[PATCH V2 0/8] sched: cleanup trigger_load_balance

[PATCH V2 0/8] sched: cleanup trigger_load_balance

[Daniel Lezcano]

This patchset does a cleanup on the parameters passed from the function
'trigger_load_balance' to the underneath functions.

The cpu is passed as parameter to the different functions as well as the struct
rq but this one contains already the cpu information. Moreover, in the call
stack for these functions, we have the struct rq retrieved from the cpu, and then
the cpu retrieve from the struct rq, etc ...

The patchset unifies all these functions to have a struct rq parameter and
removes the pointless parameters.

-static inline int find_new_ilb(int call_cpu)
+static inline int find_new_ilb(void)

-static void nohz_balancer_kick(int cpu)
+static void nohz_balancer_kick(void)

-static void rebalance_domains(int cpu, enum cpu_idle_type idle)
+static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)

-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)

-static inline int nohz_kick_needed(struct rq *rq, int cpu)
+static inline int nohz_kick_needed(struct rq *rq)

-static inline int on_null_domain(int cpu)
+static inline int on_null_domain(struct rq *rq)

Changelog:

 V2:
	- added missing patch 1/8
	- added acked-by from Preeti U Murthy for patch 4 and 5

Daniel Lezcano (8):
  sched: reduce trigger_load_balance parameters
  sched: reduce nohz_kick_needed parameters
  sched: pass struct rq to on_null_domain function
  sched: remove unused parameter for find_new_ilb
  sched: remove unused parameter in nohz_balancer_kick function
  sched: pass struct rq to rebalance_domains function
  sched: pass struct rq to nohz_idle_balance function
  sched: factor out on_null_domain check in trigger_load_balance
    function

 kernel/sched/core.c  |    2 +-
 kernel/sched/fair.c  |   45 +++++++++++++++++++++++----------------------
 kernel/sched/sched.h |    2 +-
 3 files changed, 25 insertions(+), 24 deletions(-)

-- 
1.7.9.5

[PATCH V2 1/8] sched: reduce trigger_load_balance parameters

[Daniel Lezcano]

The cpu information is already stored in the struct rq, so no need to pass it
as parameter to the trigger_load_balance function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/core.c  |    2 +-
 kernel/sched/fair.c  |    4 +++-
 kernel/sched/sched.h |    2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b21a63e..7007884 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2299,7 +2299,7 @@ void scheduler_tick(void)
 
 #ifdef CONFIG_SMP
 	rq->idle_balance = idle_cpu(cpu);
-	trigger_load_balance(rq, cpu);
+	trigger_load_balance(rq);
 #endif
 	rq_last_tick_reset(rq);
 }
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4316af2..600301c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6869,8 +6869,10 @@ static inline int on_null_domain(int cpu)
 /*
  * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
  */
-void trigger_load_balance(struct rq *rq, int cpu)
+void trigger_load_balance(struct rq *rq)
 {
+	int cpu = rq->cpu;
+
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
 	    likely(!on_null_domain(cpu)))
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b3b4a49..4f10d1a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1052,7 +1052,7 @@ extern const struct sched_class idle_sched_class;
 
 extern void update_group_power(struct sched_domain *sd, int cpu);
 
-extern void trigger_load_balance(struct rq *rq, int cpu);
+extern void trigger_load_balance(struct rq *rq);
 extern void idle_balance(int this_cpu, struct rq *this_rq);
 
 extern void idle_enter_fair(struct rq *this_rq);
-- 
1.7.9.5

[PATCH V2 2/8] sched: reduce nohz_kick_needed parameters

[Daniel Lezcano]

The cpu information is already stored in the struct rq, so no need to pass it
as parameter to the nohz_kick_needed function.

The caller of this function just called idle_cpu() before to fill the
rq->idle_balance field.

Use rq->cpu and rq->idle_balance.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/fair.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 600301c..4cb414a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6781,14 +6781,14 @@ end:
  *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
  *     domain span are idle.
  */
-static inline int nohz_kick_needed(struct rq *rq, int cpu)
+static inline int nohz_kick_needed(struct rq *rq)
 {
 	unsigned long now = jiffies;
 	struct sched_domain *sd;
 	struct sched_group_power *sgp;
-	int nr_busy;
+	int nr_busy, cpu = rq->cpu;
 
-	if (unlikely(idle_cpu(cpu)))
+	if (unlikely(rq->idle_balance))
 		return 0;
 
        /*
@@ -6878,7 +6878,7 @@ void trigger_load_balance(struct rq *rq)
 	    likely(!on_null_domain(cpu)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
+	if (nohz_kick_needed(rq) && likely(!on_null_domain(cpu)))
 		nohz_balancer_kick(cpu);
 #endif
 }
-- 
1.7.9.5

[PATCH V2 3/8] sched: pass struct rq to on_null_domain function

[Daniel Lezcano]

The on_null_domain function is getting the cpu to retrieve the struct rq
associated with it.

Pass the struct rq directly to the function as the caller has already the info.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/fair.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4cb414a..82dd145 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6861,9 +6861,9 @@ static void run_rebalance_domains(struct softirq_action *h)
 	nohz_idle_balance(this_cpu, idle);
 }
 
-static inline int on_null_domain(int cpu)
+static inline int on_null_domain(struct rq *rq)
 {
-	return !rcu_dereference_sched(cpu_rq(cpu)->sd);
+	return !rcu_dereference_sched(rq->sd);
 }
 
 /*
@@ -6875,10 +6875,10 @@ void trigger_load_balance(struct rq *rq)
 
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(cpu)))
+	    likely(!on_null_domain(rq)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq) && likely(!on_null_domain(cpu)))
+	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
 		nohz_balancer_kick(cpu);
 #endif
 }
-- 
1.7.9.5

[PATCH V2 4/8] sched: remove unused parameter for find_new_ilb

[Daniel Lezcano]

The 'call_cpu' is never used in the function. Remove it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
---
 kernel/sched/fair.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 82dd145..1f7ed1a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6502,7 +6502,7 @@ static struct {
 	unsigned long next_balance;     /* in jiffy units */
 } nohz ____cacheline_aligned;
 
-static inline int find_new_ilb(int call_cpu)
+static inline int find_new_ilb(void)
 {
 	int ilb = cpumask_first(nohz.idle_cpus_mask);
 
@@ -6523,7 +6523,7 @@ static void nohz_balancer_kick(int cpu)
 
 	nohz.next_balance++;
 
-	ilb_cpu = find_new_ilb(cpu);
+	ilb_cpu = find_new_ilb();
 
 	if (ilb_cpu >= nr_cpu_ids)
 		return;
-- 
1.7.9.5

[PATCH V2 5/8] sched: remove unused parameter in nohz_balancer_kick function

[Daniel Lezcano]

The cpu parameter is no longer needed in nohz_balancer_kick, let's remove
the parameter.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
---
 kernel/sched/fair.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1f7ed1a..c647c45 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6517,7 +6517,7 @@ static inline int find_new_ilb(void)
  * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle
  * CPU (if there is one).
  */
-static void nohz_balancer_kick(int cpu)
+static void nohz_balancer_kick(void)
 {
 	int ilb_cpu;
 
@@ -6871,15 +6871,13 @@ static inline int on_null_domain(struct rq *rq)
  */
 void trigger_load_balance(struct rq *rq)
 {
-	int cpu = rq->cpu;
-
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
 	    likely(!on_null_domain(rq)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
 	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
-		nohz_balancer_kick(cpu);
+		nohz_balancer_kick();
 #endif
 }
 
-- 
1.7.9.5

[PATCH V2 6/8] sched: pass struct rq to rebalance_domains function

[Daniel Lezcano]

The cpu information is stored in the struct rq and the caller of the
rebalance_domains function pass the cpu to retrieve the struct rq but
it already has the struct rq info. Replace the cpu parameter with the
struct rq.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/fair.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c647c45..0fbd8d0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6633,10 +6633,10 @@ void update_max_interval(void)
  *
  * Balancing parameters are set up in init_sched_domains.
  */
-static void rebalance_domains(int cpu, enum cpu_idle_type idle)
+static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 {
 	int continue_balancing = 1;
-	struct rq *rq = cpu_rq(cpu);
+	int cpu = rq->cpu;
 	unsigned long interval;
 	struct sched_domain *sd;
 	/* Earliest time when we have to do rebalance again */
@@ -6762,7 +6762,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
 		update_idle_cpu_load(rq);
 		raw_spin_unlock_irq(&rq->lock);
 
-		rebalance_domains(balance_cpu, CPU_IDLE);
+		rebalance_domains(rq, CPU_IDLE);
 
 		if (time_after(this_rq->next_balance, rq->next_balance))
 			this_rq->next_balance = rq->next_balance;
@@ -6851,7 +6851,7 @@ static void run_rebalance_domains(struct softirq_action *h)
 	enum cpu_idle_type idle = this_rq->idle_balance ?
 						CPU_IDLE : CPU_NOT_IDLE;
 
-	rebalance_domains(this_cpu, idle);
+	rebalance_domains(this_rq, idle);
 
 	/*
 	 * If this cpu has a pending nohz_balance_kick, then do the
-- 
1.7.9.5

[PATCH V2 7/8] sched: pass struct rq to nohz_idle_balance function

[Daniel Lezcano]

The cpu information is stored in the struct rq. Pass the struct rq to
nohz_idle_balance, so all the functions called in run_rebalance_domains have
the same parameters and the 'this_cpu' variable becomes pointless.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/fair.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0fbd8d0..59c57e7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6733,9 +6733,9 @@ out:
  * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the
  * rebalancing for all the cpus for whom scheduler ticks are stopped.
  */
-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 {
-	struct rq *this_rq = cpu_rq(this_cpu);
+	int this_cpu = this_rq->cpu;
 	struct rq *rq;
 	int balance_cpu;
 
@@ -6846,8 +6846,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
  */
 static void run_rebalance_domains(struct softirq_action *h)
 {
-	int this_cpu = smp_processor_id();
-	struct rq *this_rq = cpu_rq(this_cpu);
+	struct rq *this_rq = this_rq();
 	enum cpu_idle_type idle = this_rq->idle_balance ?
 						CPU_IDLE : CPU_NOT_IDLE;
 
@@ -6858,7 +6857,7 @@ static void run_rebalance_domains(struct softirq_action *h)
 	 * balancing on behalf of the other idle cpus whose ticks are
 	 * stopped.
 	 */
-	nohz_idle_balance(this_cpu, idle);
+	nohz_idle_balance(this_rq, idle);
 }
 
 static inline int on_null_domain(struct rq *rq)
-- 
1.7.9.5

[PATCH V2 8/8] sched: factor out on_null_domain check in trigger_load_balance function

[Daniel Lezcano]

The test on_null_domain is done twice in the trigger_load_balance function.

Move the test at the begin of the function, so there is only one check.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 kernel/sched/fair.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 59c57e7..ef95ddf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6871,11 +6871,13 @@ static inline int on_null_domain(struct rq *rq)
 void trigger_load_balance(struct rq *rq)
 {
 	/* Don't need to rebalance while attached to NULL domain */
-	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(rq)))
+	if (unlikely(on_null_domain(rq)))
+		return;
+
+	if (time_after_eq(jiffies, rq->next_balance))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
+	if (nohz_kick_needed(rq))
 		nohz_balancer_kick();
 #endif
 }
-- 
1.7.9.5

Re: [PATCH V2 0/8] sched: cleanup trigger_load_balance

[Peter Zijlstra]

On Mon, Jan 06, 2014 at 12:34:37PM +0100, Daniel Lezcano wrote:
> This patchset does a cleanup on the parameters passed from the function
> 'trigger_load_balance' to the underneath functions.

Whee.. it applies ;-)

Re: [PATCH V2 0/8] sched: cleanup trigger_load_balance

[Daniel Lezcano]

On 01/06/2014 01:32 PM, Peter Zijlstra wrote:
> On Mon, Jan 06, 2014 at 12:34:37PM +0100, Daniel Lezcano wrote:
>> This patchset does a cleanup on the parameters passed from the function
>> 'trigger_load_balance' to the underneath functions.
>
> Whee.. it applies ;-)

Hi Peter,

do you consider it for upstream ?


Thanks
   -- Daniel

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[tip:sched/core] sched: Reduce trigger_load_balance() parameters

[tip-bot for Daniel Lezcano]

Commit-ID:  7caff66f361c44d0fbc74ed1cfa60a357fc84cf2
Gitweb:     http://git.kernel.org/tip/7caff66f361c44d0fbc74ed1cfa60a357fc84cf2
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:38 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:26 +0100

sched: Reduce trigger_load_balance() parameters

The cpu information is already stored in the struct rq, so no need to pass it
as parameter to the trigger_load_balance function.

Cc: linaro-kernel@lists.linaro.org
Cc: preeti.lkml@gmail.com
Cc: mingo@redhat.com
Cc: peterz@infradead.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-2-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/core.c  | 2 +-
 kernel/sched/fair.c  | 4 +++-
 kernel/sched/sched.h | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a549d9a..392c6f8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2436,7 +2436,7 @@ void scheduler_tick(void)
 
 #ifdef CONFIG_SMP
 	rq->idle_balance = idle_cpu(cpu);
-	trigger_load_balance(rq, cpu);
+	trigger_load_balance(rq);
 #endif
 	rq_last_tick_reset(rq);
 }
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index b73f4ba..b35d322 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6876,8 +6876,10 @@ static inline int on_null_domain(int cpu)
 /*
  * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
  */
-void trigger_load_balance(struct rq *rq, int cpu)
+void trigger_load_balance(struct rq *rq)
 {
+	int cpu = rq->cpu;
+
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
 	    likely(!on_null_domain(cpu)))
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 890339099..c2119fd 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1175,7 +1175,7 @@ extern const struct sched_class idle_sched_class;
 
 extern void update_group_power(struct sched_domain *sd, int cpu);
 
-extern void trigger_load_balance(struct rq *rq, int cpu);
+extern void trigger_load_balance(struct rq *rq);
 extern void idle_balance(int this_cpu, struct rq *this_rq);
 
 extern void idle_enter_fair(struct rq *this_rq);

[tip:sched/core] sched: Reduce nohz_kick_needed() parameters

[tip-bot for Daniel Lezcano]

Commit-ID:  4a725627f21df6b280a19f50bc849daaab3b1544
Gitweb:     http://git.kernel.org/tip/4a725627f21df6b280a19f50bc849daaab3b1544
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:39 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:27 +0100

sched: Reduce nohz_kick_needed() parameters

The cpu information is already stored in the struct rq, so no need to pass it
as parameter to the nohz_kick_needed function.

The caller of this function just called idle_cpu() before to fill the
rq->idle_balance field.

Use rq->cpu and rq->idle_balance.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-3-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index b35d322..c47b1ce 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6788,14 +6788,14 @@ end:
  *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
  *     domain span are idle.
  */
-static inline int nohz_kick_needed(struct rq *rq, int cpu)
+static inline int nohz_kick_needed(struct rq *rq)
 {
 	unsigned long now = jiffies;
 	struct sched_domain *sd;
 	struct sched_group_power *sgp;
-	int nr_busy;
+	int nr_busy, cpu = rq->cpu;
 
-	if (unlikely(idle_cpu(cpu)))
+	if (unlikely(rq->idle_balance))
 		return 0;
 
        /*
@@ -6885,7 +6885,7 @@ void trigger_load_balance(struct rq *rq)
 	    likely(!on_null_domain(cpu)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
+	if (nohz_kick_needed(rq) && likely(!on_null_domain(cpu)))
 		nohz_balancer_kick(cpu);
 #endif
 }

[tip:sched/core] sched: Pass 'struct rq' to on_null_domain()

[tip-bot for Daniel Lezcano]

Commit-ID:  63f609b160151c9e86b26b935c9671a23afe299f
Gitweb:     http://git.kernel.org/tip/63f609b160151c9e86b26b935c9671a23afe299f
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:40 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:28 +0100

sched: Pass 'struct rq' to on_null_domain()

The on_null_domain() function is getting the cpu to retrieve the struct rq
associated with it.

Pass 'struct rq' directly to the function as the caller already has the info.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-4-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c47b1ce..fc0afc5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6868,9 +6868,9 @@ static void run_rebalance_domains(struct softirq_action *h)
 	nohz_idle_balance(this_cpu, idle);
 }
 
-static inline int on_null_domain(int cpu)
+static inline int on_null_domain(struct rq *rq)
 {
-	return !rcu_dereference_sched(cpu_rq(cpu)->sd);
+	return !rcu_dereference_sched(rq->sd);
 }
 
 /*
@@ -6882,10 +6882,10 @@ void trigger_load_balance(struct rq *rq)
 
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(cpu)))
+	    likely(!on_null_domain(rq)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq) && likely(!on_null_domain(cpu)))
+	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
 		nohz_balancer_kick(cpu);
 #endif
 }

[tip:sched/core] sched: Remove unused parameter from find_new_ilb ()

[tip-bot for Daniel Lezcano]

Commit-ID:  3dd0337d6df7d54c82ecebfa6485040f686bf8b1
Gitweb:     http://git.kernel.org/tip/3dd0337d6df7d54c82ecebfa6485040f686bf8b1
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:41 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:29 +0100

sched: Remove unused parameter from find_new_ilb()

The 'call_cpu' is never used in the function. Remove it.

Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-5-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fc0afc5..5fda3c4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6509,7 +6509,7 @@ static struct {
 	unsigned long next_balance;     /* in jiffy units */
 } nohz ____cacheline_aligned;
 
-static inline int find_new_ilb(int call_cpu)
+static inline int find_new_ilb(void)
 {
 	int ilb = cpumask_first(nohz.idle_cpus_mask);
 
@@ -6530,7 +6530,7 @@ static void nohz_balancer_kick(int cpu)
 
 	nohz.next_balance++;
 
-	ilb_cpu = find_new_ilb(cpu);
+	ilb_cpu = find_new_ilb();
 
 	if (ilb_cpu >= nr_cpu_ids)
 		return;

[tip:sched/core] sched: Remove unused parameter from nohz_balancer_kick()

[tip-bot for Daniel Lezcano]

Commit-ID:  0aeeeebac8d8304501680f12862784341f4bee7b
Gitweb:     http://git.kernel.org/tip/0aeeeebac8d8304501680f12862784341f4bee7b
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:42 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:30 +0100

sched: Remove unused parameter from nohz_balancer_kick()

The cpu parameter is no longer needed in nohz_balancer_kick, let's remove
the parameter.

Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-6-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5fda3c4..b91cd93 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6524,7 +6524,7 @@ static inline int find_new_ilb(void)
  * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle
  * CPU (if there is one).
  */
-static void nohz_balancer_kick(int cpu)
+static void nohz_balancer_kick(void)
 {
 	int ilb_cpu;
 
@@ -6878,15 +6878,13 @@ static inline int on_null_domain(struct rq *rq)
  */
 void trigger_load_balance(struct rq *rq)
 {
-	int cpu = rq->cpu;
-
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
 	    likely(!on_null_domain(rq)))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
 	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
-		nohz_balancer_kick(cpu);
+		nohz_balancer_kick();
 #endif
 }
 

[tip:sched/core] sched: Pass 'struct rq' to rebalance_domains()

[tip-bot for Daniel Lezcano]

Commit-ID:  f7ed0a895ead0f093f59898ff9cf4e20768a5f09
Gitweb:     http://git.kernel.org/tip/f7ed0a895ead0f093f59898ff9cf4e20768a5f09
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:43 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:31 +0100

sched: Pass 'struct rq' to rebalance_domains()

The cpu information is stored in the struct rq and the caller of the
rebalance_domains function pass the cpu to retrieve the struct rq but
it already has the struct rq info. Replace the cpu parameter with the
struct rq.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-7-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index b91cd93..ff4e0df 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6640,10 +6640,10 @@ void update_max_interval(void)
  *
  * Balancing parameters are set up in init_sched_domains.
  */
-static void rebalance_domains(int cpu, enum cpu_idle_type idle)
+static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 {
 	int continue_balancing = 1;
-	struct rq *rq = cpu_rq(cpu);
+	int cpu = rq->cpu;
 	unsigned long interval;
 	struct sched_domain *sd;
 	/* Earliest time when we have to do rebalance again */
@@ -6769,7 +6769,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
 		update_idle_cpu_load(rq);
 		raw_spin_unlock_irq(&rq->lock);
 
-		rebalance_domains(balance_cpu, CPU_IDLE);
+		rebalance_domains(rq, CPU_IDLE);
 
 		if (time_after(this_rq->next_balance, rq->next_balance))
 			this_rq->next_balance = rq->next_balance;
@@ -6858,7 +6858,7 @@ static void run_rebalance_domains(struct softirq_action *h)
 	enum cpu_idle_type idle = this_rq->idle_balance ?
 						CPU_IDLE : CPU_NOT_IDLE;
 
-	rebalance_domains(this_cpu, idle);
+	rebalance_domains(this_rq, idle);
 
 	/*
 	 * If this cpu has a pending nohz_balance_kick, then do the

[tip:sched/core] sched: Pass 'struct rq' to nohz_idle_balance()

[tip-bot for Daniel Lezcano]

Commit-ID:  208cb16ba325552a3935bfc002e34561b0d512d7
Gitweb:     http://git.kernel.org/tip/208cb16ba325552a3935bfc002e34561b0d512d7
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:44 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:33 +0100

sched: Pass 'struct rq' to nohz_idle_balance()

The cpu information is stored in the struct rq. Pass the struct rq to
nohz_idle_balance, so all the functions called in run_rebalance_domains have
the same parameters and the 'this_cpu' variable becomes pointless.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ Added !SMP build fix. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-8-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ff4e0df..d7220d1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6740,9 +6740,9 @@ out:
  * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the
  * rebalancing for all the cpus for whom scheduler ticks are stopped.
  */
-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 {
-	struct rq *this_rq = cpu_rq(this_cpu);
+	int this_cpu = this_rq->cpu;
 	struct rq *rq;
 	int balance_cpu;
 
@@ -6844,7 +6844,7 @@ need_kick:
 	return 1;
 }
 #else
-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { }
 #endif
 
 /*
@@ -6853,8 +6853,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
  */
 static void run_rebalance_domains(struct softirq_action *h)
 {
-	int this_cpu = smp_processor_id();
-	struct rq *this_rq = cpu_rq(this_cpu);
+	struct rq *this_rq = this_rq();
 	enum cpu_idle_type idle = this_rq->idle_balance ?
 						CPU_IDLE : CPU_NOT_IDLE;
 
@@ -6865,7 +6864,7 @@ static void run_rebalance_domains(struct softirq_action *h)
 	 * balancing on behalf of the other idle cpus whose ticks are
 	 * stopped.
 	 */
-	nohz_idle_balance(this_cpu, idle);
+	nohz_idle_balance(this_rq, idle);
 }
 
 static inline int on_null_domain(struct rq *rq)

[tip:sched/core] sched: Factor out the on_null_domain() checks in trigger_load_balance()

[tip-bot for Daniel Lezcano]

Commit-ID:  c726099ec224be8078d91072207053ff9a1ad6fc
Gitweb:     http://git.kernel.org/tip/c726099ec224be8078d91072207053ff9a1ad6fc
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:45 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:35 +0100

sched: Factor out the on_null_domain() checks in trigger_load_balance()

The test on_null_domain is done twice in the trigger_load_balance function.

Move the test at the begin of the function, so there is only one check.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-9-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d7220d1..b24b6cf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6878,11 +6878,13 @@ static inline int on_null_domain(struct rq *rq)
 void trigger_load_balance(struct rq *rq)
 {
 	/* Don't need to rebalance while attached to NULL domain */
-	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(rq)))
+	if (unlikely(on_null_domain(rq)))
+		return;
+
+	if (time_after_eq(jiffies, rq->next_balance))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
+	if (nohz_kick_needed(rq))
 		nohz_balancer_kick();
 #endif
 }