Re: [PATCH] ipc: remove memcg accounting for sops objects in do_semtimedop()

[Shakeel Butt]

On Sat, Sep 11, 2021 at 12:40 AM Vasily Averin <vvs@xxxxxxxxxxxxx> wrote:
>
> Linus proposes to revert an accounting for sops objects in
> do_semtimedop() because it's really just a temporary buffer
> for a single semtimedop() system call.
>
> This object can consume up to 2 pages, syscall is sleeping one,
> size and duration can be controlled by user, and this allocation
> can be repeated by many thread at the same time.
>
> However Shakeel Butt pointed that there are much more popular objects
> with the same life time and similar memory consumption, the accounting
> of which was decided to be rejected for performance reasons.
>
> In addition, any usual task consumes much more accounted memory,
> so 2 pages of this temporal buffer can be safely ignored.
>
> Link: https://patchwork.kernel.org/project/linux-fsdevel/patch/20171005222144.123797-1-shakeelb@xxxxxxxxxx/
>
> Fixes: 18319498fdd4 ("memcg: enable accounting of ipc resources")
> Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>

Thanks Vasily.

Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>