[SPARC64]: Kill pgtable quicklists and use SLAB.

Taking a nod from the powerpc port.

With the per-cpu caching of both the page allocator and SLAB, the
pgtable quicklist scheme becomes relatively silly and primitive.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/sparc64_ksyms.c

@@ -241,10 +241,6 @@ EXPORT_SYMBOL(verify_compat_iovec);
 #endif
 
 EXPORT_SYMBOL(dump_fpu);
-EXPORT_SYMBOL(pte_alloc_one_kernel);
-#ifndef CONFIG_SMP
-EXPORT_SYMBOL(pgt_quicklists);
-#endif
 EXPORT_SYMBOL(put_fs_struct);
 
 /* math-emu wants this */

arch/sparc64/mm/init.c

@@ -141,26 +141,25 @@ unsigned long sparc64_kern_sec_context __read_mostly;
 
 int bigkernel = 0;
 
-/* XXX Tune this... */
-#define PGT_CACHE_LOW	25
-#define PGT_CACHE_HIGH	50
+kmem_cache_t *pgtable_cache __read_mostly;
 
-#ifndef CONFIG_SMP
-struct pgtable_cache_struct pgt_quicklists;
-#endif
+static void zero_ctor(void *addr, kmem_cache_t *cache, unsigned long flags)
+{
+	clear_page(addr);
+}
 
-void check_pgt_cache(void)
+void pgtable_cache_init(void)
 {
-	preempt_disable();
-	if (pgtable_cache_size > PGT_CACHE_HIGH) {
-		do {
-			if (pgd_quicklist)
-				free_pgd_slow(get_pgd_fast());
-			if (pte_quicklist)
-				free_pte_slow(pte_alloc_one_fast());
-		} while (pgtable_cache_size > PGT_CACHE_LOW);
+	pgtable_cache = kmem_cache_create("pgtable_cache",
+					  PAGE_SIZE, PAGE_SIZE,
+					  SLAB_HWCACHE_ALIGN |
+					  SLAB_MUST_HWCACHE_ALIGN,
+					  zero_ctor,
+					  NULL);
+	if (!pgtable_cache) {
+		prom_printf("pgtable_cache_init(): Could not create!\n");
+		prom_halt();
 	}
-	preempt_enable();
 }
 
 #ifdef CONFIG_DEBUG_DCFLUSH
@@ -340,7 +339,6 @@ void show_mem(void)
 	       nr_swap_pages << (PAGE_SHIFT-10));
 	printk("%ld pages of RAM\n", num_physpages);
 	printk("%d free pages\n", nr_free_pages());
-	printk("%d pages in page table cache\n",pgtable_cache_size);
 }
 
 void mmu_info(struct seq_file *m)

include/asm-sparc64/cpudata.h

@@ -17,14 +17,7 @@ typedef struct {
 	unsigned long	clock_tick;	/* %tick's per second */
 	unsigned long	udelay_val;
 
-	/* Dcache line 2 */
-	unsigned int	pgcache_size;
-	unsigned int	__pad1;
-	unsigned long	*pte_cache;
-	unsigned long	*pgd_cache;
-	unsigned long	__pad2;
-
-	/* Dcache line 3, rarely used */
+	/* Dcache line 2, rarely used */
 	unsigned int	dcache_size;
 	unsigned int	dcache_line_size;
 	unsigned int	icache_size;

include/asm-sparc64/pgalloc.h

@@ -6,6 +6,7 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/slab.h>
 
 #include <asm/spitfire.h>
 #include <asm/cpudata.h>
@@ -13,164 +14,59 @@
 #include <asm/page.h>
 
 /* Page table allocation/freeing. */
-#ifdef CONFIG_SMP
-/* Sliiiicck */
-#define pgt_quicklists	local_cpu_data()
-#else
-extern struct pgtable_cache_struct {
-	unsigned long *pgd_cache;
-	unsigned long *pte_cache;
-	unsigned int pgcache_size;
-} pgt_quicklists;
-#endif
-#define pgd_quicklist		(pgt_quicklists.pgd_cache)
-#define pte_quicklist		(pgt_quicklists.pte_cache)
-#define pgtable_cache_size	(pgt_quicklists.pgcache_size)
+extern kmem_cache_t *pgtable_cache;
 
-static inline void free_pgd_fast(pgd_t *pgd)
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	preempt_disable();
-	*(unsigned long *)pgd = (unsigned long) pgd_quicklist;
-	pgd_quicklist = (unsigned long *) pgd;
-	pgtable_cache_size++;
-	preempt_enable();
+	return kmem_cache_alloc(pgtable_cache, GFP_KERNEL);
 }
 
-static inline pgd_t *get_pgd_fast(void)
+static inline void pgd_free(pgd_t *pgd)
 {
-	unsigned long *ret;
-
-	preempt_disable();
-	if((ret = pgd_quicklist) != NULL) {
-		pgd_quicklist = (unsigned long *)(*ret);
-		ret[0] = 0;
-		pgtable_cache_size--;
-		preempt_enable();
-	} else {
-		preempt_enable();
-		ret = (unsigned long *) __get_free_page(GFP_KERNEL|__GFP_REPEAT);
-		if(ret)
-			memset(ret, 0, PAGE_SIZE);
-	}
-	return (pgd_t *)ret;
-}
-
-static inline void free_pgd_slow(pgd_t *pgd)
-{
-	free_page((unsigned long)pgd);
+	kmem_cache_free(pgtable_cache, pgd);
 }
 
 #define pud_populate(MM, PUD, PMD)	pud_set(PUD, PMD)
 
-static inline pmd_t *pmd_alloc_one_fast(void)
-{
-	unsigned long *ret;
-
-	preempt_disable();
-	ret = (unsigned long *) pte_quicklist;
-	if (likely(ret)) {
-		pte_quicklist = (unsigned long *)(*ret);
-		ret[0] = 0;
-		pgtable_cache_size--;
-	}
-	preempt_enable();
-
-	return (pmd_t *) ret;
-}
-
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
-{
-	pmd_t *pmd;
-
-	pmd = pmd_alloc_one_fast();
-	if (unlikely(!pmd)) {
-		pmd = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-		if (pmd)
-			memset(pmd, 0, PAGE_SIZE);
-	}
-	return pmd;
-}
-
-static inline void free_pmd_fast(pmd_t *pmd)
-{
-	preempt_disable();
-	*(unsigned long *)pmd = (unsigned long) pte_quicklist;
-	pte_quicklist = (unsigned long *) pmd;
-	pgtable_cache_size++;
-	preempt_enable();
-}
-
-static inline void free_pmd_slow(pmd_t *pmd)
-{
-	free_page((unsigned long)pmd);
-}
-
-#define pmd_populate_kernel(MM, PMD, PTE)	pmd_set(PMD, PTE)
-#define pmd_populate(MM,PMD,PTE_PAGE)		\
-	pmd_populate_kernel(MM,PMD,page_address(PTE_PAGE))
-
-static inline pte_t *pte_alloc_one_fast(void)
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	unsigned long *ret;
-
-	preempt_disable();
-	ret = (unsigned long *) pte_quicklist;
-	if (likely(ret)) {
-		pte_quicklist = (unsigned long *)(*ret);
-		ret[0] = 0;
-		pgtable_cache_size--;
-	}
-	preempt_enable();
-
-	return (pte_t *) ret;
+	return kmem_cache_alloc(pgtable_cache,
+				GFP_KERNEL|__GFP_REPEAT);
 }
 
-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+static inline void pmd_free(pmd_t *pmd)
 {
-	pte_t *ptep = pte_alloc_one_fast();
-
-	if (likely(ptep))
-		return ptep;
-
-	return (pte_t *) get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+	kmem_cache_free(pgtable_cache, pmd);
 }
 
-static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long addr)
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
+					  unsigned long address)
 {
-	pte_t *pte = pte_alloc_one_fast();
-
-	if (likely(pte))
-		return virt_to_page(pte);
-
-	return alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
+	return kmem_cache_alloc(pgtable_cache,
+				GFP_KERNEL|__GFP_REPEAT);
 }
 
-static inline void free_pte_fast(pte_t *pte)
+static inline struct page *pte_alloc_one(struct mm_struct *mm,
+					 unsigned long address)
 {
-	preempt_disable();
-	*(unsigned long *)pte = (unsigned long) pte_quicklist;
-	pte_quicklist = (unsigned long *) pte;
-	pgtable_cache_size++;
-	preempt_enable();
+	return virt_to_page(pte_alloc_one_kernel(mm, address));
 }
-
-static inline void free_pte_slow(pte_t *pte)
-{
-	free_page((unsigned long) pte);
-}
-
+		
 static inline void pte_free_kernel(pte_t *pte)
 {
-	free_pte_fast(pte);
+	kmem_cache_free(pgtable_cache, pte);
 }
 
 static inline void pte_free(struct page *ptepage)
 {
-	free_pte_fast(page_address(ptepage));
+	pte_free_kernel(page_address(ptepage));
 }
 
-#define pmd_free(pmd)		free_pmd_fast(pmd)
-#define pgd_free(pgd)		free_pgd_fast(pgd)
-#define pgd_alloc(mm)		get_pgd_fast()
+
+#define pmd_populate_kernel(MM, PMD, PTE)	pmd_set(PMD, PTE)
+#define pmd_populate(MM,PMD,PTE_PAGE)		\
+	pmd_populate_kernel(MM,PMD,page_address(PTE_PAGE))
+
+#define check_pgt_cache()	do { } while (0)
 
 #endif /* _SPARC64_PGALLOC_H */

include/asm-sparc64/pgtable.h

@@ -432,12 +432,7 @@ extern unsigned long get_fb_unmapped_area(struct file *filp, unsigned long,
 					  unsigned long);
 #define HAVE_ARCH_FB_UNMAPPED_AREA
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
-extern void check_pgt_cache(void);
+extern void pgtable_cache_init(void);
 
 #endif /* !(__ASSEMBLY__) */