Messages in this thread Patch in this message | | | Subject | [PATCH -next] mm/rmap: calculate page offset when needed | From | Davidlohr Bueso <> | Date | Fri, 07 Nov 2014 11:34:17 -0800 |
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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> --- mm/rmap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c index a5e9cc6..e3354b2 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1633,7 +1633,7 @@ 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; @@ -1641,6 +1641,7 @@ 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); @@ -1674,7 +1675,7 @@ 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; @@ -1689,6 +1690,7 @@ 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); -- 1.8.4.5
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