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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-05-11 11:49:35 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-05-11 11:49:35 -0700 |
| commit | ce13389053a347aa9f8ffbfda2238352536e15c9 (patch) | |
| tree | 1bdfa4c0aeb2038dcee1a7802d2d693359e8aeb4 /Documentation | |
| parent | be05ee54378d451e1d60196921566d6087f3079f (diff) | |
| parent | 9621fbee44df940e2e1b94b0676460a538dffefa (diff) | |
| download | linux-ce13389053a347aa9f8ffbfda2238352536e15c9.tar.bz2 | |
Merge branch 'exp.2022.05.11a' into HEAD
exp.2022.05.11a: Expedited-grace-period latency-reduction updates.
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/RCU/stallwarn.rst | 20 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 12 |
2 files changed, 32 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 --------------------- diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 82dd253e5dbd..f8d9af5d51e5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4893,6 +4893,18 @@ rcupdate.rcu_cpu_stall_timeout= [KNL] Set timeout for RCU CPU stall warning messages. + The value is in seconds and the maximum allowed + value is 300 seconds. + + rcupdate.rcu_exp_cpu_stall_timeout= [KNL] + Set timeout for expedited RCU CPU stall warning + messages. The value is in milliseconds + and the maximum allowed value is 21000 + milliseconds. Please note that this value is + adjusted to an arch timer tick resolution. + Setting this to zero causes the value from + rcupdate.rcu_cpu_stall_timeout to be used (after + conversion from seconds to milliseconds). rcupdate.rcu_expedited= [KNL] Use expedited grace-period primitives, for |