Re: sched/debug: CPU hotplug operation suffers in a large cpu systems

From: Greg Kroah-Hartman
Date: Tue Nov 08 2022 - 07:24:59 EST


On Tue, Nov 08, 2022 at 03:30:46PM +0530, Vishal Chourasia wrote:
>
> Thanks Greg & Peter for your direction.
>
> While we pursue the idea of having debugfs based on kernfs, we thought about
> having a boot time parameter which would disable creating and updating of the
> sched_domain debugfs files and this would also be useful even when the kernfs
> solution kicks in, as users who may not care about these debugfs files would
> benefit from a faster CPU hotplug operation.

Ick, no, you would be adding a new user/kernel api that you will be
required to support for the next 20+ years. Just to get over a
short-term issue before you solve the problem properly.

If you really do not want these debugfs files, just disable debugfs from
your system. That should be a better short-term solution, right?

Or better yet, disable SCHED_DEBUG, why can't you do that?

thanks,

greg k-h