Re: [PATCH v3 3/7] doc: Add rcutree.rcu_normal_wake_from_gp to kernel-parameters.txt

From: Paul E. McKenney
Date: Tue Dec 19 2023 - 20:17:27 EST


On Tue, Nov 28, 2023 at 09:00:29AM +0100, Uladzislau Rezki (Sony) wrote:
> This commit adds rcutree.rcu_normal_wake_from_gp description
> to the kernel-parameters.txt file.
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>

Very good, but could you please fold this into the first patch, which
is the one that adds this kernel parameter?

Thanx, Paul

> ---
> Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 0a1731a0f0ef..65bfbfb09522 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4944,6 +4944,20 @@
> this kernel boot parameter, forcibly setting it
> to zero.
>
> + rcutree.rcu_normal_wake_from_gp= [KNL]
> + Reduces a latency of synchronize_rcu() call. This approach
> + maintains its own track of synchronize_rcu() callers, so it
> + does not interact with regular callbacks because it does not
> + use a call_rcu[_hurry]() path. Please note, this is for a
> + normal grace period.
> +
> + How to enable it:
> +
> + echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp
> + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1"
> +
> + Default is 0.
> +
> rcuscale.gp_async= [KNL]
> Measure performance of asynchronous
> grace-period primitives such as call_rcu().
> --
> 2.39.2
>