1 files changed, 24 insertions, 11 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4609e81dbc37..22303b2e74bc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2461,9 +2461,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         In kernels built with CONFIG_RCU_NOCB_CPU=y, set
                         the specified list of CPUs to be no-callback CPUs.
                         Invocation of these CPUs' RCU callbacks will
-                        be offloaded to "rcuoN" kthreads created for
-                        that purpose.  This reduces OS jitter on the
+                        be offloaded to "rcuox/N" kthreads created for
+                        that purpose, where "x" is "b" for RCU-bh, "p"
+                        for RCU-preempt, and "s" for RCU-sched, and "N"
+                        is the CPU number.  This reduces OS jitter on the
                         offloaded CPUs, which can be useful for HPC and
+
                         real-time workloads.  It can also improve energy
                         efficiency for asymmetric multiprocessors.
 
@@ -2487,6 +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.
@@ -2501,16 +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.