Re: [memcg] 0f12156dff: will-it-scale.per_process_ops -33.6% regression

From: Jens Axboe
Date: Tue Sep 07 2021 - 11:46:54 EST

On 9/7/21 9:07 AM, kernel test robot wrote:
> Greeting,
> FYI, we noticed a -33.6% regression of will-it-scale.per_process_ops due to commit:
> commit: 0f12156dff2862ac54235fc72703f18770769042 ("memcg: enable accounting for file lock caches")
> master

Are we at all worried about these? There's been a number of them
reported, basically for all the accounting enablements that have been
done in this merge window.

When io_uring was switched to use accounted memory, we did a bunch of
work to ameliorate the inevitable slowdowns that happen if you do
repeated allocs and/or frees and have memcg accounting enabled.

Jens Axboe