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authorPaul E. McKenney <paulmck@kernel.org>2022-05-11 21:49:35 +0300
committerPaul E. McKenney <paulmck@kernel.org>2022-05-11 21:49:35 +0300
commitce13389053a347aa9f8ffbfda2238352536e15c9 (patch)
tree1bdfa4c0aeb2038dcee1a7802d2d693359e8aeb4 /Documentation/RCU
parentbe05ee54378d451e1d60196921566d6087f3079f (diff)
parent9621fbee44df940e2e1b94b0676460a538dffefa (diff)
downloadlinux-ce13389053a347aa9f8ffbfda2238352536e15c9.tar.xz
Merge branch 'exp.2022.05.11a' into HEAD
exp.2022.05.11a: Expedited-grace-period latency-reduction updates.
Diffstat (limited to 'Documentation/RCU')
-rw-r--r--Documentation/RCU/stallwarn.rst20
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/RCU/stallwarn.rst b/Documentation/RCU/stallwarn.rst
index 78404625bad2..794837eb519b 100644
--- a/Documentation/RCU/stallwarn.rst
+++ b/Documentation/RCU/stallwarn.rst
@@ -162,6 +162,26 @@ CONFIG_RCU_CPU_STALL_TIMEOUT
Stall-warning messages may be enabled and disabled completely via
/sys/module/rcupdate/parameters/rcu_cpu_stall_suppress.
+CONFIG_RCU_EXP_CPU_STALL_TIMEOUT
+--------------------------------
+
+ Same as the CONFIG_RCU_CPU_STALL_TIMEOUT parameter but only for
+ the expedited grace period. This parameter defines the period
+ of time that RCU will wait from the beginning of an expedited
+ grace period until it issues an RCU CPU stall warning. This time
+ period is normally 20 milliseconds on Android devices. A zero
+ value causes the CONFIG_RCU_CPU_STALL_TIMEOUT value to be used,
+ after conversion to milliseconds.
+
+ This configuration parameter may be changed at runtime via the
+ /sys/module/rcupdate/parameters/rcu_exp_cpu_stall_timeout, however
+ this parameter is checked only at the beginning of a cycle. If you
+ are in a current stall cycle, setting it to a new value will change
+ the timeout for the -next- stall.
+
+ Stall-warning messages may be enabled and disabled completely via
+ /sys/module/rcupdate/parameters/rcu_cpu_stall_suppress.
+
RCU_STALL_DELAY_DELTA
---------------------