Re: [LKP] [mm] ac5b2c1891: vm-scalability.throughput -61.3% regression

[Linus Torvalds]

On Mon, Nov 26, 2018 at 10:24 PM kernel test robot
<rong.a.chen@xxxxxxxxx> wrote:
>
> FYI, we noticed a -61.3% regression of vm-scalability.throughput due
> to commit ac5b2c18911f ("mm: thp: relax __GFP_THISNODE for
> MADV_HUGEPAGE mappings")

Well, that's certainly noticeable and not good.

Andrea, I suspect it might be causing fights with auto numa migration..

Lots more system time, but also look at this:

>    1122389 Â  9%     +17.2%    1315380 Â  4%  proc-vmstat.numa_hit
>     214722 Â  5%     +21.6%     261076 Â  3%  proc-vmstat.numa_huge_pte_updates
>    1108142 Â  9%     +17.4%    1300857 Â  4%  proc-vmstat.numa_local
>     145368 Â 48%     +63.1%     237050 Â 17%  proc-vmstat.numa_miss
>     159615 Â 44%     +57.6%     251573 Â 16%  proc-vmstat.numa_other
>     185.50 Â 81%   +8278.6%      15542 Â 40%  proc-vmstat.numa_pages_migrated

Should the commit be reverted? Or perhaps at least modified?

                     Linus