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

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index dc663c0ca67067d041cf9a3767117eec765ccca8..3872bc6ec49d63772755504966ae70113f24a1db 100644 (file)
--- 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