* [RFC PATCH v2 0/2] perf tools: Don't set inherit bit for system wide evsel
@ 2015-10-26 11:41 Wang Nan
2015-10-26 11:41 ` [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording Wang Nan
2015-10-26 11:42 ` [RFC PATCH v2 2/2] perf tools: Don't set inherit bit for system wide evsel Wang Nan
0 siblings, 2 replies; 7+ messages in thread
From: Wang Nan @ 2015-10-26 11:41 UTC (permalink / raw)
To: acme, ast, adrian.hunter; +Cc: linux-kernel, pi3orama, lizefan, Wang Nan
Previous version can be found from [1].
To make bpf_perf_event_output() and bpf_perf_event_read() easier to be
used, these two patches set inherit to 0 for system wide evsels.
After applying them, users are possible to pass system wide events to
BPF programs in following command, and don't need to consider the
setting of inherit:
# perf record -a -e evt=cycles -e ./test__map.c/maps.pmu_map.event=evt/ ...
Patch 1/2 set evsel->system_wide for system wide target. I have checked
in current evlist.c and evsel.c. The only behavior change I found is in
evlist.c:
/*
* The system_wide flag causes a selected event to be opened
* always without a pid. Consequently it will never get a
* POLLHUP, but it is used for tracking in combination with
* other events, so it should not need to be polled anyway.
* Therefore don't add it for polling.
*/
if (!evsel->system_wide &&
__perf_evlist__add_pollfd(evlist, fd, idx) < 0) {
perf_evlist__mmap_put(evlist, idx);
return -1;
}
With patch 1/2, __perf_evlist__add_pollfd() won't be called. From the
comment I pasted this modification looks harmless.
[1] http://lkml.kernel.org/r/1445597029-133332-1-git-send-email-wangnan0@huawei.com
Wang Nan (2):
perf tools: Set evsel->system_wide field for global system wide
recording
perf tools: Don't set inherit bit for system wide evsel
tools/perf/util/evsel.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--
1.8.3.4
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording
2015-10-26 11:41 [RFC PATCH v2 0/2] perf tools: Don't set inherit bit for system wide evsel Wang Nan
@ 2015-10-26 11:41 ` Wang Nan
2015-10-26 12:24 ` Adrian Hunter
2015-10-26 11:42 ` [RFC PATCH v2 2/2] perf tools: Don't set inherit bit for system wide evsel Wang Nan
1 sibling, 1 reply; 7+ messages in thread
From: Wang Nan @ 2015-10-26 11:41 UTC (permalink / raw)
To: acme, ast, adrian.hunter
Cc: linux-kernel, pi3orama, lizefan, Wang Nan,
Arnaldo Carvalho de Melo, Peter Zijlstra
evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837
(perf evlist: Add 'system_wide' option), which is used for mixing evsels
that aren't system-wide with ones that are [1]. However, for global
system wide recording (perf record -a ...), evsel->system_wide is set
to false, which is confusion.
This patch set evsel->system_wide to true if the target.system_wide is
set, which makes evsel->system_wide a reliable way to describe whether
itself is system_wide or not.
[1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Li Zefan <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org
---
tools/perf/util/evsel.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3ac4ee9c..36ecf0e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
int track = evsel->tracking;
bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
+ evsel->system_wide = opts->target.system_wide;
attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
attr->inherit = !opts->no_inherit;
--
1.8.3.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [RFC PATCH v2 2/2] perf tools: Don't set inherit bit for system wide evsel
2015-10-26 11:41 [RFC PATCH v2 0/2] perf tools: Don't set inherit bit for system wide evsel Wang Nan
2015-10-26 11:41 ` [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording Wang Nan
@ 2015-10-26 11:42 ` Wang Nan
1 sibling, 0 replies; 7+ messages in thread
From: Wang Nan @ 2015-10-26 11:42 UTC (permalink / raw)
To: acme, ast, adrian.hunter
Cc: linux-kernel, pi3orama, lizefan, Wang Nan,
Arnaldo Carvalho de Melo, Peter Zijlstra
Inherit bit is useless for a system wide evsel [1]. Further kernel
improvements are giving more constrain [2] on inherit events. This
patch set inherit bit to 0 for system wide evsels to avoid potential
constrains.
[1] http://lkml.kernel.org/r/20151022124142.GQ17308@twins.programming.kicks-ass.net
[2] http://lkml.kernel.org/r/1445559014-4667-1-git-send-email-ast@kernel.org
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Li Zefan <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/ebpf-0xsuv8wc1uwgj7qfylfolgqs@git.kernel.org
---
tools/perf/util/evsel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 36ecf0e..2a5f0f8 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -736,7 +736,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
evsel->system_wide = opts->target.system_wide;
attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
- attr->inherit = !opts->no_inherit;
+ attr->inherit = !opts->no_inherit && !evsel->system_wide;
perf_evsel__set_sample_bit(evsel, IP);
perf_evsel__set_sample_bit(evsel, TID);
--
1.8.3.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording
2015-10-26 11:41 ` [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording Wang Nan
@ 2015-10-26 12:24 ` Adrian Hunter
2015-10-26 12:39 ` Wangnan (F)
0 siblings, 1 reply; 7+ messages in thread
From: Adrian Hunter @ 2015-10-26 12:24 UTC (permalink / raw)
To: Wang Nan, acme, ast
Cc: linux-kernel, pi3orama, lizefan, Arnaldo Carvalho de Melo,
Peter Zijlstra
On 26/10/15 13:41, Wang Nan wrote:
> evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837
> (perf evlist: Add 'system_wide' option), which is used for mixing evsels
> that aren't system-wide with ones that are [1]. However, for global
> system wide recording (perf record -a ...), evsel->system_wide is set
> to false, which is confusion.
>
> This patch set evsel->system_wide to true if the target.system_wide is
> set, which makes evsel->system_wide a reliable way to describe whether
> itself is system_wide or not.
>
> [1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com
>
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Alexei Starovoitov <ast@plumgrid.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Li Zefan <lizefan@huawei.com>
> Cc: pi3orama@163.com
> Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org
> ---
> tools/perf/util/evsel.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 3ac4ee9c..36ecf0e 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
> int track = evsel->tracking;
> bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
>
> + evsel->system_wide = opts->target.system_wide;
Well that breaks the way evsel->system_wide is used i.e. it is a parameter
to the evsel and here you just overwrote it.
> attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
> attr->inherit = !opts->no_inherit;
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording
2015-10-26 12:24 ` Adrian Hunter
@ 2015-10-26 12:39 ` Wangnan (F)
2015-10-26 13:02 ` Adrian Hunter
0 siblings, 1 reply; 7+ messages in thread
From: Wangnan (F) @ 2015-10-26 12:39 UTC (permalink / raw)
To: Adrian Hunter, acme, ast
Cc: linux-kernel, pi3orama, lizefan, Arnaldo Carvalho de Melo,
Peter Zijlstra
On 2015/10/26 20:24, Adrian Hunter wrote:
> On 26/10/15 13:41, Wang Nan wrote:
>> evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837
>> (perf evlist: Add 'system_wide' option), which is used for mixing evsels
>> that aren't system-wide with ones that are [1]. However, for global
>> system wide recording (perf record -a ...), evsel->system_wide is set
>> to false, which is confusion.
>>
>> This patch set evsel->system_wide to true if the target.system_wide is
>> set, which makes evsel->system_wide a reliable way to describe whether
>> itself is system_wide or not.
>>
>> [1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com
>>
>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
>> Cc: Alexei Starovoitov <ast@plumgrid.com>
>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
>> Cc: Li Zefan <lizefan@huawei.com>
>> Cc: pi3orama@163.com
>> Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org
>> ---
>> tools/perf/util/evsel.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index 3ac4ee9c..36ecf0e 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
>> int track = evsel->tracking;
>> bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
>>
>> + evsel->system_wide = opts->target.system_wide;
> Well that breaks the way evsel->system_wide is used i.e. it is a parameter
> to the evsel and here you just overwrote it.
Currently the only user of evsel->system_wide is IPT:
auxtrace_record__options -> intel_pt_recording_options
and it only set it to true.
So I think changing to this should make it safe:
evsel->system_wide = (evsel->system_wide || opt->target.system_wide);
Thought?
If we want to add further config terms we can put it to
apply_config_terms(),
where we can implement something like:
# perf record -e cycles/system-wide/ -e instruction/no-system-wide/ ...
But currently I don't have such requirement.
Thank you.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording
2015-10-26 12:39 ` Wangnan (F)
@ 2015-10-26 13:02 ` Adrian Hunter
2015-10-27 3:23 ` Wangnan (F)
0 siblings, 1 reply; 7+ messages in thread
From: Adrian Hunter @ 2015-10-26 13:02 UTC (permalink / raw)
To: Wangnan (F), acme, ast
Cc: linux-kernel, pi3orama, lizefan, Arnaldo Carvalho de Melo,
Peter Zijlstra
On 26/10/15 14:39, Wangnan (F) wrote:
>
>
> On 2015/10/26 20:24, Adrian Hunter wrote:
>> On 26/10/15 13:41, Wang Nan wrote:
>>> evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837
>>> (perf evlist: Add 'system_wide' option), which is used for mixing evsels
>>> that aren't system-wide with ones that are [1]. However, for global
>>> system wide recording (perf record -a ...), evsel->system_wide is set
>>> to false, which is confusion.
>>>
>>> This patch set evsel->system_wide to true if the target.system_wide is
>>> set, which makes evsel->system_wide a reliable way to describe whether
>>> itself is system_wide or not.
>>>
>>> [1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com
>>>
>>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
>>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>>> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
>>> Cc: Alexei Starovoitov <ast@plumgrid.com>
>>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
>>> Cc: Li Zefan <lizefan@huawei.com>
>>> Cc: pi3orama@163.com
>>> Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org
>>> ---
>>> tools/perf/util/evsel.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>>> index 3ac4ee9c..36ecf0e 100644
>>> --- a/tools/perf/util/evsel.c
>>> +++ b/tools/perf/util/evsel.c
>>> @@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel,
>>> struct record_opts *opts)
>>> int track = evsel->tracking;
>>> bool per_cpu = opts->target.default_per_cpu &&
>>> !opts->target.per_thread;
>>> + evsel->system_wide = opts->target.system_wide;
>> Well that breaks the way evsel->system_wide is used i.e. it is a parameter
>> to the evsel and here you just overwrote it.
>
> Currently the only user of evsel->system_wide is IPT:
>
> auxtrace_record__options -> intel_pt_recording_options
>
> and it only set it to true.
>
> So I think changing to this should make it safe:
>
> evsel->system_wide = (evsel->system_wide || opt->target.system_wide);
>
> Thought?
That would work although it looks like a kludge.
Have you looked at properly validating opts->no_inherit ?
Also, aren't you neglecting target->cpu_list ?
>
> If we want to add further config terms we can put it to apply_config_terms(),
> where we can implement something like:
>
> # perf record -e cycles/system-wide/ -e instruction/no-system-wide/ ...
>
> But currently I don't have such requirement.
>
> Thank you.
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [RFC PATCH v2 1/2] perf tools: Set evsel->system_wide field for global system wide recording
2015-10-26 13:02 ` Adrian Hunter
@ 2015-10-27 3:23 ` Wangnan (F)
0 siblings, 0 replies; 7+ messages in thread
From: Wangnan (F) @ 2015-10-27 3:23 UTC (permalink / raw)
To: Adrian Hunter, acme, ast
Cc: linux-kernel, pi3orama, lizefan, Arnaldo Carvalho de Melo,
Peter Zijlstra
On 2015/10/26 21:02, Adrian Hunter wrote:
> On 26/10/15 14:39, Wangnan (F) wrote:
>>
>> On 2015/10/26 20:24, Adrian Hunter wrote:
>>> On 26/10/15 13:41, Wang Nan wrote:
>>>> evsel->system_wide is introduced by commit bf8e8f4b832972c76d64ab2e2837
>>>> (perf evlist: Add 'system_wide' option), which is used for mixing evsels
>>>> that aren't system-wide with ones that are [1]. However, for global
>>>> system wide recording (perf record -a ...), evsel->system_wide is set
>>>> to false, which is confusion.
>>>>
>>>> This patch set evsel->system_wide to true if the target.system_wide is
>>>> set, which makes evsel->system_wide a reliable way to describe whether
>>>> itself is system_wide or not.
>>>>
>>>> [1] http://lkml.kernel.org/r/562DF19B.2080608@intel.com
>>>>
>>>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
>>>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>>>> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
>>>> Cc: Alexei Starovoitov <ast@plumgrid.com>
>>>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
>>>> Cc: Li Zefan <lizefan@huawei.com>
>>>> Cc: pi3orama@163.com
>>>> Link: http://lkml.kernel.org/n/ebpf-qm3gtwidc1o5ktjd9tgjex25@git.kernel.org
>>>> ---
>>>> tools/perf/util/evsel.c | 1 +
>>>> 1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>>>> index 3ac4ee9c..36ecf0e 100644
>>>> --- a/tools/perf/util/evsel.c
>>>> +++ b/tools/perf/util/evsel.c
>>>> @@ -734,6 +734,7 @@ void perf_evsel__config(struct perf_evsel *evsel,
>>>> struct record_opts *opts)
>>>> int track = evsel->tracking;
>>>> bool per_cpu = opts->target.default_per_cpu &&
>>>> !opts->target.per_thread;
>>>> + evsel->system_wide = opts->target.system_wide;
>>> Well that breaks the way evsel->system_wide is used i.e. it is a parameter
>>> to the evsel and here you just overwrote it.
>> Currently the only user of evsel->system_wide is IPT:
>>
>> auxtrace_record__options -> intel_pt_recording_options
>>
>> and it only set it to true.
>>
>> So I think changing to this should make it safe:
>>
>> evsel->system_wide = (evsel->system_wide || opt->target.system_wide);
>>
>> Thought?
> That would work although it looks like a kludge.
>
> Have you looked at properly validating opts->no_inherit ?
>
> Also, aren't you neglecting target->cpu_list ?
I need this because Alexei's bpf_perf_event_output() helper needs perf side
support, and it only accept no-inherit perf event. I have already made a
patch[1] to support setting inherit bit per-event, so even without this and
next patch I can continue my work on bpf output. I'd like to rethink this
patch after I finish perf support for bpf output.
Thank you.
[1]
http://lkml.kernel.org/g/1445847884-143981-1-git-send-email-wangnan0@huawei.com
^ permalink raw reply [flat|nested] 7+ messages in thread
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2015-10-26 11:41 [RFC PATCH v2 0/2] perf tools: Don't set inherit bit for system wide evsel Wang Nan
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2015-10-26 12:24 ` Adrian Hunter
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2015-10-26 13:02 ` Adrian Hunter
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