Re: [Powertop] Query: Weird Output values: Percentage over 100%

Sergey Senozhatsky <sergey.senozhatsky at gmail.com> Tue, 04 Sep 2012 15:37:45 +0300
Newsgroups dev.linux.lists.powertop
Message-ID <20120904123745.GA2993@swordfish>
On (09/04/12 11:30), Igor Zhbanov wrote:
> Arjan van de Ven wrote:
> 
> >shouldn't... the buffers are quite large....
> 
> By the way, I just curious, why events processing are limited to 5000?
> I mean the PowerTOP has f half-megabyte buffer for each type of events
> but wishes to process only 5000 even if data is there?
> 
> void perf_event::process(void *cookie)
> {
> ...
> 	while (pc->data_tail != pc->data_head && i++ < 5000) {
> ...
> 
> In the case of many cores sched:switch will be fired at least CONFIG_HZ * nr_cpus
> times per second (as I understand), and that could easily be larger than 5000.
> Especially when we measuring for several seconds.
> 

good spot.
Also interested if we will fit all perf samples on (e.g.) loaded 64 core system.

	-ss