[patch 6/9] mm + fs: provide shadow pages to page cache allocations
From: Johannes Weiner
Date: Sat Aug 17 2013 - 15:34:37 EST
In order to make informed placement and reclaim decisions, the page
cache allocation requires the shadow information of refaulting pages.
Every site that does a find_or_create()-style page cache allocation is
converted to pass the shadow page found in the faulting slot of the
radix tree to page_cache_alloc(), where it can be used in subsequent
patches to influence reclaim behavior.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
drivers/staging/lustre/lustre/llite/dir.c | 2 +-
fs/btrfs/compression.c | 2 +-
fs/cachefiles/rdwr.c | 13 +++++----
fs/ceph/xattr.c | 2 +-
fs/logfs/readwrite.c | 6 ++--
fs/ntfs/file.c | 7 +++--
fs/splice.c | 6 ++--
include/linux/pagemap.h | 20 ++++++++------
mm/filemap.c | 46 +++++++++++++++++--------------
mm/readahead.c | 2 +-
net/ceph/pagelist.c | 4 +--
net/ceph/pagevec.c | 2 +-
12 files changed, 61 insertions(+), 51 deletions(-)
diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index 2ca8c45..ac63e4d 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -172,7 +172,7 @@ static int ll_dir_filler(void *_hash, struct page *page0)
max_pages = 1;
}
for (npages = 1; npages < max_pages; npages++) {
- page = page_cache_alloc_cold(inode->i_mapping);
+ page = page_cache_alloc_cold(inode->i_mapping, NULL);
if (!page)
break;
page_pool[npages] = page;
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 5ce2c0f..f23bb17 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -483,7 +483,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
}
page = __page_cache_alloc(mapping_gfp_mask(mapping) &
- ~__GFP_FS);
+ ~__GFP_FS, page);
if (!page)
break;
diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index ebaff36..1b34a42 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -254,13 +254,13 @@ static int cachefiles_read_backing_file_one(struct cachefiles_object *object,
newpage = NULL;
for (;;) {
- backpage = find_get_page(bmapping, netpage->index);
- if (backpage)
+ backpage = __find_get_page(bmapping, netpage->index);
+ if (backpage && !radix_tree_exceptional_entry(backpage))
goto backing_page_already_present;
if (!newpage) {
newpage = __page_cache_alloc(cachefiles_gfp |
- __GFP_COLD);
+ __GFP_COLD, backpage);
if (!newpage)
goto nomem_monitor;
}
@@ -499,13 +499,14 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
}
for (;;) {
- backpage = find_get_page(bmapping, netpage->index);
- if (backpage)
+ backpage = __find_get_page(bmapping, netpage->index);
+ if (backpage && !radix_tree_exceptional_entry(backpage))
goto backing_page_already_present;
if (!newpage) {
newpage = __page_cache_alloc(cachefiles_gfp |
- __GFP_COLD);
+ __GFP_COLD,
+ backpage);
if (!newpage)
goto nomem;
}
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index be661d8..a5d2b86 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -816,7 +816,7 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
return -ENOMEM;
err = -ENOMEM;
for (i = 0; i < nr_pages; i++) {
- pages[i] = __page_cache_alloc(GFP_NOFS);
+ pages[i] = __page_cache_alloc(GFP_NOFS, NULL);
if (!pages[i]) {
nr_pages = i;
goto out;
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 9a59cba..67c669a 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -316,9 +316,9 @@ static struct page *logfs_get_write_page(struct inode *inode, u64 bix,
int err;
repeat:
- page = find_get_page(mapping, index);
- if (!page) {
- page = __page_cache_alloc(GFP_NOFS);
+ page = __find_get_page(mapping, index);
+ if (!page || radix_tree_exceptional_entry(page)) {
+ page = __page_cache_alloc(GFP_NOFS, page);
if (!page)
return NULL;
err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index c5670b8..7aee2d1 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -413,10 +413,11 @@ static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
BUG_ON(!nr_pages);
err = nr = 0;
do {
- pages[nr] = find_lock_page(mapping, index);
- if (!pages[nr]) {
+ pages[nr] = __find_lock_page(mapping, index);
+ if (!pages[nr] || radix_tree_exceptional_entry(pages[nr])) {
if (!*cached_page) {
- *cached_page = page_cache_alloc(mapping);
+ *cached_page = page_cache_alloc(mapping,
+ pages[nr]);
if (unlikely(!*cached_page)) {
err = -ENOMEM;
goto err_out;
diff --git a/fs/splice.c b/fs/splice.c
index 3b7ee65..edc54ae 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -353,12 +353,12 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
* Page could be there, find_get_pages_contig() breaks on
* the first hole.
*/
- page = find_get_page(mapping, index);
- if (!page) {
+ page = __find_get_page(mapping, index);
+ if (!page || radix_tree_exceptional_entry(page)) {
/*
* page didn't exist, allocate one.
*/
- page = page_cache_alloc_cold(mapping);
+ page = page_cache_alloc_cold(mapping, page);
if (!page)
break;
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index db3a78b..4b24236 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -228,28 +228,32 @@ static inline void page_unfreeze_refs(struct page *page, int count)
}
#ifdef CONFIG_NUMA
-extern struct page *__page_cache_alloc(gfp_t gfp);
+extern struct page *__page_cache_alloc(gfp_t gfp, struct page *shadow);
#else
-static inline struct page *__page_cache_alloc(gfp_t gfp)
+static inline struct page *__page_cache_alloc(gfp_t gfp, struct page *shadow)
{
return alloc_pages(gfp, 0);
}
#endif
-static inline struct page *page_cache_alloc(struct address_space *x)
+static inline struct page *page_cache_alloc(struct address_space *x,
+ struct page *shadow)
{
- return __page_cache_alloc(mapping_gfp_mask(x));
+ return __page_cache_alloc(mapping_gfp_mask(x), shadow);
}
-static inline struct page *page_cache_alloc_cold(struct address_space *x)
+static inline struct page *page_cache_alloc_cold(struct address_space *x,
+ struct page *shadow)
{
- return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD);
+ return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD, shadow);
}
-static inline struct page *page_cache_alloc_readahead(struct address_space *x)
+static inline struct page *page_cache_alloc_readahead(struct address_space *x,
+ struct page *shadow)
{
return __page_cache_alloc(mapping_gfp_mask(x) |
- __GFP_COLD | __GFP_NORETRY | __GFP_NOWARN);
+ __GFP_COLD | __GFP_NORETRY | __GFP_NOWARN,
+ shadow);
}
typedef int filler_t(void *, struct page *);
diff --git a/mm/filemap.c b/mm/filemap.c
index 34b2f0b..d3e5578 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -538,7 +538,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
#ifdef CONFIG_NUMA
-struct page *__page_cache_alloc(gfp_t gfp)
+struct page *__page_cache_alloc(gfp_t gfp, struct page *shadow)
{
int n;
struct page *page;
@@ -917,9 +917,9 @@ struct page *find_or_create_page(struct address_space *mapping,
struct page *page;
int err;
repeat:
- page = find_lock_page(mapping, index);
- if (!page) {
- page = __page_cache_alloc(gfp_mask);
+ page = __find_lock_page(mapping, index);
+ if (!page || radix_tree_exceptional_entry(page)) {
+ page = __page_cache_alloc(gfp_mask, page);
if (!page)
return NULL;
/*
@@ -1222,15 +1222,16 @@ EXPORT_SYMBOL(find_get_pages_tag);
struct page *
grab_cache_page_nowait(struct address_space *mapping, pgoff_t index)
{
- struct page *page = find_get_page(mapping, index);
+ struct page *page = __find_get_page(mapping, index);
- if (page) {
+ if (page && !radix_tree_exceptional_entry(page)) {
if (trylock_page(page))
return page;
page_cache_release(page);
return NULL;
}
- page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS);
+ page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS,
+ page);
if (page && add_to_page_cache_lru(page, mapping, index, GFP_NOFS)) {
page_cache_release(page);
page = NULL;
@@ -1304,8 +1305,9 @@ find_page:
page_cache_sync_readahead(mapping,
ra, filp,
index, last_index - index);
- page = find_get_page(mapping, index);
- if (unlikely(page == NULL))
+ page = __find_get_page(mapping, index);
+ if (unlikely(page == NULL ||
+ radix_tree_exceptional_entry(page)))
goto no_cached_page;
}
if (PageReadahead(page)) {
@@ -1464,7 +1466,7 @@ no_cached_page:
* Ok, it wasn't cached, so we need to create a new
* page..
*/
- page = page_cache_alloc_cold(mapping);
+ page = page_cache_alloc_cold(mapping, page);
if (!page) {
desc->error = -ENOMEM;
goto out;
@@ -1673,18 +1675,20 @@ EXPORT_SYMBOL(generic_file_aio_read);
* page_cache_read - adds requested page to the page cache if not already there
* @file: file to read
* @offset: page index
+ * @shadow: shadow page of the page to be added
*
* This adds the requested page to the page cache if it isn't already there,
* and schedules an I/O to read in its contents from disk.
*/
-static int page_cache_read(struct file *file, pgoff_t offset)
+static int page_cache_read(struct file *file, pgoff_t offset,
+ struct page *shadow)
{
struct address_space *mapping = file->f_mapping;
struct page *page;
int ret;
do {
- page = page_cache_alloc_cold(mapping);
+ page = page_cache_alloc_cold(mapping, shadow);
if (!page)
return -ENOMEM;
@@ -1815,8 +1819,8 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
ret = VM_FAULT_MAJOR;
retry_find:
- page = find_get_page(mapping, offset);
- if (!page)
+ page = __find_get_page(mapping, offset);
+ if (!page || radix_tree_exceptional_entry(page))
goto no_cached_page;
}
@@ -1859,7 +1863,7 @@ no_cached_page:
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
- error = page_cache_read(file, offset);
+ error = page_cache_read(file, offset, page);
/*
* The page we want has now been added to the page cache.
@@ -1981,9 +1985,9 @@ static struct page *__read_cache_page(struct address_space *mapping,
struct page *page;
int err;
repeat:
- page = find_get_page(mapping, index);
- if (!page) {
- page = __page_cache_alloc(gfp | __GFP_COLD);
+ page = __find_get_page(mapping, index);
+ if (!page || radix_tree_exceptional_entry(page)) {
+ page = __page_cache_alloc(gfp | __GFP_COLD, page);
if (!page)
return ERR_PTR(-ENOMEM);
err = add_to_page_cache_lru(page, mapping, index, gfp);
@@ -2454,11 +2458,11 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping,
if (flags & AOP_FLAG_NOFS)
gfp_notmask = __GFP_FS;
repeat:
- page = find_lock_page(mapping, index);
- if (page)
+ page = __find_lock_page(mapping, index);
+ if (page && !radix_tree_exceptional_entry(page))
goto found;
- page = __page_cache_alloc(gfp_mask & ~gfp_notmask);
+ page = __page_cache_alloc(gfp_mask & ~gfp_notmask, page);
if (!page)
return NULL;
status = add_to_page_cache_lru(page, mapping, index,
diff --git a/mm/readahead.c b/mm/readahead.c
index 0f85996..58142ef 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -182,7 +182,7 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
if (page && !radix_tree_exceptional_entry(page))
continue;
- page = page_cache_alloc_readahead(mapping);
+ page = page_cache_alloc_readahead(mapping, page);
if (!page)
break;
page->index = page_offset;
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
index 92866be..83fb56e 100644
--- a/net/ceph/pagelist.c
+++ b/net/ceph/pagelist.c
@@ -32,7 +32,7 @@ static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
struct page *page;
if (!pl->num_pages_free) {
- page = __page_cache_alloc(GFP_NOFS);
+ page = __page_cache_alloc(GFP_NOFS, NULL);
} else {
page = list_first_entry(&pl->free_list, struct page, lru);
list_del(&page->lru);
@@ -83,7 +83,7 @@ int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space)
space = (space + PAGE_SIZE - 1) >> PAGE_SHIFT; /* conv to num pages */
while (space > pl->num_pages_free) {
- struct page *page = __page_cache_alloc(GFP_NOFS);
+ struct page *page = __page_cache_alloc(GFP_NOFS, NULL);
if (!page)
return -ENOMEM;
list_add_tail(&page->lru, &pl->free_list);
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
index 815a224..ff76422 100644
--- a/net/ceph/pagevec.c
+++ b/net/ceph/pagevec.c
@@ -79,7 +79,7 @@ struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
if (!pages)
return ERR_PTR(-ENOMEM);
for (i = 0; i < num_pages; i++) {
- pages[i] = __page_cache_alloc(flags);
+ pages[i] = __page_cache_alloc(flags, NULL);
if (pages[i] == NULL) {
ceph_release_page_vector(pages, i);
return ERR_PTR(-ENOMEM);
--
1.8.3.2
--
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