lkml.org 
[lkml]   [2019]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 4/9] perf/x86/intel: Support hardware TopDown metrics
Date


On 5/28/2019 9:48 AM, Peter Zijlstra wrote:
> On Tue, May 21, 2019 at 02:40:50PM -0700, kan.liang@linux.intel.com wrote:
>> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
>> index b980b9e95d2a..0d7081434d1d 100644
>> --- a/include/linux/perf_event.h
>> +++ b/include/linux/perf_event.h
>> @@ -133,6 +133,11 @@ struct hw_perf_event {
>>
>> struct hw_perf_event_extra extra_reg;
>> struct hw_perf_event_extra branch_reg;
>> +
>> + u64 saved_metric;
>> + u64 saved_slots;
>> + u64 last_slots;
>> + u64 last_metric;
>
> This is really sad, and I'm thinking much of that really isn't needed
> anyway, due to how you're not using some of the other fields.

If we don't cache the value, we have to update all metrics events when
reading any metrics event. I think that could bring high overhead.

Thanks,
Kan
>
>> };
>> struct { /* software */
>> struct hrtimer hrtimer;
>> --
>> 2.14.5
>>

\
 
 \ /
  Last update: 2019-05-28 20:25    [W:0.072 / U:1.692 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site