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 <[email protected]>
---
kernel/sched/core.c | 3 ---
kernel/sched/rt.c | 40 ----------------------------------------
kernel/sched/sched.h | 1 -
3 files changed, 0 insertions(+), 44 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7f12624..3719c3c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6831,9 +6831,6 @@ 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 */
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 127a2c4..111539a 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -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;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index cc03cfd..e73a8bd 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -892,7 +892,6 @@ extern void sysrq_sched_debug_show(void);
extern void sched_init_granularity(void);
extern void update_max_interval(void);
extern void update_group_power(struct sched_domain *sd, int cpu);
-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);
--
1.7.4.1
On Thu, Apr 11, 2013 at 09:04:59PM +0800, Neil Zhang wrote:
> 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.
>
Indeed, it looks like the 'new' sched_class::rq_{on,off}line stuff handles all
that just fine.
Thanks for spotting that.
Commit-ID: c5405a495e88d93cf9b4f4cc91507c7f4afcb901
Gitweb: http://git.kernel.org/tip/c5405a495e88d93cf9b4f4cc91507c7f4afcb901
Author: Neil Zhang <[email protected]>
AuthorDate: Thu, 11 Apr 2013 21:04:59 +0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Tue, 28 May 2013 09:40:22 +0200
sched: Remove redundant update_runtime notifier
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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/sched/core.c | 3 ---
kernel/sched/rt.c | 40 ----------------------------------------
kernel/sched/sched.h | 1 -
3 files changed, 44 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index bfa7e77..79e48e6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -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 */
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 7aced2e..8853ab1 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -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;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f1f6256..c806c61 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -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);