[POWERPC] Don't use SLAB/SLUB for PTE pages
The SLUB allocator relies on struct page fields first_page and slab,
overwritten by ptl when SPLIT_PTLOCK: so the SLUB allocator cannot then
be used for the lowest level of pagetable pages. This was obstructing
SLUB on PowerPC, which uses kmem_caches for its pagetables. So convert
its pte level to use normal gfp pages (whereas pmd, pud and 64k-page pgd
want partpages, so continue to use kmem_caches for pmd, pud and pgd).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/pgalloc-64.h b/include/asm-powerpc/pgalloc-64.h
index 30b50cf..d9a3a8c 100644
--- a/include/asm-powerpc/pgalloc-64.h
+++ b/include/asm-powerpc/pgalloc-64.h
@@ -14,18 +14,11 @@
extern struct kmem_cache *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
+#define PGD_CACHE_NUM 0
+#define PUD_CACHE_NUM 1
+#define PMD_CACHE_NUM 1
+#define HUGEPTE_CACHE_NUM 2
+#define PTE_NONCACHE_NUM 3 /* from GFP rather than kmem_cache */
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
@@ -91,8 +84,7 @@
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);
+ return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
}
static inline struct page *pte_alloc_one(struct mm_struct *mm,
@@ -103,12 +95,12 @@
static inline void pte_free_kernel(pte_t *pte)
{
- kmem_cache_free(pgtable_cache[PTE_CACHE_NUM], pte);
+ free_page((unsigned long)pte);
}
static inline void pte_free(struct page *ptepage)
{
- pte_free_kernel(page_address(ptepage));
+ __free_page(ptepage);
}
#define PGF_CACHENUM_MASK 0x3
@@ -130,14 +122,17 @@
void *p = (void *)(pgf.val & ~PGF_CACHENUM_MASK);
int cachenum = pgf.val & PGF_CACHENUM_MASK;
- kmem_cache_free(pgtable_cache[cachenum], p);
+ if (cachenum == PTE_NONCACHE_NUM)
+ free_page((unsigned long)p);
+ else
+ 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))
+ PTE_NONCACHE_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))