opts->sample_user_regs) {
>> +	if (opts->sample_user_regs && !is_dummy_event(evsel)) {
>>   		attr->sample_regs_user |= opts->sample_user_regs;
>>   		evsel__set_sample_bit(evsel, REGS_USER);
>>   	}
>> -- 
>> 2.17.1
>>
> 

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Ian Rogers]

On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
>
> Hi Jiri,
>
> On 7/3/2020 7:00 PM, Jiri Olsa wrote:
> > On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
> >> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
> >> a dummy event is added to capture mmaps.
> >>
> >> But if we run perf-record as,
> >>
> >>   # perf record -e cycles:p -IXMM0 -a -- sleep 1
> >>   Error:
> >>   dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
> >>

Sorry for the breakage caused by modifying the dummy event. Could we
add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
with:

$ perf record -e cycles:p -IAX -a -- sleep 1

succeeds.

Thanks,
Ian

> >> The issue is, if we enable the extended regs (-IXMM0), but the
> >> pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
> >> will return -EOPNOTSUPP error.
> >>
> >> See following code pieces.
> >>
> >> /* in kernel/events/core.c */
> >> static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
> >>
> >> {
> >>      ....
> >>      if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
> >>          has_extended_regs(event))
> >>              ret = -EOPNOTSUPP;
> >>      ....
> >> }
> >>
> >> For software dummy event, the PMU should be not set with
> >> PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
> >> event has possibility to be set with PERF_REG_EXTENDED_MASK bit.
> >>
> >> In evsel__config, /* tools/perf/util/evsel.c */
> >>
> >> if (opts->sample_intr_regs) {
> >>      attr->sample_regs_intr = opts->sample_intr_regs;
> >> }
> >>
> >> If we use -IXMM0, the attr>sample_regs_intr will be set with
> >> PERF_REG_EXTENDED_MASK bit.
> >>
> >> It doesn't make sense to set attr->sample_regs_intr for a
> >> software dummy event.
> >>
> >> This patch adds dummy event checking before setting
> >> attr->sample_regs_intr.
> >>
> >> After:
> >>    # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
> >>    [ perf record: Woken up 1 times to write data ]
> >>    [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]
> >
> > LGTM, Adrian (cc-ed) just added another check to the same place,
> > but it looks like both of them should be there:
> >
> >    https://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com/
> >
> > jirka
> >
>
> Thanks Jiri! Yes, it looks like both of checks should be added here.
>
> So do I post v2 (just rebase) once Adrian's patch gets merged?
>
> Thanks
> Jin Yao
>
> >>
> >> Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
> >> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> >> ---
> >>   tools/perf/util/evsel.c | 4 ++--
> >>   1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> >> index 96e5171dce41..df3315543e86 100644
> >> --- a/tools/perf/util/evsel.c
> >> +++ b/tools/perf/util/evsel.c
> >> @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
> >>      if (callchain && callchain->enabled && !evsel->no_aux_samples)
> >>              evsel__config_callchain(evsel, opts, callchain);
> >>
> >> -    if (opts->sample_intr_regs) {
> >> +    if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
> >>              attr->sample_regs_intr = opts->sample_intr_regs;
> >>              evsel__set_sample_bit(evsel, REGS_INTR);
> >>      }
> >>
> >> -    if (opts->sample_user_regs) {
> >> +    if (opts->sample_user_regs && !is_dummy_event(evsel)) {
> >>              attr->sample_regs_user |= opts->sample_user_regs;
> >>              evsel__set_sample_bit(evsel, REGS_USER);
> >>      }
> >> --
> >> 2.17.1
> >>
> >

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jin, Yao]

Hi Ian,

On 7/6/2020 8:47 AM, Ian Rogers wrote:
> On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
>>
>> Hi Jiri,
>>
>> On 7/3/2020 7:00 PM, Jiri Olsa wrote:
>>> On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
>>>> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
>>>> a dummy event is added to capture mmaps.
>>>>
>>>> But if we run perf-record as,
>>>>
>>>>    # perf record -e cycles:p -IXMM0 -a -- sleep 1
>>>>    Error:
>>>>    dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
>>>>
> 
> Sorry for the breakage caused by modifying the dummy event. Could we
> add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
> Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
> with:
> 
> $ perf record -e cycles:p -IAX -a -- sleep 1
> 
> succeeds.
> 
> Thanks,
> Ian
> 

-IAX should be no problem. The issue only occurs on the platform with extended regs supports, such 
as ICL. So I don't know if it's suitable to add it to perf test suite.

Thanks
Jin Yao

>>>> The issue is, if we enable the extended regs (-IXMM0), but the
>>>> pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
>>>> will return -EOPNOTSUPP error.
>>>>
>>>> See following code pieces.
>>>>
>>>> /* in kernel/events/core.c */
>>>> static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
>>>>
>>>> {
>>>>       ....
>>>>       if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
>>>>           has_extended_regs(event))
>>>>               ret = -EOPNOTSUPP;
>>>>       ....
>>>> }
>>>>
>>>> For software dummy event, the PMU should be not set with
>>>> PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
>>>> event has possibility to be set with PERF_REG_EXTENDED_MASK bit.
>>>>
>>>> In evsel__config, /* tools/perf/util/evsel.c */
>>>>
>>>> if (opts->sample_intr_regs) {
>>>>       attr->sample_regs_intr = opts->sample_intr_regs;
>>>> }
>>>>
>>>> If we use -IXMM0, the attr>sample_regs_intr will be set with
>>>> PERF_REG_EXTENDED_MASK bit.
>>>>
>>>> It doesn't make sense to set attr->sample_regs_intr for a
>>>> software dummy event.
>>>>
>>>> This patch adds dummy event checking before setting
>>>> attr->sample_regs_intr.
>>>>
>>>> After:
>>>>     # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
>>>>     [ perf record: Woken up 1 times to write data ]
>>>>     [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]
>>>
>>> LGTM, Adrian (cc-ed) just added another check to the same place,
>>> but it looks like both of them should be there:
>>>
>>>     https://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com/
>>>
>>> jirka
>>>
>>
>> Thanks Jiri! Yes, it looks like both of checks should be added here.
>>
>> So do I post v2 (just rebase) once Adrian's patch gets merged?
>>
>> Thanks
>> Jin Yao
>>
>>>>
>>>> Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
>>>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>>>> ---
>>>>    tools/perf/util/evsel.c | 4 ++--
>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>>>> index 96e5171dce41..df3315543e86 100644
>>>> --- a/tools/perf/util/evsel.c
>>>> +++ b/tools/perf/util/evsel.c
>>>> @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
>>>>       if (callchain && callchain->enabled && !evsel->no_aux_samples)
>>>>               evsel__config_callchain(evsel, opts, callchain);
>>>>
>>>> -    if (opts->sample_intr_regs) {
>>>> +    if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
>>>>               attr->sample_regs_intr = opts->sample_intr_regs;
>>>>               evsel__set_sample_bit(evsel, REGS_INTR);
>>>>       }
>>>>
>>>> -    if (opts->sample_user_regs) {
>>>> +    if (opts->sample_user_regs && !is_dummy_event(evsel)) {
>>>>               attr->sample_regs_user |= opts->sample_user_regs;
>>>>               evsel__set_sample_bit(evsel, REGS_USER);
>>>>       }
>>>> --
>>>> 2.17.1
>>>>
>>>

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jin, Yao]

Hi,

On 7/6/2020 8:55 AM, Jin, Yao wrote:
> Hi Ian,
> 
> On 7/6/2020 8:47 AM, Ian Rogers wrote:
>> On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
>>>
>>> Hi Jiri,
>>>
>>> On 7/3/2020 7:00 PM, Jiri Olsa wrote:
>>>> On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
>>>>> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
>>>>> a dummy event is added to capture mmaps.
>>>>>
>>>>> But if we run perf-record as,
>>>>>
>>>>>    # perf record -e cycles:p -IXMM0 -a -- sleep 1
>>>>>    Error:
>>>>>    dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
>>>>>
>>
>> Sorry for the breakage caused by modifying the dummy event. Could we
>> add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
>> Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
>> with:
>>
>> $ perf record -e cycles:p -IAX -a -- sleep 1
>>
>> succeeds.
>>
>> Thanks,
>> Ian
>>
> 
> -IAX should be no problem. The issue only occurs on the platform with extended regs supports, such 
> as ICL. So I don't know if it's suitable to add it to perf test suite.
> 
> Thanks
> Jin Yao
> 

Can this fix patch be accepted?

Thanks
Jin Yao

>>>>> The issue is, if we enable the extended regs (-IXMM0), but the
>>>>> pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
>>>>> will return -EOPNOTSUPP error.
>>>>>
>>>>> See following code pieces.
>>>>>
>>>>> /* in kernel/events/core.c */
>>>>> static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
>>>>>
>>>>> {
>>>>>       ....
>>>>>       if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
>>>>>           has_extended_regs(event))
>>>>>               ret = -EOPNOTSUPP;
>>>>>       ....
>>>>> }
>>>>>
>>>>> For software dummy event, the PMU should be not set with
>>>>> PERF_PMU_CAP_EXTENDED_REGS. But unfortunately in current code, the dummy
>>>>> event has possibility to be set with PERF_REG_EXTENDED_MASK bit.
>>>>>
>>>>> In evsel__config, /* tools/perf/util/evsel.c */
>>>>>
>>>>> if (opts->sample_intr_regs) {
>>>>>       attr->sample_regs_intr = opts->sample_intr_regs;
>>>>> }
>>>>>
>>>>> If we use -IXMM0, the attr>sample_regs_intr will be set with
>>>>> PERF_REG_EXTENDED_MASK bit.
>>>>>
>>>>> It doesn't make sense to set attr->sample_regs_intr for a
>>>>> software dummy event.
>>>>>
>>>>> This patch adds dummy event checking before setting
>>>>> attr->sample_regs_intr.
>>>>>
>>>>> After:
>>>>>     # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
>>>>>     [ perf record: Woken up 1 times to write data ]
>>>>>     [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]
>>>>
>>>> LGTM, Adrian (cc-ed) just added another check to the same place,
>>>> but it looks like both of them should be there:
>>>>
>>>>     https://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com/
>>>>
>>>> jirka
>>>>
>>>
>>> Thanks Jiri! Yes, it looks like both of checks should be added here.
>>>
>>> So do I post v2 (just rebase) once Adrian's patch gets merged?
>>>
>>> Thanks
>>> Jin Yao
>>>
>>>>>
>>>>> Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
>>>>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>>>>> ---
>>>>>    tools/perf/util/evsel.c | 4 ++--
>>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>>>>> index 96e5171dce41..df3315543e86 100644
>>>>> --- a/tools/perf/util/evsel.c
>>>>> +++ b/tools/perf/util/evsel.c
>>>>> @@ -1020,12 +1020,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
>>>>>       if (callchain && callchain->enabled && !evsel->no_aux_samples)
>>>>>               evsel__config_callchain(evsel, opts, callchain);
>>>>>
>>>>> -    if (opts->sample_intr_regs) {
>>>>> +    if (opts->sample_intr_regs && !is_dummy_event(evsel)) {
>>>>>               attr->sample_regs_intr = opts->sample_intr_regs;
>>>>>               evsel__set_sample_bit(evsel, REGS_INTR);
>>>>>       }
>>>>>
>>>>> -    if (opts->sample_user_regs) {
>>>>> +    if (opts->sample_user_regs && !is_dummy_event(evsel)) {
>>>>>               attr->sample_regs_user |= opts->sample_user_regs;
>>>>>               evsel__set_sample_bit(evsel, REGS_USER);
>>>>>       }
>>>>> -- 
>>>>> 2.17.1
>>>>>
>>>>

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jiri Olsa]

On Fri, Jul 17, 2020 at 11:33:46AM +0800, Jin, Yao wrote:
> Hi,
> 
> On 7/6/2020 8:55 AM, Jin, Yao wrote:
> > Hi Ian,
> > 
> > On 7/6/2020 8:47 AM, Ian Rogers wrote:
> > > On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
> > > > 
> > > > Hi Jiri,
> > > > 
> > > > On 7/3/2020 7:00 PM, Jiri Olsa wrote:
> > > > > On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
> > > > > > Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
> > > > > > a dummy event is added to capture mmaps.
> > > > > > 
> > > > > > But if we run perf-record as,
> > > > > > 
> > > > > >    # perf record -e cycles:p -IXMM0 -a -- sleep 1
> > > > > >    Error:
> > > > > >    dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
> > > > > > 
> > > 
> > > Sorry for the breakage caused by modifying the dummy event. Could we
> > > add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
> > > Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
> > > with:
> > > 
> > > $ perf record -e cycles:p -IAX -a -- sleep 1
> > > 
> > > succeeds.
> > > 
> > > Thanks,
> > > Ian
> > > 
> > 
> > -IAX should be no problem. The issue only occurs on the platform with
> > extended regs supports, such as ICL. So I don't know if it's suitable to
> > add it to perf test suite.
> > 
> > Thanks
> > Jin Yao
> > 
> 
> Can this fix patch be accepted?

hi,
my only concern was that it would conflict with Adrian's patch,
other than that:

Acked-by: Jiri Olsa <jolsa@redhat.com>

thanks,
jirka

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Jin, Yao]

On 7/17/2020 4:24 PM, Jiri Olsa wrote:
> On Fri, Jul 17, 2020 at 11:33:46AM +0800, Jin, Yao wrote:
>> Hi,
>>
>> On 7/6/2020 8:55 AM, Jin, Yao wrote:
>>> Hi Ian,
>>>
>>> On 7/6/2020 8:47 AM, Ian Rogers wrote:
>>>> On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
>>>>>
>>>>> Hi Jiri,
>>>>>
>>>>> On 7/3/2020 7:00 PM, Jiri Olsa wrote:
>>>>>> On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
>>>>>>> Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
>>>>>>> a dummy event is added to capture mmaps.
>>>>>>>
>>>>>>> But if we run perf-record as,
>>>>>>>
>>>>>>>     # perf record -e cycles:p -IXMM0 -a -- sleep 1
>>>>>>>     Error:
>>>>>>>     dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
>>>>>>>
>>>>
>>>> Sorry for the breakage caused by modifying the dummy event. Could we
>>>> add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
>>>> Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
>>>> with:
>>>>
>>>> $ perf record -e cycles:p -IAX -a -- sleep 1
>>>>
>>>> succeeds.
>>>>
>>>> Thanks,
>>>> Ian
>>>>
>>>
>>> -IAX should be no problem. The issue only occurs on the platform with
>>> extended regs supports, such as ICL. So I don't know if it's suitable to
>>> add it to perf test suite.
>>>
>>> Thanks
>>> Jin Yao
>>>
>>
>> Can this fix patch be accepted?
> 
> hi,
> my only concern was that it would conflict with Adrian's patch,
> other than that:
> 
> Acked-by: Jiri Olsa <jolsa@redhat.com>
> 
> thanks,
> jirka
> 

Thanks Jiri!

Adrian's patch has not been merged otherwise I can rebase my patch on top of Adrian's patch.

Thanks
Jin Yao

Re: [PATCH] perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

[Arnaldo Carvalho de Melo]

Em Fri, Jul 17, 2020 at 04:30:21PM +0800, Jin, Yao escreveu:
> 
> 
> On 7/17/2020 4:24 PM, Jiri Olsa wrote:
> > On Fri, Jul 17, 2020 at 11:33:46AM +0800, Jin, Yao wrote:
> > > Hi,
> > > 
> > > On 7/6/2020 8:55 AM, Jin, Yao wrote:
> > > > Hi Ian,
> > > > 
> > > > On 7/6/2020 8:47 AM, Ian Rogers wrote:
> > > > > On Fri, Jul 3, 2020 at 5:31 PM Jin, Yao <yao.jin@linux.intel.com> wrote:
> > > > > > 
> > > > > > Hi Jiri,
> > > > > > 
> > > > > > On 7/3/2020 7:00 PM, Jiri Olsa wrote:
> > > > > > > On Fri, Jul 03, 2020 at 08:42:15AM +0800, Jin Yao wrote:
> > > > > > > > Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
> > > > > > > > a dummy event is added to capture mmaps.
> > > > > > > > 
> > > > > > > > But if we run perf-record as,
> > > > > > > > 
> > > > > > > >     # perf record -e cycles:p -IXMM0 -a -- sleep 1
> > > > > > > >     Error:
> > > > > > > >     dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
> > > > > > > > 
> > > > > 
> > > > > Sorry for the breakage caused by modifying the dummy event. Could we
> > > > > add a test to cover the issue? Perhaps in tools/perf/tests/shell/.
> > > > > Trying to reproduce with a register on my skylakex on a 5.6.14 kernel
> > > > > with:
> > > > > 
> > > > > $ perf record -e cycles:p -IAX -a -- sleep 1
> > > > > 
> > > > > succeeds.
> > > > > 
> > > > > Thanks,
> > > > > Ian
> > > > > 
> > > > 
> > > > -IAX should be no problem. The issue only occurs on the platform with
> > > > extended regs supports, such as ICL. So I don't know if it's suitable to
> > > > add it to perf test suite.
> > > > 
> > > > Thanks
> > > > Jin Yao
> > > > 
> > > 
> > > Can this fix patch be accepted?
> > 
> > hi,
> > my only concern was that it would conflict with Adrian's patch,
> > other than that:
> > 
> > Acked-by: Jiri Olsa <jolsa@redhat.com>
> > 
> > thanks,
> > jirka
> > 
> 
> Thanks Jiri!
> 
> Adrian's patch has not been merged otherwise I can rebase my patch on top of Adrian's patch.

I'll check this today.

- Arnaldo