Commit-ID: 08df477434754629303c9e2bfa8d67ecb44f9c20 Gitweb: https://git.kernel.org/tip/08df477434754629303c9e2bfa8d67ecb44f9c20 Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> AuthorDate: Mon, 9 Oct 2017 11:51:45 -0700 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Mon, 4 Dec 2017 10:52:56 -0800 mm/ksm: Remove now-redundant smp_read_barrier_depends() Because READ_ONCE() now implies smp_read_barrier_depends(), the smp_read_barrier_depends() in get_ksm_page() is now redundant. This commit removes it and updates the comments. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxxxxxxx> Cc: <linux-mm@xxxxxxxxx> --- mm/ksm.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/mm/ksm.c b/mm/ksm.c index be8f457..c406f75 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -675,15 +675,8 @@ static struct page *get_ksm_page(struct stable_node *stable_node, bool lock_it) expected_mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM); again: - kpfn = READ_ONCE(stable_node->kpfn); + kpfn = READ_ONCE(stable_node->kpfn); /* Address dependency. */ page = pfn_to_page(kpfn); - - /* - * page is computed from kpfn, so on most architectures reading - * page->mapping is naturally ordered after reading node->kpfn, - * but on Alpha we need to be more careful. - */ - smp_read_barrier_depends(); if (READ_ONCE(page->mapping) != expected_mapping) goto stale; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
