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sched: Remove redundant update_runtime notifier

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migration_call() will do all the things that update_runtime() does.
So let's remove it.

Furthermore, there is potential risk that the current code will catch
BUG_ON at line 689 of rt.c when do cpu hotplug while there are realtime
threads running because of enabling runtime twice while the rt_runtime
may already changed.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365685499-26515-1-git-send-email-zhangwm@marvell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Neil Zhang 2013-04-11 21:04:59 +08:00 committed by Ingo Molnar
parent 41261b6a83
commit c5405a495e
3 changed files with 0 additions and 44 deletions
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3
kernel/sched/core.c
View file

@ -6285,9 +6285,6 @@ void __init sched_init_smp(void)
hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
/* RT runtime code needs to handle some hotplug events */
hotcpu_notifier(update_runtime, 0);
init_hrtick();
/* Move init over to a non-isolated CPU */

40
kernel/sched/rt.c
View file

@ -699,15 +699,6 @@ balanced:
}
}
static void disable_runtime(struct rq *rq)
{
unsigned long flags;
raw_spin_lock_irqsave(&rq->lock, flags);
__disable_runtime(rq);
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
static void __enable_runtime(struct rq *rq)
{
rt_rq_iter_t iter;
@ -732,37 +723,6 @@ static void __enable_runtime(struct rq *rq)
}
}
static void enable_runtime(struct rq *rq)
{
unsigned long flags;
raw_spin_lock_irqsave(&rq->lock, flags);
__enable_runtime(rq);
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
int cpu = (int)(long)hcpu;
switch (action) {
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
disable_runtime(cpu_rq(cpu));
return NOTIFY_OK;
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
enable_runtime(cpu_rq(cpu));
return NOTIFY_OK;
default:
return NOTIFY_DONE;
}
}
static int balance_runtime(struct rt_rq *rt_rq)
{
int more = 0;

1
kernel/sched/sched.h
View file

@ -1041,7 +1041,6 @@ static inline void idle_balance(int cpu, struct rq *rq)
extern void sysrq_sched_debug_show(void);
extern void sched_init_granularity(void);
extern void update_max_interval(void);
extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu);
extern void init_sched_rt_class(void);
extern void init_sched_fair_class(void);