Re: [lkp-robot] [mm, vmscan] 5e56dfbd83: fsmark.files_per_sec -11.1% regression

From: Michal Hocko
Date: Tue Jan 24 2017 - 08:44:48 EST


On Mon 23-01-17 09:26:44, kernel test robot wrote:
>
> Greeting,
>
> FYI, we noticed a -11.1% regression of fsmark.files_per_sec due to commit:
>
>
> commit: 5e56dfbd837421b7fa3c6c06018c6701e2704917 ("mm, vmscan: consider eligible zones in get_scan_count")
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master

This is more than unexpected. This patch should be basically noop for
anything but CONFIG_HIGHMEM systems. And your config says this is 64b
kernel. Are those results reproducible? And could you try to compare
perf profiles before and after the patch.
--
Michal Hocko
SUSE Labs