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xtensa: use buddy allocator for PTE table

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At the moment xtensa uses slab allocator for PTE table.  It doesn't work
with enabled split page table lock: slab uses page->slab_cache and
page->first_page for its pages.  These fields share stroage with
page->ptl.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2013-11-14 14:31:50 -08:00 committed by Linus Torvalds
parent 01058e7076
commit f820e2805c
3 changed files with 13 additions and 30 deletions
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20
arch/xtensa/include/asm/pgalloc.h
View File

@ -38,14 +38,18 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
free_page((unsigned long)pgd); free_page((unsigned long)pgd);
} }
/* Use a slab cache for the pte pages (see also sparc64 implementation) */
extern struct kmem_cache *pgtable_cache;
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address) unsigned long address)
{ {
return kmem_cache_alloc(pgtable_cache, GFP_KERNEL|__GFP_REPEAT); pte_t *ptep;
int i;
ptep = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
if (!ptep)
return NULL;
for (i = 0; i < 1024; i++)
pte_clear(NULL, 0, ptep + i);
return ptep;
} }
static inline pgtable_t pte_alloc_one(struct mm_struct *mm, static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
@ -59,7 +63,7 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
return NULL; return NULL;
page = virt_to_page(pte); page = virt_to_page(pte);
if (!pgtable_page_ctor(page)) { if (!pgtable_page_ctor(page)) {
kmem_cache_free(pgtable_cache, pte); __free_page(page);
return NULL; return NULL;
} }
return page; return page;
@ -67,13 +71,13 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{ {
kmem_cache_free(pgtable_cache, pte); free_page((unsigned long)pte);
} }
static inline void pte_free(struct mm_struct *mm, pgtable_t pte) static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
{ {
pgtable_page_dtor(pte); pgtable_page_dtor(pte);
kmem_cache_free(pgtable_cache, page_address(pte)); __free_page(pte);
} }
#define pmd_pgtable(pmd) pmd_page(pmd) #define pmd_pgtable(pmd) pmd_page(pmd)

3
arch/xtensa/include/asm/pgtable.h
View File

@ -220,12 +220,11 @@ extern unsigned long empty_zero_page[1024];
#ifdef CONFIG_MMU #ifdef CONFIG_MMU
extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)]; extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)];
extern void paging_init(void); extern void paging_init(void);
extern void pgtable_cache_init(void);
#else #else
# define swapper_pg_dir NULL # define swapper_pg_dir NULL
static inline void paging_init(void) { } static inline void paging_init(void) { }
static inline void pgtable_cache_init(void) { }
#endif #endif
static inline void pgtable_cache_init(void) { }
/* /*
* The pmd contains the kernel virtual address of the pte page. * The pmd contains the kernel virtual address of the pte page.

20
arch/xtensa/mm/mmu.c
View File

@ -50,23 +50,3 @@ void __init init_mmu(void)
*/ */
set_ptevaddr_register(PGTABLE_START); set_ptevaddr_register(PGTABLE_START);
} }
struct kmem_cache *pgtable_cache __read_mostly;
static void pgd_ctor(void *addr)
{
pte_t *ptep = (pte_t *)addr;
int i;
for (i = 0; i < 1024; i++, ptep++)
pte_clear(NULL, 0, ptep);
}
void __init pgtable_cache_init(void)
{
pgtable_cache = kmem_cache_create("pgd",
PAGE_SIZE, PAGE_SIZE,
SLAB_HWCACHE_ALIGN,
pgd_ctor);
}