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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2010-09-28 02:25:23 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-11-30 07:01:54 +0100 |
| commit | 24278d148316d2180be6df40e06db013d8b232b8 (patch) | |
| tree | 6a579d483f8f799b352e39b972a7e03cc6204fc1 /init | |
| parent | rcu: move TINY_RCU from softirq to kthread (diff) | |
| download | linux-24278d148316d2180be6df40e06db013d8b232b8.tar.xz linux-24278d148316d2180be6df40e06db013d8b232b8.zip | |
rcu: priority boosting for TINY_PREEMPT_RCU
Add priority boosting, but only for TINY_PREEMPT_RCU. This is enabled
by the default-off RCU_BOOST kernel parameter. The priority to which to
boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel
parameter (defaulting to real-time priority 1) and the time to wait
before boosting the readers blocking a given grace period is controlled
by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds).
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index a619a1ac7f4c..48efefcac12a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -450,6 +450,45 @@ config TREE_RCU_TRACE TREE_PREEMPT_RCU implementations, permitting Makefile to trivially select kernel/rcutree_trace.c. +config RCU_BOOST + bool "Enable RCU priority boosting" + depends on RT_MUTEXES && TINY_PREEMPT_RCU + default n + help + This option boosts the priority of preempted RCU readers that + block the current preemptible RCU grace period for too long. + This option also prevents heavy loads from blocking RCU + callback invocation for all flavors of RCU. + + Say Y here if you are working with real-time apps or heavy loads + Say N here if you are unsure. + +config RCU_BOOST_PRIO + int "Real-time priority to boost RCU readers to" + range 1 99 + depends on RCU_BOOST + default 1 + help + This option specifies the real-time priority to which preempted + RCU readers are to be boosted. If you are working with CPU-bound + real-time applications, you should specify a priority higher then + the highest-priority CPU-bound application. + + Specify the real-time priority, or take the default if unsure. + +config RCU_BOOST_DELAY + int "Milliseconds to delay boosting after RCU grace-period start" + range 0 3000 + depends on RCU_BOOST + default 500 + help + This option specifies the time to wait after the beginning of + a given grace period before priority-boosting preempted RCU + readers blocking that grace period. Note that any RCU reader + blocking an expedited RCU grace period is boosted immediately. + + Accept the default if unsure. + endmenu # "RCU Subsystem" config IKCONFIG |