[PATCH] perf record: adding dummy event before mapping

[PATCH] perf record: adding dummy event before mapping

[Mathieu Poirier]

The parameters of function 'perf_evsel__open()' in
'record_open()' have been changed to use the evsel's cpus and
threads rather than the evlist since:

commit d988d5ee6478 ("perf evlist: Open event on evsel cpus and threads")

This works fine for as long as all the events have been added to
the evlist before function 'perf_evlist__create_maps()' is called
since the latter will take care of pushing the cpus and threads of
the evlist to each of the evsel in the list.

As function 'auxtrace_record__options()' adds a "dummy:u" event to
the evlist it is important that it runs before
'perf_evlist__create_maps()'.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 tools/perf/builtin-record.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 142eeb341b29..630a7a8e3970 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1183,14 +1183,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 		goto out_symbol_exit;
 	}
 
-	err = -ENOMEM;
-	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
-		usage_with_options(record_usage, record_options);
-
 	err = auxtrace_record__options(rec->itr, rec->evlist, &rec->opts);
 	if (err)
 		goto out_symbol_exit;
 
+	err = -ENOMEM;
+	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
+		usage_with_options(record_usage, record_options);
+
 	if (record_opts__config(&rec->opts)) {
 		err = -EINVAL;
 		goto out_symbol_exit;
-- 
1.9.1

Re: [PATCH] perf record: adding dummy event before mapping

[Arnaldo Carvalho de Melo]

Em Fri, Sep 18, 2015 at 02:42:04PM -0600, Mathieu Poirier escreveu:
> The parameters of function 'perf_evsel__open()' in
> 'record_open()' have been changed to use the evsel's cpus and
> threads rather than the evlist since:
> 
> commit d988d5ee6478 ("perf evlist: Open event on evsel cpus and threads")
> 
> This works fine for as long as all the events have been added to
> the evlist before function 'perf_evlist__create_maps()' is called
> since the latter will take care of pushing the cpus and threads of
> the evlist to each of the evsel in the list.
> 
> As function 'auxtrace_record__options()' adds a "dummy:u" event to
> the evlist it is important that it runs before
> 'perf_evlist__create_maps()'.
 
What tree is this patch for? Please take a look at tip/master, there are
patches there that should address this issue, please report if not.

Namely, hey, it was already merged by Linus, see:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/log/tools

There is a set of very small patches by Adrian Hunter fixing the setting
of evsel->{cpus,threads}

Can you check with Linus's git repo? I bet you tried with 4.3-rc1?

- Arnaldo

> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
>  tools/perf/builtin-record.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 142eeb341b29..630a7a8e3970 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1183,14 +1183,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>  		goto out_symbol_exit;
>  	}
>  
> -	err = -ENOMEM;
> -	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
> -		usage_with_options(record_usage, record_options);
> -
>  	err = auxtrace_record__options(rec->itr, rec->evlist, &rec->opts);
>  	if (err)
>  		goto out_symbol_exit;
>  
> +	err = -ENOMEM;
> +	if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
> +		usage_with_options(record_usage, record_options);
> +
>  	if (record_opts__config(&rec->opts)) {
>  		err = -EINVAL;
>  		goto out_symbol_exit;
> -- 
> 1.9.1

Re: [PATCH] perf record: adding dummy event before mapping

[Mathieu Poirier]

On 18 September 2015 at 14:49, Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Em Fri, Sep 18, 2015 at 02:42:04PM -0600, Mathieu Poirier escreveu:
>> The parameters of function 'perf_evsel__open()' in
>> 'record_open()' have been changed to use the evsel's cpus and
>> threads rather than the evlist since:
>>
>> commit d988d5ee6478 ("perf evlist: Open event on evsel cpus and threads")
>>
>> This works fine for as long as all the events have been added to
>> the evlist before function 'perf_evlist__create_maps()' is called
>> since the latter will take care of pushing the cpus and threads of
>> the evlist to each of the evsel in the list.
>>
>> As function 'auxtrace_record__options()' adds a "dummy:u" event to
>> the evlist it is important that it runs before
>> 'perf_evlist__create_maps()'.
>
> What tree is this patch for? Please take a look at tip/master, there are
> patches there that should address this issue, please report if not.
>
> Namely, hey, it was already merged by Linus, see:
>
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/log/tools
>
> There is a set of very small patches by Adrian Hunter fixing the setting
> of evsel->{cpus,threads}
>
> Can you check with Linus's git repo? I bet you tried with 4.3-rc1?

Yes, it was for 4.3-rc1.  I'll try tip and will get back to you if a
problem still exists.

>
> - Arnaldo
>
>> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>> ---
>>  tools/perf/builtin-record.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
>> index 142eeb341b29..630a7a8e3970 100644
>> --- a/tools/perf/builtin-record.c
>> +++ b/tools/perf/builtin-record.c
>> @@ -1183,14 +1183,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
>>               goto out_symbol_exit;
>>       }
>>
>> -     err = -ENOMEM;
>> -     if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
>> -             usage_with_options(record_usage, record_options);
>> -
>>       err = auxtrace_record__options(rec->itr, rec->evlist, &rec->opts);
>>       if (err)
>>               goto out_symbol_exit;
>>
>> +     err = -ENOMEM;
>> +     if (perf_evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
>> +             usage_with_options(record_usage, record_options);
>> +
>>       if (record_opts__config(&rec->opts)) {
>>               err = -EINVAL;
>>               goto out_symbol_exit;
>> --
>> 1.9.1