On 1/23/2018 10:40 PM, Jiri Olsa wrote:
On Tue, Jan 23, 2018 at 07:02:44AM +0800, Jin, Yao wrote:
SNIP
threads = thread_map__new_str(target->pid, target->tid, target->uid,
- target->per_thread);
+ target->per_thread &&
target->system_wide);
At first glance I thought your solution would do the trick but perf
record does use target->system_wide when the '-a' switch is used.
Moreover specifying the '-a' switch doesn't prevent the '--per-thread'
option from being used as well, making both target->perf_thread and
target_system_wide equal to true (and that is not good).
Although not a fan of adding more to struct target, the advantage of
having target->all_threads is that we are guaranteed that it isn't
used anywhere else.
Let me know what you think,
Mathieu
If we specify both '-a' and '--per-thread' to perf record, perf record will
override'--per-thread'. So now target->per_thread = false, and
target->system_wide = true.
If we specify '--per-thread' only to perf record, target->per_thread = true,
and target->system_wide = false.
So whatever for any case, target->per_thread && target->system_wide is
false.
Since the parameter is false, in thread_map__new_str(), it will not execute
the thread_map__new_all_cpus(). So that will not change perf record previous
behavior.
In perf stat, it allows the case that target->per_thread and
target->system_wide are all true. That means we want to collect system-wide
per-thread metrics.
could you please put this description into comment
before the thread_map__new_str is called?
thanks,
jirka
OK, I will put this comment in v2. I will send v2 soon.
Thanks
Jin Yao
