Re: [PATCH v5 06/18] rcu: Introduce call_rcu_lazy() API implementation

[Frederic Weisbecker]

On Tue, Sep 06, 2022 at 10:56:01PM -0400, Joel Fernandes wrote:
> On the issue of regressions with non-lazy things being treated as lazy, I was
> thinking of adding a bounded-time-check to:
> 
> [PATCH v5 08/18] rcu: Add per-CB tracing for queuing, flush and invocation.
> 
> Where, if a non-lazy CB takes an abnormally long time to execute (say it was
> subject to a race-condition), it would splat. This can be done because I am
> tracking the queue-time in the rcu_head in that patch.
> 
> On another note, boot time regressions show up pretty quickly (at least on
> ChromeOS) when non-lazy things become lazy and so far with the latest code it
> has fortunately been pretty well behaved.

Makes sense. We definetly need some sort of detection for delayed non-lazy
callbacks.

Thanks!

> 
> Thanks,
> 
>  - Joel