diff mbox series

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

Message ID 20231128080033.288050-4-urezki@gmail.com
State New
Headers
Series Reduce synchronize_rcu() latency(V3) |

Commit Message

Uladzislau Rezki Nov. 28, 2023, 8 a.m. UTC 
  This commit adds rcutree.rcu_normal_wake_from_gp description
to the kernel-parameters.txt file.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Paul E. McKenney Dec. 20, 2023, 1:17 a.m. UTC | #1 
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@gmail.com>

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
>
Uladzislau Rezki Dec. 21, 2023, 10:28 a.m. UTC | #2 
On Tue, Dec 19, 2023 at 05:17:19PM -0800, Paul E. McKenney wrote:
> 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@gmail.com>
> 
> Very good, but could you please fold this into the first patch, which
> is the one that adds this kernel parameter?
> 
No problem :)

--
Uladzislau Rezki
diff mbox series

Patch

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().