[ARM SMP] Disable lazy flush_dcache_page for SMP

Lazy flush_dcache_page() causes userspace instability on SMP
platforms, so disable it for now.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index c9a0398..330695b 100644 (file)
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -155,14 +155,19 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
  *  space mappings, we can be lazy and remember that we may have dirty
  *  kernel cache lines for later.  Otherwise, we assume we have
  *  aliasing mappings.
+ *
+ * Note that we disable the lazy flush for SMP.
  */
 void flush_dcache_page(struct page *page)
 {
        struct address_space *mapping = page_mapping(page);
 
+#ifndef CONFIG_SMP
        if (mapping && !mapping_mapped(mapping))
                set_bit(PG_dcache_dirty, &page->flags);
-       else {
+       else
+#endif
+       {
                __flush_dcache_page(mapping, page);
                if (mapping && cache_is_vivt())
                        __flush_dcache_aliases(mapping, page);