From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Wed, 30 Nov 2005 16:02:54 +0000 (+0000)
Subject: [ARM SMP] Disable lazy flush_dcache_page for SMP
X-Git-Tag: v2.6.15-rc5~17^2~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df2f5e721ed36e21da27e1f415c71ba0e20f31b5;p=linux-2.6

[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 c9a03981b7..330695b6b1 100644
--- 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);