Merge branch 'rcu/doc' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux...

[~andy/linux] / Documentation / kernel-parameters.txt

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8ccbf27aead4def123c94eaf0de40e39db40199f..52ecc9b8467393dce1682e940207187937bc8467 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2484,9 +2484,12 @@ 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.
 
@@ -2510,6 +2513,17 @@ 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.
@@ -2524,16 +2538,15 @@ 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.