Re: [PATCH 09/10] perf/cputime: Don't stop idle tick if there's live cputime event
From: Andi Kleen
Date: Thu Jun 07 2018 - 11:45:32 EST
On Thu, Jun 07, 2018 at 12:15:12AM +0200, Jiri Olsa wrote:
> Disable stopping of the idle tick when having live cputime
> event. When the tick is disabled, the idle counts are out
> of date until next tick/update and perf cputime PMU provides
> misleading counts.
I really don't like this. This can totally change performance
(e.g. less Turbo due to less idle) and performance tools shouldn't
change the performance profile drastically.