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| author | Davidlohr Bueso <dave@stgolabs.net> | 2014-12-12 16:55:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:46 -0800 |
| commit | b258d860652934b5e014408302335430b81bd7ce (patch) | |
| tree | 2c6735a682f865dec8cb85504b4667fe219112dc /mm/rmap.c | |
| parent | 2847cf95c68fa5fa391c58a669e761c4b0c8fc57 (diff) | |
| download | lwn-b258d860652934b5e014408302335430b81bd7ce.tar.gz lwn-b258d860652934b5e014408302335430b81bd7ce.zip | |
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.c | 6 |
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); |