diff options
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 31 | ||||
| -rw-r--r-- | init/calibrate.c | 13 | ||||
| -rw-r--r-- | init/main.c | 2 |
3 files changed, 34 insertions, 12 deletions
diff --git a/init/Kconfig b/init/Kconfig index a7bcd87ca38..bfa9e13c9a9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -470,6 +470,7 @@ config TREE_RCU config TREE_PREEMPT_RCU bool "Preemptible tree-based hierarchical RCU" depends on PREEMPT + select IRQ_WORK help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -527,13 +528,29 @@ config RCU_USER_QS config CONTEXT_TRACKING_FORCE bool "Force context tracking" depends on CONTEXT_TRACKING - default CONTEXT_TRACKING + default y if !NO_HZ_FULL help - Probe on user/kernel boundaries by default in order to - test the features that rely on it such as userspace RCU extended - quiescent states. - This test is there for debugging until we have a real user like the - full dynticks mode. + The major pre-requirement for full dynticks to work is to + support the context tracking subsystem. But there are also + other dependencies to provide in order to make the full + dynticks working. + + This option stands for testing when an arch implements the + context tracking backend but doesn't yet fullfill all the + requirements to make the full dynticks feature working. + Without the full dynticks, there is no way to test the support + for context tracking and the subsystems that rely on it: RCU + userspace extended quiescent state and tickless cputime + accounting. This option copes with the absence of the full + dynticks subsystem by forcing the context tracking on all + CPUs in the system. + + Say Y only if you're working on the developpement of an + architecture backend for the context tracking. + + Say N otherwise, this option brings an overhead that you + don't want in production. + config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" @@ -955,7 +972,7 @@ config MEMCG_SWAP_ENABLED Memory Resource Controller Swap Extension comes with its price in a bigger memory consumption. General purpose distribution kernels which want to enable the feature but keep it disabled by default - and let the user enable it by swapaccount boot command line + and let the user enable it by swapaccount=1 boot command line parameter should have this option unselected. For those who want to have the feature enabled by default should select this option (if, for some reason, they need to disable it diff --git a/init/calibrate.c b/init/calibrate.c index fda0a7b0f06..520702db9ac 100644 --- a/init/calibrate.c +++ b/init/calibrate.c @@ -31,7 +31,7 @@ __setup("lpj=", lpj_setup); #define DELAY_CALIBRATION_TICKS ((HZ < 100) ? 1 : (HZ/100)) #define MAX_DIRECT_CALIBRATION_RETRIES 5 -static unsigned long __cpuinit calibrate_delay_direct(void) +static unsigned long calibrate_delay_direct(void) { unsigned long pre_start, start, post_start; unsigned long pre_end, end, post_end; @@ -166,7 +166,10 @@ static unsigned long __cpuinit calibrate_delay_direct(void) return 0; } #else -static unsigned long __cpuinit calibrate_delay_direct(void) {return 0;} +static unsigned long calibrate_delay_direct(void) +{ + return 0; +} #endif /* @@ -180,7 +183,7 @@ static unsigned long __cpuinit calibrate_delay_direct(void) {return 0;} */ #define LPS_PREC 8 -static unsigned long __cpuinit calibrate_delay_converge(void) +static unsigned long calibrate_delay_converge(void) { /* First stage - slowly accelerate to find initial bounds */ unsigned long lpj, lpj_base, ticks, loopadd, loopadd_base, chop_limit; @@ -254,12 +257,12 @@ static DEFINE_PER_CPU(unsigned long, cpu_loops_per_jiffy) = { 0 }; * Architectures should override this function if a faster calibration * method is available. */ -unsigned long __attribute__((weak)) __cpuinit calibrate_delay_is_known(void) +unsigned long __attribute__((weak)) calibrate_delay_is_known(void) { return 0; } -void __cpuinit calibrate_delay(void) +void calibrate_delay(void) { unsigned long lpj; static bool printed; diff --git a/init/main.c b/init/main.c index d03d2ec2eac..af310afbef2 100644 --- a/init/main.c +++ b/init/main.c @@ -75,6 +75,7 @@ #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/sched_clock.h> +#include <linux/context_tracking.h> #include <asm/io.h> #include <asm/bugs.h> @@ -545,6 +546,7 @@ asmlinkage void __init start_kernel(void) idr_init_cache(); rcu_init(); tick_nohz_init(); + context_tracking_init(); radix_tree_init(); /* init some links before init_ISA_irqs() */ early_irq_init(); |