On 04/01/2011 09:06 AM, Yinghai Lu wrote:Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -294,10 +294,17 @@ static void __init init_gbpages(void)
else
direct_gbpages = 0;
}
+static void __init store_mmu_cr4(void)
+{
+ mmu_cr4_features = read_cr4();
+}
#else
static inline void init_gbpages(void)
{
}
+static void __init store_mmu_cr4(void)
+{
+}
static void __init cleanup_highmap(void)
{
}
@@ -929,6 +936,8 @@ void __init setup_arch(char **cmdline_p)
/* max_pfn_mapped is updated here */
max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
max_pfn_mapped = max_low_pfn_mapped;
+ /* after init_memory_mapping updating cr4*/
+ store_mmu_cr4();
#ifdef CONFIG_X86_64
if (max_pfn> max_low_pfn) {
This looks really, really, really wrong.
Why the heck should we save and restore CR4 only for x86-64?