[PATCH 11/17] mm: move get_dev_pagemap out of line
This is a pretty big function, which should be out of line in general,
and a no-op stub if CONFIG_ZONE_DEVICЕ is not set.
Signed-off-by: Christoph Hellwig
Reviewed-by: Logan Gunthorpe
Reviewed-by: Dan Williams
---
include/linux/memremap.h | 39 ---
kernel/memremap.c| 36 ++--
2 files changed, 38 insertions(+), 37 deletions(-)
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index d5a6736d9737..26e8aaba27d5 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -133,7 +133,8 @@ struct dev_pagemap {
#ifdef CONFIG_ZONE_DEVICE
void *devm_memremap_pages(struct device *dev, struct resource *res,
struct percpu_ref *ref, struct vmem_altmap *altmap);
-struct dev_pagemap *find_dev_pagemap(resource_size_t phys);
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap);
unsigned long vmem_altmap_offset(struct vmem_altmap *altmap);
void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns);
@@ -153,7 +154,8 @@ static inline void *devm_memremap_pages(struct device *dev,
return ERR_PTR(-ENXIO);
}
-static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap)
{
return NULL;
}
@@ -183,39 +185,6 @@ static inline bool is_device_public_page(const struct page
*page)
}
#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
-/**
- * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
- * @pfn: page frame number to lookup page_map
- * @pgmap: optional known pgmap that already has a reference
- *
- * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in the
- * same mapping.
- */
-static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
- struct dev_pagemap *pgmap)
-{
- const struct resource *res = pgmap ? pgmap->res : NULL;
- resource_size_t phys = PFN_PHYS(pfn);
-
- /*
-* In the cached case we're already holding a live reference so
-* we can simply do a blind increment
-*/
- if (res && phys >= res->start && phys <= res->end) {
- percpu_ref_get(pgmap->ref);
- return pgmap;
- }
-
- /* fall back to slow path lookup */
- rcu_read_lock();
- pgmap = find_dev_pagemap(phys);
- if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
- pgmap = NULL;
- rcu_read_unlock();
-
- return pgmap;
-}
-
static inline void put_dev_pagemap(struct dev_pagemap *pgmap)
{
if (pgmap)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 64b12c806cc5..3df6cd4ffb40 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -314,7 +314,7 @@ static void devm_memremap_pages_release(struct device *dev,
void *data)
}
/* assumes rcu_read_lock() held at entry */
-struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+static struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
{
struct page_map *page_map;
@@ -501,8 +501,40 @@ struct vmem_altmap *to_vmem_altmap(unsigned long
memmap_start)
return pgmap ? pgmap->altmap : NULL;
}
-#endif /* CONFIG_ZONE_DEVICE */
+/**
+ * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
+ * @pfn: page frame number to lookup page_map
+ * @pgmap: optional known pgmap that already has a reference
+ *
+ * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in the
+ * same mapping.
+ */
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap)
+{
+ const struct resource *res = pgmap ? pgmap->res : NULL;
+ resource_size_t phys = PFN_PHYS(pfn);
+
+ /*
+* In the cached case we're already holding a live reference so
+* we can simply do a blind increment
+*/
+ if (res && phys >= res->start && phys <= res->end) {
+ percpu_ref_get(pgmap->ref);
+ return pgmap;
+ }
+
+ /* fall back to slow path lookup */
+ rcu_read_lock();
+ pgmap = find_dev_pagemap(phys);
+ if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
+ pgmap = NULL;
+ rcu_read_unlock();
+
+ return pgmap;
+}
+#endif /* CONFIG_ZONE_DEVICE */
#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC)
void put_zone_device_private_or_public_page(struct page *page)
--
2.14.2
Re: [PATCH 11/17] mm: move get_dev_pagemap out of line
On Fri, Dec 15, 2017 at 6:09 AM, Christoph Hellwig wrote:
> This is a pretty big function, which should be out of line in general,
> and a no-op stub if CONFIG_ZONE_DEVICЕ is not set.
>
> Signed-off-by: Christoph Hellwig
> Reviewed-by: Logan Gunthorpe
[..]
> +/**
> + * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
> + * @pfn: page frame number to lookup page_map
> + * @pgmap: optional known pgmap that already has a reference
> + *
> + * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in
> the
> + * same mapping.
> + */
> +struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
> + struct dev_pagemap *pgmap)
> +{
> + const struct resource *res = pgmap ? pgmap->res : NULL;
> + resource_size_t phys = PFN_PHYS(pfn);
> +
> + /*
> +* In the cached case we're already holding a live reference so
> +* we can simply do a blind increment
> +*/
> + if (res && phys >= res->start && phys <= res->end) {
> + percpu_ref_get(pgmap->ref);
> + return pgmap;
> + }
I was going to say keep the cached case in the static inline, but with
the optimization to the calling convention in the following patch I
think that makes this moot.
So,
Reviewed-by: Dan Williams
[PATCH 11/17] mm: move get_dev_pagemap out of line
This is a pretty big function, which should be out of line in general,
and a no-op stub if CONFIG_ZONE_DEVICЕ is not set.
Signed-off-by: Christoph Hellwig
Reviewed-by: Logan Gunthorpe
---
include/linux/memremap.h | 39 ---
kernel/memremap.c| 36 ++--
2 files changed, 38 insertions(+), 37 deletions(-)
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index d5a6736d9737..26e8aaba27d5 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -133,7 +133,8 @@ struct dev_pagemap {
#ifdef CONFIG_ZONE_DEVICE
void *devm_memremap_pages(struct device *dev, struct resource *res,
struct percpu_ref *ref, struct vmem_altmap *altmap);
-struct dev_pagemap *find_dev_pagemap(resource_size_t phys);
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap);
unsigned long vmem_altmap_offset(struct vmem_altmap *altmap);
void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns);
@@ -153,7 +154,8 @@ static inline void *devm_memremap_pages(struct device *dev,
return ERR_PTR(-ENXIO);
}
-static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap)
{
return NULL;
}
@@ -183,39 +185,6 @@ static inline bool is_device_public_page(const struct page
*page)
}
#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
-/**
- * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
- * @pfn: page frame number to lookup page_map
- * @pgmap: optional known pgmap that already has a reference
- *
- * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in the
- * same mapping.
- */
-static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
- struct dev_pagemap *pgmap)
-{
- const struct resource *res = pgmap ? pgmap->res : NULL;
- resource_size_t phys = PFN_PHYS(pfn);
-
- /*
-* In the cached case we're already holding a live reference so
-* we can simply do a blind increment
-*/
- if (res && phys >= res->start && phys <= res->end) {
- percpu_ref_get(pgmap->ref);
- return pgmap;
- }
-
- /* fall back to slow path lookup */
- rcu_read_lock();
- pgmap = find_dev_pagemap(phys);
- if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
- pgmap = NULL;
- rcu_read_unlock();
-
- return pgmap;
-}
-
static inline void put_dev_pagemap(struct dev_pagemap *pgmap)
{
if (pgmap)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 8e85803b6b0e..43d94db97ff4 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -314,7 +314,7 @@ static void devm_memremap_pages_release(struct device *dev,
void *data)
}
/* assumes rcu_read_lock() held at entry */
-struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+static struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
{
struct page_map *page_map;
@@ -500,8 +500,40 @@ struct vmem_altmap *to_vmem_altmap(unsigned long
memmap_start)
return pgmap ? pgmap->altmap : NULL;
}
-#endif /* CONFIG_ZONE_DEVICE */
+/**
+ * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
+ * @pfn: page frame number to lookup page_map
+ * @pgmap: optional known pgmap that already has a reference
+ *
+ * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in the
+ * same mapping.
+ */
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap)
+{
+ const struct resource *res = pgmap ? pgmap->res : NULL;
+ resource_size_t phys = PFN_PHYS(pfn);
+
+ /*
+* In the cached case we're already holding a live reference so
+* we can simply do a blind increment
+*/
+ if (res && phys >= res->start && phys <= res->end) {
+ percpu_ref_get(pgmap->ref);
+ return pgmap;
+ }
+
+ /* fall back to slow path lookup */
+ rcu_read_lock();
+ pgmap = find_dev_pagemap(phys);
+ if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
+ pgmap = NULL;
+ rcu_read_unlock();
+
+ return pgmap;
+}
+#endif /* CONFIG_ZONE_DEVICE */
#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC)
void put_zone_device_private_or_public_page(struct page *page)
--
2.14.2
