mm: remove rest of ACCESS_ONCE() usages
We converted some of the usages of ACCESS_ONCE to READ_ONCE in the mm/
tree since it doesn't work reliably on non-scalar types.
This patch removes the rest of the usages of ACCESS_ONCE, and use the new
READ_ONCE API for the read accesses. This makes things cleaner, instead
of using separate/multiple sets of APIs.
Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/ksm.c b/mm/ksm.c
index 4162dce..7ee101e 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -542,7 +542,7 @@
expected_mapping = (void *)stable_node +
(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
again:
- kpfn = ACCESS_ONCE(stable_node->kpfn);
+ kpfn = READ_ONCE(stable_node->kpfn);
page = pfn_to_page(kpfn);
/*
@@ -551,7 +551,7 @@
* but on Alpha we need to be more careful.
*/
smp_read_barrier_depends();
- if (ACCESS_ONCE(page->mapping) != expected_mapping)
+ if (READ_ONCE(page->mapping) != expected_mapping)
goto stale;
/*
@@ -577,14 +577,14 @@
cpu_relax();
}
- if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+ if (READ_ONCE(page->mapping) != expected_mapping) {
put_page(page);
goto stale;
}
if (lock_it) {
lock_page(page);
- if (ACCESS_ONCE(page->mapping) != expected_mapping) {
+ if (READ_ONCE(page->mapping) != expected_mapping) {
unlock_page(page);
put_page(page);
goto stale;
@@ -600,7 +600,7 @@
* before checking whether node->kpfn has been changed.
*/
smp_rmb();
- if (ACCESS_ONCE(stable_node->kpfn) != kpfn)
+ if (READ_ONCE(stable_node->kpfn) != kpfn)
goto again;
remove_node_from_stable_tree(stable_node);
return NULL;