From 8eb5baecb9b8a5baf5acebbc568432d29d921b16 Mon Sep 17 00:00:00 2001 From: Piotr Kwapulinski Date: Wed, 24 Jun 2015 16:58:39 -0700 Subject: [PATCH] mm/mmap.c: optimization of do_mmap_pgoff function The simple check for zero length memory mapping may be performed earlier. So that in case of zero length memory mapping some unnecessary code is not executed at all. It does not make the code less readable and saves some CPU cycles. Signed-off-by: Piotr Kwapulinski Acked-by: Michal Hocko Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index bb50cacc3ea57..aa632ade2be79 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1258,6 +1258,9 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, *populate = 0; + if (!len) + return -EINVAL; + /* * Does the application expect PROT_READ to imply PROT_EXEC? * @@ -1268,9 +1271,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, if (!(file && (file->f_path.mnt->mnt_flags & MNT_NOEXEC))) prot |= PROT_EXEC; - if (!len) - return -EINVAL; - if (!(flags & MAP_FIXED)) addr = round_hint_to_min(addr); -- 2.39.5