Re: [RFCv2 00/48] perf tools: Add threads to record command
From: Alexey Budankov
Date: Fri Sep 14 2018 - 05:37:47 EST
On 14.09.2018 11:28, Jiri Olsa wrote:
> On Fri, Sep 14, 2018 at 10:26:53AM +0200, Jiri Olsa wrote:
>
> SNIP
>
>>>> The threaded monitoring currently can't monitor backward maps
>>>> and there are probably more limitations which I haven't spotted
>>>> yet.
>>>>
>>>> So far I tested on laptop:
>>>> http://people.redhat.com/~jolsa/record_threads/test-4CPU.txt
>>>>
>>>> and a one bigger server:
>>>> http://people.redhat.com/~jolsa/record_threads/test-208CPU.txt
>>>>
>>>> I can see decrease in recorded LOST events, but both the benchmark
>>>> and the monitoring must be carefully configured wrt:
>>>> - number of events (frequency)
>>>> - size of the memory maps
>>>> - size of events (callchains)
>>>> - final perf.data size
>>>>
>>>> It's also available in:
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
>>>> perf/record_threads
>>>>
>>>> thoughts? ;-) thanks
>>>> jirka
>>>
>>> It is preferable to split into smaller pieces that bring
>>> some improvement proved by metrics numbers and ready for
>>> merging and upstream. Do we have more metrics than the
>>> data loss from trace AIO patches?
>>
>> well the primary focus is to get more events in,
>> so the LOST metric is the main one
>
> actualy I was hoping, could you please run it through the same
> tests as you do for AIO code on some huge server?
Yeah, I will, but it takes some time.
>
> thanks,
> jirka
>