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* [PATCH] sched/isolation: Prefer housekeeping cpu in local node
@ 2019-06-20 11:36 Wanpeng Li
  2019-06-20 12:38 ` Peter Zijlstra
  0 siblings, 1 reply; 3+ messages in thread
From: Wanpeng Li @ 2019-06-20 11:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: Ingo Molnar, Peter Zijlstra, Ingo Molnar, Frederic Weisbecker

From: Wanpeng Li <wanpengli@tencent.com>

In real product setup, there will be houseeking cpus in each nodes, it 
is prefer to do housekeeping from local node, fallback to global online 
cpumask if failed to find houseeking cpu from local node.

Cc: Ingo Molnar <mingo@redhat.com> 
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 kernel/sched/isolation.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 123ea07..9eb6805 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -16,9 +16,16 @@ static unsigned int housekeeping_flags;
 
 int housekeeping_any_cpu(enum hk_flags flags)
 {
+	int cpu;
+
 	if (static_branch_unlikely(&housekeeping_overridden))
-		if (housekeeping_flags & flags)
-			return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+		if (housekeeping_flags & flags) {
+			cpu = cpumask_any_and(housekeeping_mask, cpu_cpu_mask(smp_processor_id()));
+			if (cpu < nr_cpu_ids)
+				return cpu;
+			else
+				return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+		}
 	return smp_processor_id();
 }
 EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
-- 
2.7.4


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] sched/isolation: Prefer housekeeping cpu in local node
  2019-06-20 11:36 [PATCH] sched/isolation: Prefer housekeeping cpu in local node Wanpeng Li
@ 2019-06-20 12:38 ` Peter Zijlstra
  2019-06-21  1:36   ` Wanpeng Li
  0 siblings, 1 reply; 3+ messages in thread
From: Peter Zijlstra @ 2019-06-20 12:38 UTC (permalink / raw)
  To: Wanpeng Li; +Cc: linux-kernel, Ingo Molnar, Ingo Molnar, Frederic Weisbecker

On Thu, Jun 20, 2019 at 07:36:54PM +0800, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@tencent.com>
> 
> In real product setup, there will be houseeking cpus in each nodes, it 
> is prefer to do housekeeping from local node, fallback to global online 
> cpumask if failed to find houseeking cpu from local node.
> 
> Cc: Ingo Molnar <mingo@redhat.com> 
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Frederic Weisbecker <frederic@kernel.org>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
>  kernel/sched/isolation.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
> index 123ea07..9eb6805 100644
> --- a/kernel/sched/isolation.c
> +++ b/kernel/sched/isolation.c
> @@ -16,9 +16,16 @@ static unsigned int housekeeping_flags;
>  
>  int housekeeping_any_cpu(enum hk_flags flags)
>  {
> +	int cpu;
> +
>  	if (static_branch_unlikely(&housekeeping_overridden))
> -		if (housekeeping_flags & flags)
> -			return cpumask_any_and(housekeeping_mask, cpu_online_mask);
> +		if (housekeeping_flags & flags) {
> +			cpu = cpumask_any_and(housekeeping_mask, cpu_cpu_mask(smp_processor_id()));
> +			if (cpu < nr_cpu_ids)
> +				return cpu;
> +			else
> +				return cpumask_any_and(housekeeping_mask, cpu_online_mask);
> +		}
>  	return smp_processor_id();
>  }
>  EXPORT_SYMBOL_GPL(housekeeping_any_cpu);

Why not something like so? IIRC there's more places that want this, but
I can't seem to remember quite where.

diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 123ea07a3f3b..1cceab5f094c 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -16,9 +16,15 @@ static unsigned int housekeeping_flags;
 
 int housekeeping_any_cpu(enum hk_flags flags)
 {
-	if (static_branch_unlikely(&housekeeping_overridden))
-		if (housekeeping_flags & flags)
+	if (static_branch_unlikely(&housekeeping_overridden)) {
+		if (housekeeping_flags & flags) {
+			cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id());
+			if (cpu < nr_cpu_ids)
+				return cpu;
+
 			return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+		}
+	}
 	return smp_processor_id();
 }
 EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b08dee29ef5e..0db7431c7207 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1212,9 +1212,6 @@ enum numa_topology_type {
 extern enum numa_topology_type sched_numa_topology_type;
 extern int sched_max_numa_distance;
 extern bool find_numa_distance(int distance);
-#endif
-
-#ifdef CONFIG_NUMA
 extern void sched_init_numa(void);
 extern void sched_domains_numa_masks_set(unsigned int cpu);
 extern void sched_domains_numa_masks_clear(unsigned int cpu);
@@ -1224,6 +1221,8 @@ static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
 #endif
 
+extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
+
 #ifdef CONFIG_NUMA_BALANCING
 /* The regions in numa_faults array from task_struct */
 enum numa_faults_stats {
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 63184cf0d0d7..408e94a6637c 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1726,6 +1726,20 @@ void sched_domains_numa_masks_clear(unsigned int cpu)
 
 #endif /* CONFIG_NUMA */
 
+int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
+{
+#ifdef CONFIG_NUMA
+	int i, j = cpu_to_node(cpu);
+
+	for (i = 0; i < sched_domains_numa_levels; ++) {
+		cpu = cpumask_any_and(cpus, sched_domains_numa_mask[i][j]);
+		if (cpu < nr_cpu_ids)
+			return cpu;
+	}
+#endif
+	return nr_cpu_ids;
+}
+
 static int __sdt_alloc(const struct cpumask *cpu_map)
 {
 	struct sched_domain_topology_level *tl;

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] sched/isolation: Prefer housekeeping cpu in local node
  2019-06-20 12:38 ` Peter Zijlstra
@ 2019-06-21  1:36   ` Wanpeng Li
  0 siblings, 0 replies; 3+ messages in thread
From: Wanpeng Li @ 2019-06-21  1:36 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: LKML, Ingo Molnar, Ingo Molnar, Frederic Weisbecker

On Thu, 20 Jun 2019 at 20:38, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Thu, Jun 20, 2019 at 07:36:54PM +0800, Wanpeng Li wrote:
> > From: Wanpeng Li <wanpengli@tencent.com>
> >
> > In real product setup, there will be houseeking cpus in each nodes, it
> > is prefer to do housekeeping from local node, fallback to global online
> > cpumask if failed to find houseeking cpu from local node.
> >
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Frederic Weisbecker <frederic@kernel.org>
> > Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> > ---
> >  kernel/sched/isolation.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
> > index 123ea07..9eb6805 100644
> > --- a/kernel/sched/isolation.c
> > +++ b/kernel/sched/isolation.c
> > @@ -16,9 +16,16 @@ static unsigned int housekeeping_flags;
> >
> >  int housekeeping_any_cpu(enum hk_flags flags)
> >  {
> > +     int cpu;
> > +
> >       if (static_branch_unlikely(&housekeeping_overridden))
> > -             if (housekeeping_flags & flags)
> > -                     return cpumask_any_and(housekeeping_mask, cpu_online_mask);
> > +             if (housekeeping_flags & flags) {
> > +                     cpu = cpumask_any_and(housekeeping_mask, cpu_cpu_mask(smp_processor_id()));
> > +                     if (cpu < nr_cpu_ids)
> > +                             return cpu;
> > +                     else
> > +                             return cpumask_any_and(housekeeping_mask, cpu_online_mask);
> > +             }
> >       return smp_processor_id();
> >  }
> >  EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
>
> Why not something like so? IIRC there's more places that want this, but
> I can't seem to remember quite where.

Good point, do it in v2. Btw, could you have a look this patch?
https://lkml.org/lkml/2019/6/17/1723

Regards,
Wanpeng Li

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-06-21  1:41 UTC | newest]

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2019-06-20 11:36 [PATCH] sched/isolation: Prefer housekeeping cpu in local node Wanpeng Li
2019-06-20 12:38 ` Peter Zijlstra
2019-06-21  1:36   ` Wanpeng Li

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