[PATCH] i386: pte xchg optimization

[net-next-2.6.git] / include / asm-i386 / pgtable-2level.h

diff --git a/include/asm-i386/pgtable-2level.h b/include/asm-i386/pgtable-2level.h
index 85d9005c0cdf9c42d1949fdb176b1a8e6208af15..3daab67cd3666e3465d6fbb46ad7c43b250c7a54 100644 (file)
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -41,10 +41,24 @@ static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, pt
        *xp = __pte(0);
 }
 
+/* local pte updates need not use xchg for locking */
+static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
+{
+       pte_t res;
+
+       res = *ptep;
+       native_pte_clear(NULL, 0, ptep);
+       return res;
+}
+
+#ifdef CONFIG_SMP
 static inline pte_t native_ptep_get_and_clear(pte_t *xp)
 {
        return __pte(xchg(&xp->pte_low, 0));
 }
+#else
+#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
+#endif
 
 #define pte_page(x)            pfn_to_page(pte_pfn(x))
 #define pte_none(x)            (!(x).pte_low)