diff options
Diffstat (limited to 'init/Kconfig')
| -rw-r--r-- | init/Kconfig | 49 |
1 files changed, 21 insertions, 28 deletions
diff --git a/init/Kconfig b/init/Kconfig index 3ee28ae02cc8..5ac596e2cb4b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -477,7 +477,7 @@ config TREE_RCU thousands of CPUs. It also scales down nicely to smaller systems. -config TREE_PREEMPT_RCU +config PREEMPT_RCU bool "Preemptible tree-based hierarchical RCU" depends on PREEMPT select IRQ_WORK @@ -501,12 +501,6 @@ config TINY_RCU endchoice -config PREEMPT_RCU - def_bool TREE_PREEMPT_RCU - help - This option enables preemptible-RCU code that is common between - TREE_PREEMPT_RCU and, in the old days, TINY_PREEMPT_RCU. - config TASKS_RCU bool "Task_based RCU implementation using voluntary context switch" default n @@ -518,7 +512,7 @@ config TASKS_RCU If unsure, say N. config RCU_STALL_COMMON - def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE ) + def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE ) help This option enables RCU CPU stall code that is common between the TINY and TREE variants of RCU. The purpose is to allow @@ -576,7 +570,7 @@ config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" range 2 64 if 64BIT range 2 32 if !64BIT - depends on TREE_RCU || TREE_PREEMPT_RCU + depends on TREE_RCU || PREEMPT_RCU default 64 if 64BIT default 32 if !64BIT help @@ -596,7 +590,7 @@ 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 || TREE_PREEMPT_RCU + depends on TREE_RCU || PREEMPT_RCU default 16 help This option controls the leaf-level fanout of hierarchical @@ -621,7 +615,7 @@ config RCU_FANOUT_LEAF config RCU_FANOUT_EXACT bool "Disable tree-based hierarchical RCU auto-balancing" - depends on TREE_RCU || TREE_PREEMPT_RCU + depends on TREE_RCU || PREEMPT_RCU default n help This option forces use of the exact RCU_FANOUT value specified, @@ -652,11 +646,11 @@ config RCU_FAST_NO_HZ Say N if you are unsure. config TREE_RCU_TRACE - def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU ) + def_bool RCU_TRACE && ( TREE_RCU || PREEMPT_RCU ) select DEBUG_FS help This option provides tracing for the TREE_RCU and - TREE_PREEMPT_RCU implementations, permitting Makefile to + PREEMPT_RCU implementations, permitting Makefile to trivially select kernel/rcutree_trace.c. config RCU_BOOST @@ -672,30 +666,31 @@ config RCU_BOOST 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" +config RCU_KTHREAD_PRIO + int "Real-time priority to use for RCU worker threads" range 1 99 depends on RCU_BOOST default 1 help - This option specifies the real-time priority to which long-term - preempted RCU readers are to be boosted. If you are working - with a real-time application that has one or more CPU-bound - threads running at a real-time priority level, you should set - RCU_BOOST_PRIO to a priority higher then the highest-priority - real-time CPU-bound thread. The default RCU_BOOST_PRIO value - of 1 is appropriate in the common case, which is real-time + 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 + used for RCU_BOOST (if enabled). If you are working with a + real-time application that has one or more CPU-bound threads + running at a real-time priority level, you should set + RCU_KTHREAD_PRIO to a priority higher than the highest-priority + real-time CPU-bound application thread. The default RCU_KTHREAD_PRIO + value of 1 is appropriate in the common case, which is real-time applications that do not have any CPU-bound threads. Some real-time applications might not have a single real-time thread that saturates a given CPU, but instead might have multiple real-time threads that, taken together, fully utilize - that CPU. In this case, you should set RCU_BOOST_PRIO to + that CPU. In this case, you should set RCU_KTHREAD_PRIO to a priority higher than the lowest-priority thread that is conspiring to prevent the CPU from running any non-real-time tasks. For example, if one thread at priority 10 and another thread at priority 5 are between themselves fully consuming - the CPU time on a given CPU, then RCU_BOOST_PRIO should be + the CPU time on a given CPU, then RCU_KTHREAD_PRIO should be set to priority 6 or higher. Specify the real-time priority, or take the default if unsure. @@ -715,7 +710,7 @@ config RCU_BOOST_DELAY config RCU_NOCB_CPU bool "Offload RCU callback processing from boot-selected CPUs" - depends on TREE_RCU || TREE_PREEMPT_RCU + depends on TREE_RCU || PREEMPT_RCU default n help Use this option to reduce OS jitter for aggressive HPC or @@ -739,6 +734,7 @@ config RCU_NOCB_CPU choice prompt "Build-forced no-CBs CPUs" default RCU_NOCB_CPU_NONE + depends on RCU_NOCB_CPU help This option allows no-CBs CPUs (whose RCU callbacks are invoked from kthreads rather than from softirq context) to be specified @@ -747,7 +743,6 @@ choice config RCU_NOCB_CPU_NONE bool "No build_forced no-CBs CPUs" - depends on RCU_NOCB_CPU help This option does not force any of the CPUs to be no-CBs CPUs. Only CPUs designated by the rcu_nocbs= boot parameter will be @@ -761,7 +756,6 @@ config RCU_NOCB_CPU_NONE config RCU_NOCB_CPU_ZERO bool "CPU 0 is a build_forced no-CBs CPU" - depends on RCU_NOCB_CPU help This option forces CPU 0 to be a no-CBs CPU, so that its RCU callbacks are invoked by a per-CPU kthread whose name begins @@ -776,7 +770,6 @@ config RCU_NOCB_CPU_ZERO config RCU_NOCB_CPU_ALL bool "All CPUs are build_forced no-CBs CPUs" - depends on RCU_NOCB_CPU help This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs= boot parameter will be ignored. All CPUs' RCU callbacks will |