Re: [RFC PATCH v1] mm: improve call_controls_lock

SeongJae Park
2025-12-29T15:23:03Z

Hello Asier,

Thank you for sending this patch!

On Mon, 29 Dec 2025 14:55:32 +0000 Asier Gutierrez <gutierrez.asier@huawei-partners.com> wrote:

> This is a minor patch set for a call_controls_lock synchronization improvement.

Please break description lines to not exceed 75 characters per line.

>
> Spinlocks are faster than mutexes, even when the mutex takes the fast
> path. Hence, this patch replaces the mutex call_controls_lock with a spinlock.

But call_controls_lock is not being used on performance critical part.
Actually, most of DAMON code is not performance critical. I really appreciate
your patch, but I have to say I don't think this change is really needed now.
Please let me know if I'm missing something.

>
> Initial benchmarking shows the following results
>
>
> # bpftrace -e 'kprobe:kdamond_call { @start[tid] = nsecs; }

Commit log shouldn't start with '#'. Please consider indenting the above
command and below outputs of it.

Thanks,
SJ …