[patch 06/10] mm + fs: prepare for non-page entries in page cache radix trees
shmem mappings already contain exceptional entries where swap slot
information is remembered.
To be able to store eviction information for regular page cache,
prepare every site dealing with the radix trees directly to handle
entries other than pages.
The common lookup functions will filter out non-page entries and
return NULL for page cache holes, just as before. But provide a raw
version of the API which returns non-page entries as well, and switch
shmem over to use it.
Signed-off-by: Johannes Weiner
Reviewed-by: Rik van Riel
Reviewed-by: Minchan Kim
---
fs/btrfs/compression.c | 2 +-
include/linux/mm.h | 8 ++
include/linux/pagemap.h | 15 ++--
include/linux/pagevec.h | 3 +
include/linux/shmem_fs.h | 1 +
mm/filemap.c | 197 +--
mm/mincore.c | 20 +++--
mm/readahead.c | 2 +-
mm/shmem.c | 97 +--
mm/swap.c| 48
mm/truncate.c| 73 ++
11 files changed, 338 insertions(+), 128 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e2600cdb6c25..1b8d21b681f2 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -472,7 +472,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
rcu_read_lock();
page = radix_tree_lookup(>page_tree, pg_index);
rcu_read_unlock();
- if (page) {
+ if (page && !radix_tree_exceptional_entry(page)) {
misses++;
if (misses > 4)
break;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f28f46eade6a..d684ac125482 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1031,6 +1031,14 @@ extern void show_free_areas(unsigned int flags);
extern bool skip_free_areas_node(unsigned int flags, int nid);
int shmem_zero_setup(struct vm_area_struct *);
+#ifdef CONFIG_SHMEM
+bool shmem_mapping(struct address_space *mapping);
+#else
+static inline bool shmem_mapping(struct address_space *mapping)
+{
+ return false;
+}
+#endif
extern int can_do_mlock(void);
extern int user_shm_lock(size_t, struct user_struct *);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 52d56872fe26..2eeca3c83b0f 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -248,12 +248,15 @@ pgoff_t page_cache_next_hole(struct address_space
*mapping,
pgoff_t page_cache_prev_hole(struct address_space *mapping,
pgoff_t index, unsigned long max_scan);
-extern struct page * find_get_page(struct address_space *mapping,
- pgoff_t index);
-extern struct page * find_lock_page(struct address_space *mapping,
- pgoff_t index);
-extern struct page * find_or_create_page(struct address_space *mapping,
- pgoff_t index, gfp_t gfp_mask);
+struct page *__find_get_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_get_page(struct address_space *mapping, pgoff_t offset);
+struct page *__find_lock_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_lock_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_or_create_page(struct address_space *mapping, pgoff_t index,
+gfp_t gfp_mask);
+unsigned __find_get_pages(struct address_space *mapping, pgoff_t start,
+ unsigned int nr_pages, struct page **pages,
+ pgoff_t *indices);
unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
unsigned int nr_pages, struct page **pages);
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index e4dbfab37729..3c6b8b1e945b 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -22,6 +22,9 @@ struct pagevec {
void __pagevec_release(struct pagevec *pvec);
void __pagevec_lru_add(struct pagevec *pvec);
+unsigned __pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
+ pgoff_t start, unsigned nr_pages, pgoff_t *indices);
+void pagevec_remove_exceptionals(struct pagevec *pvec);
unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
pgoff_t start, unsigned nr_pages);
unsigned pagevec_lookup_tag(struct pagevec *pvec,
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 9d55438bc4ad..4d1771c2d29f 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -51,6 +51,7 @@ extern struct file *shmem_kernel_file_setup(const char *name,
loff_t size,
unsigned long flags);
extern int shmem_zero_setup(struct vm_area_struct *);
extern int shmem_lock(struct file *file, int
[patch 06/10] mm + fs: prepare for non-page entries in page cache radix trees
shmem mappings already contain exceptional entries where swap slot
information is remembered.
To be able to store eviction information for regular page cache,
prepare every site dealing with the radix trees directly to handle
entries other than pages.
The common lookup functions will filter out non-page entries and
return NULL for page cache holes, just as before. But provide a raw
version of the API which returns non-page entries as well, and switch
shmem over to use it.
Signed-off-by: Johannes Weiner han...@cmpxchg.org
Reviewed-by: Rik van Riel r...@redhat.com
Reviewed-by: Minchan Kim minc...@kernel.org
---
fs/btrfs/compression.c | 2 +-
include/linux/mm.h | 8 ++
include/linux/pagemap.h | 15 ++--
include/linux/pagevec.h | 3 +
include/linux/shmem_fs.h | 1 +
mm/filemap.c | 197 +--
mm/mincore.c | 20 +++--
mm/readahead.c | 2 +-
mm/shmem.c | 97 +--
mm/swap.c| 48
mm/truncate.c| 73 ++
11 files changed, 338 insertions(+), 128 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e2600cdb6c25..1b8d21b681f2 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -472,7 +472,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
rcu_read_lock();
page = radix_tree_lookup(mapping-page_tree, pg_index);
rcu_read_unlock();
- if (page) {
+ if (page !radix_tree_exceptional_entry(page)) {
misses++;
if (misses 4)
break;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f28f46eade6a..d684ac125482 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1031,6 +1031,14 @@ extern void show_free_areas(unsigned int flags);
extern bool skip_free_areas_node(unsigned int flags, int nid);
int shmem_zero_setup(struct vm_area_struct *);
+#ifdef CONFIG_SHMEM
+bool shmem_mapping(struct address_space *mapping);
+#else
+static inline bool shmem_mapping(struct address_space *mapping)
+{
+ return false;
+}
+#endif
extern int can_do_mlock(void);
extern int user_shm_lock(size_t, struct user_struct *);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 52d56872fe26..2eeca3c83b0f 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -248,12 +248,15 @@ pgoff_t page_cache_next_hole(struct address_space
*mapping,
pgoff_t page_cache_prev_hole(struct address_space *mapping,
pgoff_t index, unsigned long max_scan);
-extern struct page * find_get_page(struct address_space *mapping,
- pgoff_t index);
-extern struct page * find_lock_page(struct address_space *mapping,
- pgoff_t index);
-extern struct page * find_or_create_page(struct address_space *mapping,
- pgoff_t index, gfp_t gfp_mask);
+struct page *__find_get_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_get_page(struct address_space *mapping, pgoff_t offset);
+struct page *__find_lock_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_lock_page(struct address_space *mapping, pgoff_t offset);
+struct page *find_or_create_page(struct address_space *mapping, pgoff_t index,
+gfp_t gfp_mask);
+unsigned __find_get_pages(struct address_space *mapping, pgoff_t start,
+ unsigned int nr_pages, struct page **pages,
+ pgoff_t *indices);
unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
unsigned int nr_pages, struct page **pages);
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index e4dbfab37729..3c6b8b1e945b 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -22,6 +22,9 @@ struct pagevec {
void __pagevec_release(struct pagevec *pvec);
void __pagevec_lru_add(struct pagevec *pvec);
+unsigned __pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
+ pgoff_t start, unsigned nr_pages, pgoff_t *indices);
+void pagevec_remove_exceptionals(struct pagevec *pvec);
unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
pgoff_t start, unsigned nr_pages);
unsigned pagevec_lookup_tag(struct pagevec *pvec,
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 9d55438bc4ad..4d1771c2d29f 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -51,6 +51,7 @@ extern struct file *shmem_kernel_file_setup(const char *name,
loff_t size,
unsigned long flags);
extern int shmem_zero_setup(struct vm_area_struct
