diff options
Diffstat (limited to 'init/Kconfig')
| -rw-r--r-- | init/Kconfig | 72 |
1 files changed, 29 insertions, 43 deletions
diff --git a/init/Kconfig b/init/Kconfig index dc24dec60232..4c08197044f1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -465,13 +465,9 @@ endmenu # "CPU/Task time and stats accounting" menu "RCU Subsystem" -choice - prompt "RCU Implementation" - default TREE_RCU - config TREE_RCU - bool "Tree-based hierarchical RCU" - depends on !PREEMPT && SMP + bool + default y if !PREEMPT && SMP help This option selects the RCU implementation that is designed for very large SMP system with hundreds or @@ -479,8 +475,8 @@ config TREE_RCU smaller systems. config PREEMPT_RCU - bool "Preemptible tree-based hierarchical RCU" - depends on PREEMPT + bool + default y if PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -491,15 +487,28 @@ config PREEMPT_RCU Select this option if you are unsure. config TINY_RCU - bool "UP-only small-memory-footprint RCU" - depends on !PREEMPT && !SMP + bool + default y if !PREEMPT && !SMP help This option selects the RCU implementation that is designed for UP systems from which real-time response is not required. This option greatly reduces the memory footprint of RCU. -endchoice +config RCU_EXPERT + bool "Make expert-level adjustments to RCU configuration" + default n + help + This option needs to be enabled if you wish to make + expert-level adjustments to RCU configuration. By default, + no such adjustments can be made, which has the often-beneficial + side-effect of preventing "make oldconfig" from asking you all + sorts of detailed questions about how you would like numerous + obscure RCU options to be set up. + + Say Y if you need to make expert-level adjustments to RCU. + + Say N if you are unsure. config SRCU bool @@ -509,7 +518,7 @@ config SRCU sections. config TASKS_RCU - bool "Task_based RCU implementation using voluntary context switch" + bool default n select SRCU help @@ -517,8 +526,6 @@ config TASKS_RCU only voluntary context switch (not preemption!), idle, and user-mode execution as quiescent states. - If unsure, say N. - config RCU_STALL_COMMON def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE ) help @@ -531,9 +538,7 @@ config CONTEXT_TRACKING bool config RCU_USER_QS - bool "Consider userspace as in RCU extended quiescent state" - depends on HAVE_CONTEXT_TRACKING && SMP - select CONTEXT_TRACKING + bool help This option sets hooks on kernel / userspace boundaries and puts RCU in extended quiescent state when the CPU runs in @@ -541,12 +546,6 @@ config RCU_USER_QS excluded from the global RCU state machine and thus doesn't try to keep the timer tick on for RCU. - Unless you want to hack and help the development of the full - dynticks mode, you shouldn't enable this option. It also - adds unnecessary overhead. - - If unsure say N - config CONTEXT_TRACKING_FORCE bool "Force context tracking" depends on CONTEXT_TRACKING @@ -578,7 +577,7 @@ config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" range 2 64 if 64BIT range 2 32 if !64BIT - depends on TREE_RCU || PREEMPT_RCU + depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT default 64 if 64BIT default 32 if !64BIT help @@ -596,9 +595,9 @@ config RCU_FANOUT config RCU_FANOUT_LEAF int "Tree-based hierarchical RCU leaf-level fanout value" - range 2 RCU_FANOUT if 64BIT - range 2 RCU_FANOUT if !64BIT - depends on TREE_RCU || PREEMPT_RCU + range 2 64 if 64BIT + range 2 32 if !64BIT + depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT default 16 help This option controls the leaf-level fanout of hierarchical @@ -621,23 +620,9 @@ config RCU_FANOUT_LEAF Take the default if unsure. -config RCU_FANOUT_EXACT - bool "Disable tree-based hierarchical RCU auto-balancing" - depends on TREE_RCU || PREEMPT_RCU - default n - help - This option forces use of the exact RCU_FANOUT value specified, - regardless of imbalances in the hierarchy. This is useful for - testing RCU itself, and might one day be useful on systems with - strong NUMA behavior. - - Without RCU_FANOUT_EXACT, the code will balance the hierarchy. - - Say N if unsure. - config RCU_FAST_NO_HZ bool "Accelerate last non-dyntick-idle CPU's grace periods" - depends on NO_HZ_COMMON && SMP + depends on NO_HZ_COMMON && SMP && RCU_EXPERT default n help This option permits CPUs to enter dynticks-idle state even if @@ -663,7 +648,7 @@ config TREE_RCU_TRACE config RCU_BOOST bool "Enable RCU priority boosting" - depends on RT_MUTEXES && PREEMPT_RCU + depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT default n help This option boosts the priority of preempted RCU readers that @@ -680,6 +665,7 @@ config RCU_KTHREAD_PRIO range 0 99 if !RCU_BOOST default 1 if RCU_BOOST default 0 if !RCU_BOOST + depends on RCU_EXPERT help This option specifies the SCHED_FIFO priority value that will be assigned to the rcuc/n and rcub/n threads and is also the value |