rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks

[mirror_ubuntu-eoan-kernel.git] / Documentation / kernel-parameters.txt

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a17ba16c8fc8e3977760d614833a0e24636c2aa5..22303b2e74bc9def14d48d27889b9d58769490dd 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2490,6 +2490,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        leaf rcu_node structure.  Useful for very large
                        systems.
 
+       rcutree.jiffies_till_first_fqs= [KNL,BOOT]
+                       Set delay from grace-period initialization to
+                       first attempt to force quiescent states.
+                       Units are jiffies, minimum value is zero,
+                       and maximum value is HZ.
+
+       rcutree.jiffies_till_next_fqs= [KNL,BOOT]
+                       Set delay between subsequent attempts to force
+                       quiescent states.  Units are jiffies, minimum
+                       value is one, and maximum value is HZ.
+
        rcutree.qhimark=        [KNL,BOOT]
                        Set threshold of queued
                        RCU callbacks over which batch limiting is disabled.
@@ -2504,16 +2515,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
        rcutree.rcu_cpu_stall_timeout= [KNL,BOOT]
                        Set timeout for RCU CPU stall warning messages.
 
-       rcutree.jiffies_till_first_fqs= [KNL,BOOT]
-                       Set delay from grace-period initialization to
-                       first attempt to force quiescent states.
-                       Units are jiffies, minimum value is zero,
-                       and maximum value is HZ.
+       rcutree.rcu_idle_gp_delay=      [KNL,BOOT]
+                       Set wakeup interval for idle CPUs that have
+                       RCU callbacks (RCU_FAST_NO_HZ=y).
 
-       rcutree.jiffies_till_next_fqs= [KNL,BOOT]
-                       Set delay between subsequent attempts to force
-                       quiescent states.  Units are jiffies, minimum
-                       value is one, and maximum value is HZ.
+       rcutree.rcu_idle_lazy_gp_delay= [KNL,BOOT]
+                       Set wakeup interval for idle CPUs that have
+                       only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
+                       Lazy RCU callbacks are those which RCU can
+                       prove do nothing more than free memory.
 
        rcutorture.fqs_duration= [KNL,BOOT]
                        Set duration of force_quiescent_state bursts.