1 files changed, 11 insertions, 0 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 40b7ac58e671..3810f7a83b1d 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -243,6 +243,17 @@ static int try_preserve_large_page(pte_t *kpte, unsigned long address,
         pgprot_t old_prot, new_prot;
         int level, res = CPA_SPLIT;
 
+        /*
+         * An Athlon 64 X2 showed hard hangs if we tried to preserve
+         * largepages and changed the PSE entry from RW to RO.
+         *
+         * As AMD CPUs have a long series of erratas in this area,
+         * (and none of the known ones seem to explain this hang),
+         * disable this code until the hang can be debugged:
+         */
+        if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+                return res;
+
         spin_lock_irqsave(&pgd_lock, flags);
         /*
          * Check for races, another CPU might have split this page