Make the descriptions of CONFIG_EXT_RCU_CPU_STALL_TIMEOUT
match the code:
- there is no longer a default of 20 ms for Android since
commit 1045a06724f3 ("remove CONFIG_ANDROID"),
- the code includes a maximum of 21 seconds, evident when
specifying 0 which means to use the CONFIG_RCU_STALL_TIMEOUT
value (whose default is 60 seconds).
Example .config:
CONFIG_RCU_CPU_STALL_TIMEOUT=60
CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=0
leads to:
/sys/module/rcupdate/parameters/rcu_cpu_stall_timeout:60
/sys/module/rcupdate/parameters/rcu_exp_cpu_stall_timeout:21000
Fixes: 1045a06724f3 ("remove CONFIG_ANDROID")
Signed-off-by: Robert Elliott <elliott@xxxxxxx>
---
Documentation/RCU/stallwarn.rst | 9 +++++----
kernel/rcu/Kconfig.debug | 2 +-
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/Documentation/RCU/stallwarn.rst b/Documentation/RCU/stallwarn.rst
index e38c587067fc..d86a8b47504f 100644
--- a/Documentation/RCU/stallwarn.rst
+++ b/Documentation/RCU/stallwarn.rst
@@ -168,10 +168,11 @@ 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.
+ grace period until it issues an RCU CPU stall warning.
+
+ A zero value causes the CONFIG_RCU_CPU_STALL_TIMEOUT value to be
+ used, after conversion to milliseconds, limited to a maximum of
+ 21 seconds.
This configuration parameter may be changed at runtime via the
/sys/module/rcupdate/parameters/rcu_exp_cpu_stall_timeout, however
diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 1b0c41d490f0..4477eeb8a54f 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -93,7 +93,7 @@ config RCU_EXP_CPU_STALL_TIMEOUT
If the RCU grace period persists, additional CPU stall warnings
are printed at more widely spaced intervals. A value of zero
says to use the RCU_CPU_STALL_TIMEOUT value converted from
- seconds to milliseconds.
+ seconds to milliseconds, limited to a maximum of 21 seconds.
config RCU_TRACE
bool "Enable tracing for RCU"
--
2.37.3
