From 70af7c5c6492ef6ad137dbff6c4568c73edbcaf0 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Fri, 23 Jun 2006 02:03:44 -0700 Subject: [PATCH] [PATCH] swapoff: use atomic_inc_not_zero() on mm_users Now that we have atomic_inc_not_zero, it's more elegant for try_to_unuse to use that on mm_users: doesn't actually matter at present, but safer to be sure that once mm_users has gone to 0, nothing raises it for an instant. Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index fbceed6..f2824c3c3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -772,10 +772,8 @@ static int try_to_unuse(unsigned int type) while (*swap_map > 1 && !retval && (p = p->next) != &start_mm->mmlist) { mm = list_entry(p, struct mm_struct, mmlist); - if (atomic_inc_return(&mm->mm_users) == 1) { - atomic_dec(&mm->mm_users); + if (!atomic_inc_not_zero(&mm->mm_users)) continue; - } spin_unlock(&mmlist_lock); mmput(prev_mm); prev_mm = mm; -- 2.7.4