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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-10-15 17:00:12 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-15 17:00:12 +0200 |
| commit | 5f6d858ecca78f71755859a346d845e302973cd1 (patch) | |
| tree | 5422f6ff9aa7ffab4c708432de84a79e52e503d9 | |
| parent | b0ffd246ea947a037746e725bd461bb7e809a4b3 (diff) | |
| download | linux-5f6d858ecca78f71755859a346d845e302973cd1.tar.gz | |
sched: speed up and simplify vslice calculations
speed up and simplify vslice calculations. [ From: Mike Galbraith <efault@gmx.de>: build fix ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 2 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 15 | ||||
| -rw-r--r-- | kernel/sysctl.c | 9 |
4 files changed, 14 insertions, 14 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index d5daca4bcc6b..97f736b749c2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1400,7 +1400,7 @@ 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_nr_latency; extern unsigned int sysctl_sched_wakeup_granularity; extern unsigned int sysctl_sched_batch_wakeup_granularity; extern unsigned int sysctl_sched_child_runs_first; diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index be79cd6d9e80..995bbd384a97 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -210,7 +210,7 @@ static int sched_debug_show(struct seq_file *m, void *v) #define PN(x) \ SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x)) PN(sysctl_sched_latency); - PN(sysctl_sched_min_granularity); + PN(sysctl_sched_nr_latency); PN(sysctl_sched_wakeup_granularity); PN(sysctl_sched_batch_wakeup_granularity); PN(sysctl_sched_child_runs_first); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ec0569e59e24..ae2d4b08e782 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -46,7 +46,7 @@ const_debug unsigned int sysctl_sched_child_runs_first = 1; * Minimal preemption granularity for CPU-bound tasks: * (default: 2 msec, units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity __read_mostly = 2000000ULL; +const_debug unsigned int sysctl_sched_nr_latency = 20; /* * sys_sched_yield() compat mode @@ -222,8 +222,7 @@ static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) static u64 __sched_period(unsigned long nr_running) { u64 period = sysctl_sched_latency; - unsigned long nr_latency = - sysctl_sched_latency / sysctl_sched_min_granularity; + unsigned long nr_latency = sysctl_sched_nr_latency; if (unlikely(nr_running > nr_latency)) { period *= nr_running; @@ -245,11 +244,15 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) static u64 __sched_vslice(unsigned long nr_running) { - u64 period = __sched_period(nr_running); + unsigned long period = sysctl_sched_latency; + unsigned long nr_latency = sysctl_sched_nr_latency; - do_div(period, nr_running); + if (unlikely(nr_running > nr_latency)) + nr_running = nr_latency; - return period; + period /= nr_running; + + return (u64)period; } /* diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 97b15c27407f..230ca4eb57fe 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -222,14 +222,11 @@ static ctl_table kern_table[] = { #ifdef CONFIG_SCHED_DEBUG { .ctl_name = CTL_UNNUMBERED, - .procname = "sched_min_granularity_ns", - .data = &sysctl_sched_min_granularity, + .procname = "sched_nr_latency", + .data = &sysctl_sched_nr_latency, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, - .extra1 = &min_sched_granularity_ns, - .extra2 = &max_sched_granularity_ns, + .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, |