diff options
| -rw-r--r-- | arch/x86/mm/pgtable.c | 62 |
1 files changed, 4 insertions, 58 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index a05fcddfc811..ea01b5572442 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -318,68 +318,15 @@ static void pgd_prepopulate_user_pmd(struct mm_struct *mm, { } #endif -/* - * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also - * assumes that pgd should be in one page. - * - * But kernel with PAE paging that is not running as a Xen domain - * only needs to allocate 32 bytes for pgd instead of one page. - */ -#ifdef CONFIG_X86_PAE - -#include <linux/slab.h> - -#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t)) -#define PGD_ALIGN 32 - -static struct kmem_cache *pgd_cache; - -void __init pgtable_cache_init(void) -{ - /* - * When PAE kernel is running as a Xen domain, it does not use - * shared kernel pmd. And this requires a whole page for pgd. - */ - if (!SHARED_KERNEL_PMD) - return; - - /* - * when PAE kernel is not running as a Xen domain, it uses - * shared kernel pmd. Shared kernel pmd does not require a whole - * page for pgd. We are able to just allocate a 32-byte for pgd. - * During boot time, we create a 32-byte slab for pgd table allocation. - */ - pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN, - SLAB_PANIC, NULL); -} static inline pgd_t *_pgd_alloc(struct mm_struct *mm) { /* - * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain. - * We allocate one page for pgd. - */ - if (!SHARED_KERNEL_PMD) - return __pgd_alloc(mm, PGD_ALLOCATION_ORDER); - - /* - * Now PAE kernel is not running as a Xen domain. We can allocate - * a 32-byte slab for pgd to save memory space. + * PTI and Xen need a whole page for the PAE PGD + * even though the hardware only needs 32 bytes. + * + * For simplicity, allocate a page for all users. */ - return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER); -} - -static inline void _pgd_free(struct mm_struct *mm, pgd_t *pgd) -{ - if (!SHARED_KERNEL_PMD) - __pgd_free(mm, pgd); - else - kmem_cache_free(pgd_cache, pgd); -} -#else - -static inline pgd_t *_pgd_alloc(struct mm_struct *mm) -{ return __pgd_alloc(mm, PGD_ALLOCATION_ORDER); } @@ -387,7 +334,6 @@ static inline void _pgd_free(struct mm_struct *mm, pgd_t *pgd) { __pgd_free(mm, pgd); } -#endif /* CONFIG_X86_PAE */ pgd_t *pgd_alloc(struct mm_struct *mm) { |