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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-28 19:13:16 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-28 19:13:16 +0100 |
| commit | 642c4c75a765d7a3244ab39c8e6fb09be21eca5b (patch) | |
| tree | ce0be9b476f362835d3a3d6e4fd32801cd15c9fe /init | |
| parent | Merge branches 'core-ipi-for-linus', 'core-locking-for-linus', 'tracing-fixes... (diff) | |
| parent | rcu: Fix accelerated GPs for last non-dynticked CPU (diff) | |
| download | linux-642c4c75a765d7a3244ab39c8e6fb09be21eca5b.tar.xz linux-642c4c75a765d7a3244ab39c8e6fb09be21eca5b.zip | |
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (44 commits)
rcu: Fix accelerated GPs for last non-dynticked CPU
rcu: Make non-RCU_PROVE_LOCKING rcu_read_lock_sched_held() understand boot
rcu: Fix accelerated grace periods for last non-dynticked CPU
rcu: Export rcu_scheduler_active
rcu: Make rcu_read_lock_sched_held() take boot time into account
rcu: Make lockdep_rcu_dereference() message less alarmist
sched, cgroups: Fix module export
rcu: Add RCU_CPU_STALL_VERBOSE to dump detailed per-task information
rcu: Fix rcutorture mod_timer argument to delay one jiffy
rcu: Fix deadlock in TREE_PREEMPT_RCU CPU stall detection
rcu: Convert to raw_spinlocks
rcu: Stop overflowing signed integers
rcu: Use canonical URL for Mathieu's dissertation
rcu: Accelerate grace period if last non-dynticked CPU
rcu: Fix citation of Mathieu's dissertation
rcu: Documentation update for CONFIG_PROVE_RCU
security: Apply lockdep-based checking to rcu_dereference() uses
idr: Apply lockdep-based diagnostics to rcu_dereference() uses
radix-tree: Disable RCU lockdep checking in radix tree
vfs: Abstract rcu_dereference_check for files-fdtable use
...
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 16 | ||||
| -rw-r--r-- | init/main.c | 2 |
2 files changed, 18 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index 1510e17a2902..d038a57004a2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -396,6 +396,22 @@ config RCU_FANOUT_EXACT Say N if unsure. +config RCU_FAST_NO_HZ + bool "Accelerate last non-dyntick-idle CPU's grace periods" + depends on TREE_RCU && NO_HZ && SMP + default n + help + This option causes RCU to attempt to accelerate grace periods + in order to allow the final CPU to enter dynticks-idle state + more quickly. On the other hand, this option increases the + overhead of the dynticks-idle checking, particularly on systems + with large numbers of CPUs. + + Say Y if energy efficiency is critically important, particularly + if you have relatively few CPUs. + + Say N if you are unsure. + config TREE_RCU_TRACE def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU ) select DEBUG_FS diff --git a/init/main.c b/init/main.c index 4cb47a159f02..c75dcd6eef09 100644 --- a/init/main.c +++ b/init/main.c @@ -416,7 +416,9 @@ static noinline void __init_refok rest_init(void) kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); numa_default_policy(); pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); + rcu_read_lock(); kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); + rcu_read_unlock(); unlock_kernel(); /* |