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Commit 508bebbb authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

x86: allocate and initialize unshared pmds 



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: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 8fe3deef

arch/x86/mm/pgtable_32.c

+11 −3
Original line number Diff line number Diff line
@@ -305,7 +305,7 @@ 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) {
@@ -325,6 +325,10 @@ 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)

{
@@ -333,7 +337,8 @@ static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd) 
	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) {
@@ -341,6 +346,10 @@ static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *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);

	}
@@ -444,4 +453,3 @@ void check_pgt_cache(void) 
{

	quicklist_trim(0, pgd_dtor, 25, 16);

}