On 09/05/2012 05:44 AM, Sergey Senozhatsky wrote:
Hi,
On (09/05/12 15:52), Rajagopal Venkat wrote:
Incorrect timer and work perf events timestamp tracing is one of the reason for reporting usage over 100%. This patch will resolve the issue by
- rejecting the events for which entry timestamp is not recorded.
how is that possible? do you mean erasing between measurements?
schematically:
measure0:
ev1.start ev2.start ev2.end
processing clear
measure1: ev3.start ev1.end <<<<< ev3.end
processing clear
if so, then we're loosing events, which is no good. reporting less than 100% is ok, but reporting less than real is not.
p.s. I'll try to check emails, but most probably will be off-line most of the day.
-ss
Yes! This is a hard issues. Some report say CPU usage over 100% which in some cases is correct. For instance for IA, a CPU can run over 100% of it's listed frequency. For instance listed freq could be 3.4 but in turbo mode the freq govonor can request max and be given 3.8Ghz for a duration. Also overall if all processor cores are running at 100% you essentially can have a overall usage of over 100%. There have been some cases reported where CPU usage is WAY over 100% and that is an issue, but I have has a hard time reproducing the issues.
This can be tricky business, so care is needed.
-Chris
Currently these events exit timestamp itself is considered as usage period resulting in over 100% usage.
- clearing event timestamps from global map at the end of each
measurement to avoid collision with earlier recorded timestamps.
Signed-off-by: Rajagopal Venkat rajagopal.venkat@linaro.org
src/process/timer.cpp | 5 ++++- src/process/work.cpp | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/src/process/timer.cpp b/src/process/timer.cpp index 8917490..db074c4 100644 --- a/src/process/timer.cpp +++ b/src/process/timer.cpp @@ -79,7 +79,8 @@ uint64_t timer::done(uint64_t time, uint64_t timer_struct) { int64_t delta;
- if (running_since[timer_struct] > time)
- if (running_since.find(timer_struct) == running_since.end() ||
running_since[timer_struct] > time)delta = time - running_since[timer_struct]; @@ -147,6 +148,8 @@ void clear_timers(void) all_timers.erase(it); it = all_timers.begin(); }
- running_since.clear(); }
bool timer::is_deferred(void) diff --git a/src/process/work.cpp b/src/process/work.cpp index 82f13a2..e436643 100644 --- a/src/process/work.cpp +++ b/src/process/work.cpp @@ -56,7 +56,8 @@ uint64_t work::done(uint64_t time, uint64_t work_struct) { int64_t delta;
- if (running_since[work_struct] > time)
- if (running_since.find(work_struct) == running_since.end() ||
running_since[work_struct] > time)delta = time - running_since[work_struct]; @@ -102,6 +103,8 @@ void clear_work(void) all_work.erase(it); it = all_work.begin(); }
- running_since.clear(); }
-- 1.7.11.3
PowerTop mailing list PowerTop@lists.01.org https://lists.01.org/mailman/listinfo/powertop
PowerTop mailing list PowerTop@lists.01.org https://lists.01.org/mailman/listinfo/powertop