From 2bd8e6d422a4f44c0994f909317eba80b0fe08a1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Oct 2007 17:00:02 +0200 Subject: [PATCH] sched: use constants if !CONFIG_SCHED_DEBUG use constants if !CONFIG_SCHED_DEBUG. this speeds up the code and reduces code-size: text data bss dec hex filename 27464 3014 16 30494 771e sched.o.before 26929 3010 20 29959 7507 sched.o.after Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra Signed-off-by: Mike Galbraith Reviewed-by: Thomas Gleixner --- include/linux/sched.h | 5 ++++- kernel/sched.c | 6 ------ kernel/sched_fair.c | 28 ++++++++++++++++++++-------- 3 files changed, 24 insertions(+), 15 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 9761b16..befca3f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1402,15 +1402,18 @@ static inline void idle_task_exit(void) {} extern void sched_idle_next(void); +#ifdef CONFIG_SCHED_DEBUG extern unsigned int sysctl_sched_latency; extern unsigned int sysctl_sched_min_granularity; extern unsigned int sysctl_sched_wakeup_granularity; extern unsigned int sysctl_sched_batch_wakeup_granularity; extern unsigned int sysctl_sched_stat_granularity; extern unsigned int sysctl_sched_runtime_limit; -extern unsigned int sysctl_sched_compat_yield; extern unsigned int sysctl_sched_child_runs_first; extern unsigned int sysctl_sched_features; +#endif + +extern unsigned int sysctl_sched_compat_yield; #ifdef CONFIG_RT_MUTEXES extern int rt_mutex_getprio(struct task_struct *p); diff --git a/kernel/sched.c b/kernel/sched.c index 2520923..ae1544f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1659,12 +1659,6 @@ void sched_fork(struct task_struct *p, int clone_flags) } /* - * After fork, child runs first. (default) If set to 0 then - * parent will (try to) run first. - */ -unsigned int __read_mostly sysctl_sched_child_runs_first = 1; - -/* * wake_up_new_task - wake up a newly created task for the first time. * * This function will do some initial scheduler statistics housekeeping diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 5c15d8a..2e84aaf 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -21,6 +21,15 @@ */ /* + * Tunables that become constants when CONFIG_SCHED_DEBUG is off: + */ +#ifdef CONFIG_SCHED_DEBUG +# define const_debug __read_mostly +#else +# define const_debug static const +#endif + +/* * Targeted preemption latency for CPU-bound tasks: * (default: 20ms, units: nanoseconds) * @@ -34,7 +43,13 @@ * systems, 4x on 8-way systems, 5x on 16-way systems, etc.) * Targeted preemption latency for CPU-bound tasks: */ -unsigned int sysctl_sched_latency __read_mostly = 20000000ULL; +const_debug unsigned int sysctl_sched_latency = 20000000ULL; + +/* + * After fork, child runs first. (default) If set to 0 then + * parent will (try to) run first. + */ +const_debug unsigned int sysctl_sched_child_runs_first = 1; /* * Minimal preemption granularity for CPU-bound tasks: @@ -58,7 +73,7 @@ unsigned int __read_mostly sysctl_sched_compat_yield; * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -unsigned int sysctl_sched_batch_wakeup_granularity __read_mostly = 25000000UL; +const_debug unsigned int sysctl_sched_batch_wakeup_granularity = 25000000UL; /* * SCHED_OTHER wake-up granularity. @@ -68,13 +83,10 @@ unsigned int sysctl_sched_batch_wakeup_granularity __read_mostly = 25000000UL; * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -unsigned int sysctl_sched_wakeup_granularity __read_mostly = 1000000UL; +const_debug unsigned int sysctl_sched_wakeup_granularity = 1000000UL; -unsigned int sysctl_sched_stat_granularity __read_mostly; +const_debug unsigned int sysctl_sched_stat_granularity; -/* - * Initialized in sched_init_granularity() [to 5 times the base granularity]: - */ unsigned int sysctl_sched_runtime_limit __read_mostly; /* @@ -89,7 +101,7 @@ enum { SCHED_FEAT_SKIP_INITIAL = 32, }; -unsigned int sysctl_sched_features __read_mostly = +const_debug unsigned int sysctl_sched_features = SCHED_FEAT_FAIR_SLEEPERS *1 | SCHED_FEAT_SLEEPER_AVG *0 | SCHED_FEAT_SLEEPER_LOAD_AVG *1 | -- 2.7.4