powerpc/THP: Double the PMD table size for THP

THP code does PTE page allocation along with large page request and deposit them
for later use. This is to ensure that we won't have any failures when we split
hugepages to regular pages.

On powerpc we want to use the deposited PTE page for storing hash pte slot and
secondary bit information for the HPTEs. We use the second half
of the pmd table to save the deposted PTE page.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Aneesh Kumar K.V 2013-06-20 14:30:14 +05:30 committed by Benjamin Herrenschmidt
parent db3d853490
commit f940f52898
4 changed files with 16 additions and 8 deletions

View File

@ -221,17 +221,17 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
return kmem_cache_alloc(PGT_CACHE(PMD_INDEX_SIZE),
return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
GFP_KERNEL|__GFP_REPEAT);
}
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
kmem_cache_free(PGT_CACHE(PMD_INDEX_SIZE), pmd);
kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
}
#define __pmd_free_tlb(tlb, pmd, addr) \
pgtable_free_tlb(tlb, pmd, PMD_INDEX_SIZE)
pgtable_free_tlb(tlb, pmd, PMD_CACHE_INDEX)
#ifndef CONFIG_PPC_64K_PAGES
#define __pud_free_tlb(tlb, pud, addr) \
pgtable_free_tlb(tlb, pud, PUD_INDEX_SIZE)

View File

@ -33,7 +33,8 @@
#define PGDIR_MASK (~(PGDIR_SIZE-1))
/* Bits to mask out from a PMD to get to the PTE page */
#define PMD_MASKED_BITS 0x1ff
/* PMDs point to PTE table fragments which are 4K aligned. */
#define PMD_MASKED_BITS 0xfff
/* Bits to mask out from a PGD/PUD to get to the PMD page */
#define PUD_MASKED_BITS 0x1ff

View File

@ -20,7 +20,11 @@
PUD_INDEX_SIZE + PGD_INDEX_SIZE + PAGE_SHIFT)
#define PGTABLE_RANGE (ASM_CONST(1) << PGTABLE_EADDR_SIZE)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define PMD_CACHE_INDEX (PMD_INDEX_SIZE + 1)
#else
#define PMD_CACHE_INDEX PMD_INDEX_SIZE
#endif
/*
* Define the address range of the kernel non-linear virtual area
*/

View File

@ -88,7 +88,11 @@ static void pgd_ctor(void *addr)
static void pmd_ctor(void *addr)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
memset(addr, 0, PMD_TABLE_SIZE * 2);
#else
memset(addr, 0, PMD_TABLE_SIZE);
#endif
}
struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
@ -137,10 +141,9 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
void pgtable_cache_init(void)
{
pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor);
if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE))
pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX))
panic("Couldn't allocate pgtable caches");
/* In all current configs, when the PUD index exists it's the
* same size as either the pgd or pmd index. Verify that the
* initialization above has also created a PUD cache. This