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authorDavidlohr Bueso <dave@stgolabs.net>2014-12-12 16:55:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 12:42:46 -0800
commitb258d860652934b5e014408302335430b81bd7ce (patch)
tree2c6735a682f865dec8cb85504b4667fe219112dc /mm/rmap.c
parent2847cf95c68fa5fa391c58a669e761c4b0c8fc57 (diff)
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mm/rmap: calculate page offset when needed
Call page_to_pgoff() to get the page offset once we are sure we actually need it, and any very obvious initial function checks have passed. Trivial micro-optimization, and potentially save some cycles. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 14ad2b3b0f54..c52f43a69eea 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1635,7 +1635,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
{
struct anon_vma *anon_vma;
- pgoff_t pgoff = page_to_pgoff(page);
+ pgoff_t pgoff;
struct anon_vma_chain *avc;
int ret = SWAP_AGAIN;
@@ -1643,6 +1643,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
if (!anon_vma)
return ret;
+ pgoff = page_to_pgoff(page);
anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
@@ -1676,7 +1677,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
{
struct address_space *mapping = page->mapping;
- pgoff_t pgoff = page_to_pgoff(page);
+ pgoff_t pgoff;
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
@@ -1691,6 +1692,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
if (!mapping)
return ret;
+ pgoff = page_to_pgoff(page);
i_mmap_lock_read(mapping);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);