page fault scalability patch V8: [6/7] atomic pte operations for x86_64

Christoph Lameter
2004-09-18T23:37:31Z

Changelog
* Provide atomic pte operations for x86_64

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linus/include/asm-x86_64/pgalloc.h
===================================================================
--- linus.orig/include/asm-x86_64/pgalloc.h 2004-09-18 14:25:23.000000000 -0700
+++ linus/include/asm-x86_64/pgalloc.h 2004-09-18 14:25:23.000000000 -0700
@@ -7,16 +7,26 @@
#include <linux/threads.h>
#include <linux/mm.h>

+#define PMD_NONE 0
+#define PGD_NONE 0
+
#define pmd_populate_kernel(mm, pmd, pte) \
set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)))
#define pgd_populate(mm, pgd, pmd) \
set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pmd)))
+#define pgd_test_and_populate(mm, pgd, pmd) \
+ (cmpxchg(pgd, PGD_NONE, _PAGE_TABLE | __pa(pmd)) == PGD_NONE)

static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
{
set_pmd(pmd, __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)));
}

+static inline int pmd_test_and_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
+{
+ return cmpxchg(pmd, PMD_NONE, _PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)) == PMD_NONE;
+}
+
extern __inline__ pmd_t *get_pmd(void)
{
return (pmd_t *)get_zeroed_page(GFP_KERNEL);
Index: linus/include/asm-x86_64/pgtable.h
===================================================================
--- linus.orig/include/asm-x86_64/pgtable.h 2004-09-18 14:25:23.000000000 -0700
+++ linus/include/asm-x86_64/pgtable.h 2004-09-18 14:25:23.000000000 -0700
@@ -436,6 +436,11 @@
#define kc_offset_to_vaddr(o) \
(((o) & (1UL << (__VIRTUAL_MASK_SHIFT-1))) ? ((o) | (~__VIRTUAL_MASK)) : (o))

+
+#define ptep_xchg(mm,addr,xp,newval) __pte(xchg(&(xp)->pte, pte_val(newval))
+#define ptep_cmpxchg(mm,addr,xp,newval,oldval) (cmpxchg(&(xp)->pte, pte_val(newval), pte_val(oldval) == pte_val(oldval))
+#define __HAVE_ARCH_ATOMIC_TABLE_OPS
+
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR