Cc: LKML <linux-kernel@...>, Andi Kleen <ak@...>, Jan Beulich <jbeulich@...>, Eduardo Pereira Habkost <ehabkost@...>, Ian Campbell <ijc@...>, H Peter Anvin <hpa@...>
If SHARED_KERNEL_PMD is false, then we need to allocate and initialize
the kernel pmd. We can easily piggy-back this onto the existing pmd
prepopulation code.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
---
arch/x86/mm/pgtable_32.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -269,7 +269,7 @@ static void pgd_mop_up_pmds(pgd_t *pgdp)
{
int i;
- for(i = 0; i < USER_PTRS_PER_PGD; i++) {
+ for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) {
pgd_t pgd = pgdp[i];
if (pgd_val(pgd) != 0) {
@@ -289,6 +289,10 @@ static void pgd_mop_up_pmds(pgd_t *pgdp)
* processor notices the update. Since this is expensive, and
* all 4 top-level entries are used almost immediately in a
* new process's life, we just pre-populate them here.
+ *
+ * Also, if we're in a paravirt environment where the kernel pmd is
+ * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
+ * and initialize the kernel pmds here.
*/
static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd)
{
@@ -297,13 +301,18 @@ static int pgd_prepopulate_pmd(struct mm
int i;
pud = pud_offset(pgd, 0);
- for (addr = i = 0; i < USER_PTRS_PER_PGD; i++, pud++, addr += PUD_SIZE) {
+ for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD;
+ i++, pud++, addr += PUD_SIZE) {
pmd_t *pmd = pmd_alloc_one(mm, addr);
if (!pmd) {
pgd_mop_up_pmds(pgd);
return 0;
}
+
+ if (i >= USER_PTRS_PER_PGD)
+ memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
+ sizeof(pmd_t) * PTRS_PER_PMD);
pud_populate(mm, pud, pmd);
}
@@ -346,4 +355,3 @@ void check_pgt_cache(void)
{
quicklist_trim(0, pgd_dtor, 25, 16);
}
-
--
