Re: [PATCH] sched: Warn on long periods of pending need_resched

[Josh Don]

On Fri, Mar 19, 2021 at 2:02 AM Mel Gorman <mgorman@xxxxxxx> wrote:
>
> Default disabling and hidden behind a static branch would be useful
> because the majority of users are not going to know what to do about
> a need_resched warning and the sysctl is not documented. As Ingo said,
> SCHED_DEBUG is enabled by default a lot. While I'm not sure what motivates
> most distributions, I have found it useful to display topology information
> on boot and in rare cases, for the enabling/disabling of sched features.
> Hence, sched debug features should avoid adding too much overhead where
> possible.
>
> The static branch would mean splitting the very large inline functions
> adding by the patch. The inline section should do a static check only and
> do the main work in a function in kernel/sched/debug.c so it has minimal
> overhead if unused.
>
> --
> Mel Gorman
> SUSE Labs

Makes sense, I'll include this in v2.

Thanks,
Josh