lkml.org 
[lkml]   [2014]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 13/16] ksm: Replace smp_read_barrier_depends() with lockless_dereference()
Date
Recently lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the change.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
---
mm/ksm.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/ksm.c b/mm/ksm.c
index d247efa..a67de79 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -542,15 +542,14 @@ static struct page *get_ksm_page(struct stable_node *stable_node, bool lock_it)
expected_mapping = (void *)stable_node +
(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
again:
- kpfn = ACCESS_ONCE(stable_node->kpfn);
- 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();
+ kpfn = lockless_dereference(stable_node->kpfn);
+ page = pfn_to_page(kpfn);
+
if (ACCESS_ONCE(page->mapping) != expected_mapping)
goto stale;

--
1.9.1


\
 
 \ /
  Last update: 2014-11-13 20:41    [W:0.251 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site