From: Jeremy Fitzhardinge Date: Wed, 30 Jan 2008 12:33:40 +0000 (+0100) Subject: x86: allocate and initialize unshared pmds X-Git-Tag: v2.6.25-rc1~1143^2~147 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=508bebbb1f211fbf3f392feea44218045096f240;p=linux-2.6 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: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index 33ddddfc26..3a6c920005 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -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); } -