Update the documentation for the `preempt=' parameter which now also
accepts `lazy'.

Fixes: 7c70cb94d29cd ("sched: Add Lazy preemption model")
Reported-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 Documentation/admin-guide/kernel-parameters.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9cd9cd06538bf..23d9bd5ea7e47 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4818,6 +4818,11 @@
 			       can be preempted anytime.  Tasks will also yield
 			       contended spinlocks (if the critical section isn't
 			       explicitly preempt disabled beyond the lock itself).
+			lazy - Scheduler controlled. Similar to full but instead
+			       of preempting the task immediately, the task gets
+			       one HZ tick time to yield itself before the
+			       preemption will be forced. One preemption is when the
+			       task returns to user space.
 
 	print-fatal-signals=
 			[KNL] debug: print fatal signals
-- 
2.45.2

On 11/22/24 23:05, Sebastian Andrzej Siewior wrote:
> Update the documentation for the `preempt=' parameter which now also
> accepts `lazy'.
> 
> Fixes: 7c70cb94d29cd ("sched: Add Lazy preemption model")
> Reported-by: Shrikanth Hegde <sshegde@linux.ibm.com>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>   Documentation/admin-guide/kernel-parameters.txt | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9cd9cd06538bf..23d9bd5ea7e47 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4818,6 +4818,11 @@
>   			       can be preempted anytime.  Tasks will also yield
>   			       contended spinlocks (if the critical section isn't
>   			       explicitly preempt disabled beyond the lock itself).
> +			lazy - Scheduler controlled. Similar to full but instead
> +			       of preempting the task immediately, the task gets
> +			       one HZ tick time to yield itself before the
> +			       preemption will be forced. One preemption is when the
> +			       task returns to user space.
>   
>   	print-fatal-signals=
>   			[KNL] debug: print fatal signals

Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     f66e4a996582d59b6f5ce88078b0ad2a328aa532
Gitweb:        https://git.kernel.org/tip/f66e4a996582d59b6f5ce88078b0ad2a328aa532
Author:        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate:    Fri, 22 Nov 2024 18:35:57 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 02 Dec 2024 12:01:28 +01:00

sched/core: Update kernel boot parameters for LAZY preempt.

Update the documentation for the `preempt=' parameter which now also
accepts `lazy'.

Fixes: 7c70cb94d29cd ("sched: Add Lazy preemption model")
Reported-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20241122173557.MYOtT95Q@linutronix.de
---
 Documentation/admin-guide/kernel-parameters.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index dc663c0..3872bc6 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4822,6 +4822,11 @@
 			       can be preempted anytime.  Tasks will also yield
 			       contended spinlocks (if the critical section isn't
 			       explicitly preempt disabled beyond the lock itself).
+			lazy - Scheduler controlled. Similar to full but instead
+			       of preempting the task immediately, the task gets
+			       one HZ tick time to yield itself before the
+			       preemption will be forced. One preemption is when the
+			       task returns to user space.
 
 	print-fatal-signals=
 			[KNL] debug: print fatal signals