SLUB: i386 support
SLUB cannot run on i386 at this point because i386 uses the page->private and
page->index field of slab pages for the pgd cache.
Make SLUB run on i386 by replacing the pgd slab cache with a quicklist.
Limit the changes as much as possible. Leave the improvised linked list in place
etc etc. This has been working here for a couple of weeks now.
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 9a96c16..8d7c086 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -13,6 +13,7 @@
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <linux/module.h>
+#include <linux/quicklist.h>
#include <asm/system.h>
#include <asm/pgtable.h>
@@ -205,8 +206,6 @@
* against pageattr.c; it is the unique case in which a valid change
* of kernel pagetables can't be lazily synchronized by vmalloc faults.
* vmalloc faults work because attached pagetables are never freed.
- * The locking scheme was chosen on the basis of manfred's
- * recommendations and having no core impact whatsoever.
* -- wli
*/
DEFINE_SPINLOCK(pgd_lock);
@@ -232,9 +231,11 @@
set_page_private(next, (unsigned long)pprev);
}
+
+
#if (PTRS_PER_PMD == 1)
/* Non-PAE pgd constructor */
-void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+void pgd_ctor(void *pgd)
{
unsigned long flags;
@@ -256,7 +257,7 @@
}
#else /* PTRS_PER_PMD > 1 */
/* PAE pgd constructor */
-void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+void pgd_ctor(void *pgd)
{
/* PAE, kernel PMD may be shared */
@@ -275,11 +276,12 @@
}
#endif /* PTRS_PER_PMD */
-void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+void pgd_dtor(void *pgd)
{
unsigned long flags; /* can be called from interrupt context */
- BUG_ON(SHARED_KERNEL_PMD);
+ if (SHARED_KERNEL_PMD)
+ return;
paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
spin_lock_irqsave(&pgd_lock, flags);
@@ -321,7 +323,7 @@
pgd_t *pgd_alloc(struct mm_struct *mm)
{
int i;
- pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
+ pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
if (PTRS_PER_PMD == 1 || !pgd)
return pgd;
@@ -344,7 +346,7 @@
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
pmd_cache_free(pmd, i);
}
- kmem_cache_free(pgd_cache, pgd);
+ quicklist_free(0, pgd_dtor, pgd);
return NULL;
}
@@ -361,5 +363,11 @@
pmd_cache_free(pmd, i);
}
/* in the non-PAE case, free_pgtables() clears user pgd entries */
- kmem_cache_free(pgd_cache, pgd);
+ quicklist_free(0, pgd_dtor, pgd);
}
+
+void check_pgt_cache(void)
+{
+ quicklist_trim(0, pgd_dtor, 25, 16);
+}
+