diff options
author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-10-09 11:51:45 -0700 |
---|---|---|
committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-12-04 10:52:56 -0800 |
commit | 08df477434754629303c9e2bfa8d67ecb44f9c20 (patch) | |
tree | 98e412d75e903798d8332f9760a2f660c6c76a1c | |
parent | 516df050615e4b0fd2dd0448cb5a807208a3837a (diff) |
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@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: <linux-mm@kvack.org>
-rw-r--r-- | mm/ksm.c | 9 |
1 files changed, 1 insertions, 8 deletions
@@ -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; |