Re: [PATCH] [RFC] rcu/tree: Reduce wake up for synchronize_rcu() common case

[Joel Fernandes]

On Thu, Mar 7, 2024 at 6:48 PM Joel Fernandes (Google)
<joel@xxxxxxxxxxxxxxxxx> wrote:
>
> In the synchronize_rcu() common case, we will have less than
> SR_MAX_USERS_WAKE_FROM_GP number of users per GP. Waking up the kworker
> is pointless just to free the last injected wait head since at that point,
> all the users have already been awakened.
>
> Introduce a new counter to track this and prevent the wakeup in the
> common case.
>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
> ---

Forgot to mention, this is based on the latest RCU -dev branch and
passes light rcutorture testing on all configs. Heavier rcutorture
testing (60 minutes) was performed on TREE03.

Thanks.