Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1704018
| From | Alexey Budankov <alexey.budankov@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt |
| Date | 2017-08-04 16:30 +0200 |
| Message-ID | <uaLLX-89C-9@gated-at.bofh.it> (permalink) |
| References | <u9X2N-7mD-15@gated-at.bofh.it> <u9X2O-7mD-25@gated-at.bofh.it> <uapVc-1If-91@gated-at.bofh.it> <uatm2-3Td-5@gated-at.bofh.it> <uaK3x-6XA-27@gated-at.bofh.it> |
| Organization | Intel Corp. |
On 04.08.2017 15:35, Peter Zijlstra wrote:
> On Thu, Aug 03, 2017 at 09:47:56PM +0300, Alexey Budankov wrote:
>> On 03.08.2017 18:00, Peter Zijlstra wrote:
>
>>> Are the magic spots, right? And I'm not convinced its right.
>>>
>>> Suppose I have two events in my context, and I created them 1 minute
>>> apart. Then their respective tstamp_enabled are 1 minute apart as well.
>>> But the above doesn't seem to preserve that difference.
>>>
>>> A similar argument can be made for running I think. That is a per event
>>> value and cannot be passed along to the ctx and back.
>>
>> Aww, I see your point and it challenges my initial assumptions.
>> Let me think thru the case more. There must be some solution. Thanks!
>
> So the sensible thing is probably to rewrite the entire time tracking to
> make more sense. OTOH that's also the riskiest.
>
> Something like:
>
> __update_state_and_time(event, new_state)
> {
> u64 delta, now = perf_event_time(event);
> int old_state = event->state;
>
> event->tstamp = now;
> event->state = new_state;
>
> delta = now - event->tstamp;
> switch (state) {
> case STATE_ACTIVE:
> WARN_ON_ONCE(old_state != STATE_INACTIVE);
> event->total_time_enabled += delta;
> break;
>
> case STATE_INACTIVE:
> switch (old_state) {
> case STATE_OFF:
> /* ignore the OFF -> INACTIVE period */
> break;
>
> case STATE_ACTIVE:
> event->total_time_enabled += delta;
> event->total_time_running += delta;
> break;
>
> default:
> WARN_ONCE();
> }
> break;
>
> case STATE_OFF:
> WARN_ON_ONCE(old_state != STATE_INACTIVE)
> event->total_time_enabled += delta;
> break;
> }
> }
>
> __read_curent_times(event, u64 *enabled, u64 *running)
> {
> u64 delta, now = perf_event_time(event);
>
> delta = now - event->tstamp;
>
> *enabled = event->total_time_enabled;
> if (event->state >= STATE_INACTIVE)
> *enabled += delta;
> *running = event->total_time_running
> if (event->state == STATE_ACTIVE)
> *running += delta;
> }
>
> perhaps? That instantly solves the problem I think, because now we don't
> need to update inactive events. But maybe I missed some, could you
> verify?
Thanks for the input. I will check it.
>
>
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v6 0/3] perf/core: addressing 4x slowdown during per-process profiling of STREAM benchmark on Intel Xeon Phi Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-02 10:20 +0200
[PATCH v6 3/3]: perf/core: add mux switch to skip to the current CPU's events list on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-02 10:20 +0200
[PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-02 10:20 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-03 15:10 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-03 16:10 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-03 18:00 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-04 14:40 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-03 17:10 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-03 20:50 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-04 14:40 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Peter Zijlstra <peterz@infradead.org> - 2017-08-04 15:00 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-04 16:30 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-04 16:30 +0200
Re: [PATCH v6 2/3]: perf/core: use context tstamp_data for skipped events on mux interrupt Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-10 18:00 +0200
[PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-02 10:20 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-03 15:10 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-03 22:40 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-04 16:40 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-07 09:20 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-07 10:40 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-07 11:20 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-07 17:40 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-07 18:00 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-07 18:30 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-07 19:00 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Andi Kleen <ak@linux.intel.com> - 2017-08-07 19:50 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-07 20:20 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-07 20:20 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Peter Zijlstra <peterz@infradead.org> - 2017-08-04 17:00 +0200
Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups Alexey Budankov <alexey.budankov@linux.intel.com> - 2017-08-07 17:30 +0200
csiph-web