On Wed, Feb 05, 2020 at 08:32:16PM +0800, kernel test robot wrote:
> Greeting,
> 
> FYI, we noticed a -5.5% regression of will-it-scale.per_process_ops due to commit:
> 
> 
> commit: 81ec3f3c4c4d78f2d3b6689c9816bfbdf7417dbb ("perf/x86: Add check_period PMU callback")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 

I'm fairly sure this bisect/result is bogus.