[PATCH] powerpc: 64k pages pmd alloc fix

This patch makes the kernel use a different kmem cache for PMD pages
as they are smaller than PTE pages. Avoids waste of memory.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Benjamin Herrenschmidt 2005-11-10 14:53:16 +11:00 committed by Paul Mackerras
parent e1449ed956
commit 87655ff268
2 changed files with 16 additions and 6 deletions

View file

@ -20,6 +20,8 @@
*
*/
#undef DEBUG
#include <linux/config.h>
#include <linux/signal.h>
#include <linux/sched.h>
@ -64,6 +66,12 @@
#include <asm/vdso.h>
#include <asm/imalloc.h>
#ifdef DEBUG
#define DBG(fmt...) printk(fmt)
#else
#define DBG(fmt...)
#endif
#if PGTABLE_RANGE > USER_VSID_RANGE
#warning Limited user VSID range means pagetable space is wasted
#endif
@ -188,14 +196,14 @@ static void zero_ctor(void *addr, kmem_cache_t *cache, unsigned long flags)
}
#ifdef CONFIG_PPC_64K_PAGES
static const int pgtable_cache_size[2] = {
PTE_TABLE_SIZE, PGD_TABLE_SIZE
static const unsigned int pgtable_cache_size[3] = {
PTE_TABLE_SIZE, PMD_TABLE_SIZE, PGD_TABLE_SIZE
};
static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = {
"pte_pmd_cache", "pgd_cache",
"pte_pmd_cache", "pmd_cache", "pgd_cache",
};
#else
static const int pgtable_cache_size[2] = {
static const unsigned int pgtable_cache_size[2] = {
PTE_TABLE_SIZE, PMD_TABLE_SIZE
};
static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = {
@ -213,6 +221,8 @@ void pgtable_cache_init(void)
int size = pgtable_cache_size[i];
const char *name = pgtable_cache_name[i];
DBG("Allocating page table cache %s (#%d) "
"for size: %08x...\n", name, i, size);
pgtable_cache[i] = kmem_cache_create(name,
size, size,
SLAB_HWCACHE_ALIGN |

View file

@ -10,8 +10,8 @@ extern kmem_cache_t *pgtable_cache[];
#ifdef CONFIG_PPC_64K_PAGES
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 0
#define PGD_CACHE_NUM 1
#define PMD_CACHE_NUM 1
#define PGD_CACHE_NUM 2
#else
#define PTE_CACHE_NUM 0
#define PMD_CACHE_NUM 1