Re: [PATCH] workqueue: Allocate the unbound pool using local node memory

Re: [PATCH] workqueue: Allocate the unbound pool using local node memory

[Hillf Danton]

> From: Xunlei Pang <pang.xunlei@linaro.org>
> 
> Currently, get_unbound_pool() uses kzalloc() to allocate the
> worker pool. Actually, we can use the right node to do the
> allocation, achieving local memory access.
> 
> This patch selects target node first, and uses kzalloc_node()
> instead.
> 
> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
> ---
>  kernel/workqueue.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index ca71582..96d3747 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -3199,6 +3199,7 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
>  	u32 hash = wqattrs_hash(attrs);
>  	struct worker_pool *pool;
>  	int node;
> +	int target_node = NUMA_NO_NODE;
> 
>  	lockdep_assert_held(&wq_pool_mutex);
> 
> @@ -3210,13 +3211,25 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
>  		}
>  	}
> 
> +	/* if cpumask is contained inside a NUMA node, we belong to that node */
> +	if (wq_numa_enabled) {
> +		for_each_node(node) {
> +			if (cpumask_subset(attrs->cpumask,
> +					   wq_numa_possible_cpumask[node])) {
> +				target_node = node;
> +				break;
> +			}
> +		}
> +	}
> +
>  	/* nope, create a new one */
> -	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
> +	pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, target_node);

What if target_node is short of pages at the moment?

>  	if (!pool || init_worker_pool(pool) < 0)
>  		goto fail;
> 
>  	lockdep_set_subclass(&pool->lock, 1);	/* see put_pwq() */
>  	copy_workqueue_attrs(pool->attrs, attrs);
> +	pool->node = target_node;
> 
>  	/*
>  	 * no_numa isn't a worker_pool attribute, always clear it.  See
> @@ -3224,17 +3237,6 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
>  	 */
>  	pool->attrs->no_numa = false;
> 
> -	/* if cpumask is contained inside a NUMA node, we belong to that node */
> -	if (wq_numa_enabled) {
> -		for_each_node(node) {
> -			if (cpumask_subset(pool->attrs->cpumask,
> -					   wq_numa_possible_cpumask[node])) {
> -				pool->node = node;
> -				break;
> -			}
> -		}
> -	}
> -
>  	if (worker_pool_assign_id(pool) < 0)
>  		goto fail;
> 
> --
> 1.9.1

Re: [PATCH] workqueue: Allocate the unbound pool using local node memory

[pang.xunlei]

Hello,

"Hillf Danton" <hillf.zj@alibaba-inc.com> wrote 2015-10-09 PM 06:05:20:
> 
> Re: [PATCH] workqueue: Allocate the unbound pool using local node memory
> 
> > From: Xunlei Pang <pang.xunlei@linaro.org>
> > 
> > Currently, get_unbound_pool() uses kzalloc() to allocate the
> > worker pool. Actually, we can use the right node to do the
> > allocation, achieving local memory access.
> > 
> > This patch selects target node first, and uses kzalloc_node()
> > instead.
> > 
> > Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
> > ---
> >  kernel/workqueue.c | 26 ++++++++++++++------------
> >  1 file changed, 14 insertions(+), 12 deletions(-)
> > 
> > diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> > index ca71582..96d3747 100644
> > --- a/kernel/workqueue.c
> > +++ b/kernel/workqueue.c
> > @@ -3199,6 +3199,7 @@ static struct worker_pool *get_unbound_pool
> (const struct workqueue_attrs *attrs)
> >     u32 hash = wqattrs_hash(attrs);
> >     struct worker_pool *pool;
> >     int node;
> > +   int target_node = NUMA_NO_NODE;
> > 
> >     lockdep_assert_held(&wq_pool_mutex);
> > 
> > @@ -3210,13 +3211,25 @@ static struct worker_pool 
> *get_unbound_pool(const struct workqueue_attrs *attrs)
> >        }
> >     }
> > 
> > +   /* if cpumask is contained inside a NUMA node, we belong to that 
node */
> > +   if (wq_numa_enabled) {
> > +      for_each_node(node) {
> > +         if (cpumask_subset(attrs->cpumask,
> > +                  wq_numa_possible_cpumask[node])) {
> > +            target_node = node;
> > +            break;
> > +         }
> > +      }
> > +   }
> > +
> >     /* nope, create a new one */
> > -   pool = kzalloc(sizeof(*pool), GFP_KERNEL);
> > +   pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, target_node);
> 
> What if target_node is short of pages at the moment?

IIRC, the zonelist to be used contains all nodes' zones in order 
(otherwise __GFP_THISNODE is set)with target_node's zones having 
the highest priority, so it should automatically fall back to 
other nodes if target_node is short of pages.

Regards,
-Xunlei

> 
> >     if (!pool || init_worker_pool(pool) < 0)
> >        goto fail;
> > 
> >     lockdep_set_subclass(&pool->lock, 1);   /* see put_pwq() */
> >     copy_workqueue_attrs(pool->attrs, attrs);
> > +   pool->node = target_node;
> > 
> >     /*
> >      * no_numa isn't a worker_pool attribute, always clear it.  See
> > @@ -3224,17 +3237,6 @@ static struct worker_pool *get_unbound_pool
> (const struct workqueue_attrs *attrs)
> >      */
> >     pool->attrs->no_numa = false;
> > 
> > -   /* if cpumask is contained inside a NUMA node, we belong to that 
node */
> > -   if (wq_numa_enabled) {
> > -      for_each_node(node) {
> > -         if (cpumask_subset(pool->attrs->cpumask,
> > -                  wq_numa_possible_cpumask[node])) {
> > -            pool->node = node;
> > -            break;
> > -         }
> > -      }
> > -   }
> > -
> >     if (worker_pool_assign_id(pool) < 0)
> >        goto fail;
> > 
> > --
> > 1.9.1
> 

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[PATCH] workqueue: Allocate the unbound pool using local node memory

[Xunlei Pang]

From: Xunlei Pang <pang.xunlei@linaro.org>

Currently, get_unbound_pool() uses kzalloc() to allocate the
worker pool. Actually, we can use the right node to do the
allocation, achieving local memory access.

This patch selects target node first, and uses kzalloc_node()
instead.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
---
 kernel/workqueue.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ca71582..96d3747 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3199,6 +3199,7 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
 	u32 hash = wqattrs_hash(attrs);
 	struct worker_pool *pool;
 	int node;
+	int target_node = NUMA_NO_NODE;
 
 	lockdep_assert_held(&wq_pool_mutex);
 
@@ -3210,13 +3211,25 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
 		}
 	}
 
+	/* if cpumask is contained inside a NUMA node, we belong to that node */
+	if (wq_numa_enabled) {
+		for_each_node(node) {
+			if (cpumask_subset(attrs->cpumask,
+					   wq_numa_possible_cpumask[node])) {
+				target_node = node;
+				break;
+			}
+		}
+	}
+
 	/* nope, create a new one */
-	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, target_node);
 	if (!pool || init_worker_pool(pool) < 0)
 		goto fail;
 
 	lockdep_set_subclass(&pool->lock, 1);	/* see put_pwq() */
 	copy_workqueue_attrs(pool->attrs, attrs);
+	pool->node = target_node;
 
 	/*
 	 * no_numa isn't a worker_pool attribute, always clear it.  See
@@ -3224,17 +3237,6 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
 	 */
 	pool->attrs->no_numa = false;
 
-	/* if cpumask is contained inside a NUMA node, we belong to that node */
-	if (wq_numa_enabled) {
-		for_each_node(node) {
-			if (cpumask_subset(pool->attrs->cpumask,
-					   wq_numa_possible_cpumask[node])) {
-				pool->node = node;
-				break;
-			}
-		}
-	}
-
 	if (worker_pool_assign_id(pool) < 0)
 		goto fail;
 
-- 
1.9.1

Re: [PATCH] workqueue: Allocate the unbound pool using local node memory

[Tejun Heo]

On Fri, Oct 09, 2015 at 11:53:12AM +0800, Xunlei Pang wrote:
> From: Xunlei Pang <pang.xunlei@linaro.org>
> 
> Currently, get_unbound_pool() uses kzalloc() to allocate the
> worker pool. Actually, we can use the right node to do the
> allocation, achieving local memory access.
> 
> This patch selects target node first, and uses kzalloc_node()
> instead.
> 
> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>

Applied to wq/for-4.4.

Thanks.

-- 
tejun