linux-kernel - Re: [PATCH] perf util: Use target->per_thread and target->system

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Message-ID: <248c18bd-b2f2-694a-e08f-989e829041ca@linux.intel.com>
Date:   Tue, 23 Jan 2018 09:08:35 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>, jolsa@...nel.org,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com>,
        kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH] perf util: Use target->per_thread and target->system_wide
 flags



On 1/23/2018 7:56 AM, Mathieu Poirier wrote:
> On 22 January 2018 at 15:15, Jin Yao <yao.jin@...ux.intel.com> wrote:
>> Mathieu Poirier reports issue in commit ("73c0ca1eee3d perf thread_map:
>> Enumerate all threads from /proc") that it has negative impact on
>> 'perf record --per-thread'. It has the effect of creating a kernel event
>> for each thread in the system for 'perf record --per-thread'.
>>
>> Mathieu Poirier's patch ("perf util: Do not reuse target->per_thread flag")
>> can fix this issue by creating a new target->all_threads flag.
>>
>> This patch is based on Mathieu Poirier's patch but it doesn't use a new
>> target->all_threads flag. This patch just uses 'target->per_thread &&
>> target->system_wide' as a condition to check for all threads case.
>>
>> Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>
>> ---
>>   tools/perf/util/evlist.c     | 2 +-
>>   tools/perf/util/thread_map.c | 4 ++--
>>   tools/perf/util/thread_map.h | 2 +-
>>   3 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
>> index 120efd8..9dff74a 100644
>> --- a/tools/perf/util/evlist.c
>> +++ b/tools/perf/util/evlist.c
>> @@ -1106,7 +1106,7 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
>>          struct thread_map *threads;
>>
>>          threads = thread_map__new_str(target->pid, target->tid, target->uid,
>> -                                     target->per_thread);
>> +                                     target->per_thread && target->system_wide);
>>
>>          if (!threads)
>>                  return -1;
>> diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
>> index 3e1038f..729dad8 100644
>> --- a/tools/perf/util/thread_map.c
>> +++ b/tools/perf/util/thread_map.c
>> @@ -323,7 +323,7 @@ struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
>>   }
>>
>>   struct thread_map *thread_map__new_str(const char *pid, const char *tid,
>> -                                      uid_t uid, bool per_thread)
>> +                                      uid_t uid, bool all_threads)
>>   {
>>          if (pid)
>>                  return thread_map__new_by_pid_str(pid);
>> @@ -331,7 +331,7 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid,
>>          if (!tid && uid != UINT_MAX)
>>                  return thread_map__new_by_uid(uid);
>>
>> -       if (per_thread)
>> +       if (all_threads)
>>                  return thread_map__new_all_cpus();
>>
>>          return thread_map__new_by_tid_str(tid);
>> diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
>> index 0a806b9..5ec91cf 100644
>> --- a/tools/perf/util/thread_map.h
>> +++ b/tools/perf/util/thread_map.h
>> @@ -31,7 +31,7 @@ struct thread_map *thread_map__get(struct thread_map *map);
>>   void thread_map__put(struct thread_map *map);
>>
>>   struct thread_map *thread_map__new_str(const char *pid,
>> -               const char *tid, uid_t uid, bool per_thread);
>> +               const char *tid, uid_t uid, bool all_threads);
>>
>>   struct thread_map *thread_map__new_by_tid_str(const char *tid_str);
> 
> Reviewed-and-tested-by: Mathieu Poirier "mathieu.poirier@...aro.org"
> 

Thanks a lot for reviewing the patch.

Thanks
Jin Yao