diff mbox

[RFC,v2,1/2] perf tools: Set evsel->system_wide field for global system wide recording

Message ID 1445859720-146146-2-git-send-email-wangnan0@huawei.com
State New
Headers show

Commit Message

Wang Nan Oct. 26, 2015, 11:41 a.m. UTC
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(+)

-- 
1.8.3.4

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Comments

Wang Nan Oct. 26, 2015, 12:39 p.m. UTC | #1
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.

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Wang Nan Oct. 27, 2015, 3:23 a.m. UTC | #2
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

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diff mbox

Patch

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;