kernel-ark/include/asm-powerpc/pgalloc.h
David Gibson f10a04c034 [PATCH] powerpc: Fix pagetable bloat for hugepages
At present, ARCH=powerpc kernels can waste considerable space in
pagetables when making large hugepage mappings.  Hugepage PTEs go in
PMD pages, but each PMD page maps 256M and so contains only 16
hugepage PTEs (128 bytes of data), but takes up a 1024 byte
allocation.  With CONFIG_PPC_64K_PAGES enabled (64k base page size),
the situation is worse.  Now hugepage PTEs are at the PTE page level
(also mapping 256M), so we store 16 hugepage PTEs in a 64k allocation.

The PowerPC MMU already means that any 256M region is either all
hugepage, or all normal pages.  Thus, with some care, we can use a
different allocation for the hugepage PTE tables and only allocate the
128 bytes necessary.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-28 15:02:51 +10:00

161 lines
3.9 KiB
C

#ifndef _ASM_POWERPC_PGALLOC_H
#define _ASM_POWERPC_PGALLOC_H
#ifdef __KERNEL__
#ifndef CONFIG_PPC64
#include <asm-ppc/pgalloc.h>
#else
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/cpumask.h>
#include <linux/percpu.h>
extern kmem_cache_t *pgtable_cache[];
#ifdef CONFIG_PPC_64K_PAGES
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 1
#define PGD_CACHE_NUM 2
#define HUGEPTE_CACHE_NUM 3
#else
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 1
#define PUD_CACHE_NUM 1
#define PGD_CACHE_NUM 0
#define HUGEPTE_CACHE_NUM 2
#endif
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
return kmem_cache_alloc(pgtable_cache[PGD_CACHE_NUM], GFP_KERNEL);
}
static inline void pgd_free(pgd_t *pgd)
{
kmem_cache_free(pgtable_cache[PGD_CACHE_NUM], pgd);
}
#ifndef CONFIG_PPC_64K_PAGES
#define pgd_populate(MM, PGD, PUD) pgd_set(PGD, PUD)
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
return kmem_cache_alloc(pgtable_cache[PUD_CACHE_NUM],
GFP_KERNEL|__GFP_REPEAT);
}
static inline void pud_free(pud_t *pud)
{
kmem_cache_free(pgtable_cache[PUD_CACHE_NUM], pud);
}
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
pud_set(pud, (unsigned long)pmd);
}
#define pmd_populate(mm, pmd, pte_page) \
pmd_populate_kernel(mm, pmd, page_address(pte_page))
#define pmd_populate_kernel(mm, pmd, pte) pmd_set(pmd, (unsigned long)(pte))
#else /* CONFIG_PPC_64K_PAGES */
#define pud_populate(mm, pud, pmd) pud_set(pud, (unsigned long)pmd)
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
pmd_set(pmd, (unsigned long)pte);
}
#define pmd_populate(mm, pmd, pte_page) \
pmd_populate_kernel(mm, pmd, page_address(pte_page))
#endif /* CONFIG_PPC_64K_PAGES */
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
return kmem_cache_alloc(pgtable_cache[PMD_CACHE_NUM],
GFP_KERNEL|__GFP_REPEAT);
}
static inline void pmd_free(pmd_t *pmd)
{
kmem_cache_free(pgtable_cache[PMD_CACHE_NUM], pmd);
}
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
return kmem_cache_alloc(pgtable_cache[PTE_CACHE_NUM],
GFP_KERNEL|__GFP_REPEAT);
}
static inline struct page *pte_alloc_one(struct mm_struct *mm,
unsigned long address)
{
return virt_to_page(pte_alloc_one_kernel(mm, address));
}
static inline void pte_free_kernel(pte_t *pte)
{
kmem_cache_free(pgtable_cache[PTE_CACHE_NUM], pte);
}
static inline void pte_free(struct page *ptepage)
{
pte_free_kernel(page_address(ptepage));
}
#define PGF_CACHENUM_MASK 0xf
typedef struct pgtable_free {
unsigned long val;
} pgtable_free_t;
static inline pgtable_free_t pgtable_free_cache(void *p, int cachenum,
unsigned long mask)
{
BUG_ON(cachenum > PGF_CACHENUM_MASK);
return (pgtable_free_t){.val = ((unsigned long) p & ~mask) | cachenum};
}
static inline void pgtable_free(pgtable_free_t pgf)
{
void *p = (void *)(pgf.val & ~PGF_CACHENUM_MASK);
int cachenum = pgf.val & PGF_CACHENUM_MASK;
kmem_cache_free(pgtable_cache[cachenum], p);
}
extern void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf);
#define __pte_free_tlb(tlb, ptepage) \
pgtable_free_tlb(tlb, pgtable_free_cache(page_address(ptepage), \
PTE_CACHE_NUM, PTE_TABLE_SIZE-1))
#define __pmd_free_tlb(tlb, pmd) \
pgtable_free_tlb(tlb, pgtable_free_cache(pmd, \
PMD_CACHE_NUM, PMD_TABLE_SIZE-1))
#ifndef CONFIG_PPC_64K_PAGES
#define __pud_free_tlb(tlb, pud) \
pgtable_free_tlb(tlb, pgtable_free_cache(pud, \
PUD_CACHE_NUM, PUD_TABLE_SIZE-1))
#endif /* CONFIG_PPC_64K_PAGES */
#define check_pgt_cache() do { } while (0)
#endif /* CONFIG_PPC64 */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_PGALLOC_H */