Experiment on usefuleness of cache coloring on ia32

@@ -9,4 +9,8 @@
 
 #define        L1_CACHE_ALIGN(x)       (((x)+(L1_CACHE_BYTES-1))&~(L1_CACHE_BYTES-1))
 
+/* L2 cache heuristics, only define if you want page coloring */
+#define        L2_CACHE_BYTES		64
+#define        L2_CACHE_SIZE		(512 * 1024)
+
 #endif

@@ -262,6 +262,8 @@ extern inline unsigned long get_free_pag
 	return page;
 }
 
+extern unsigned long get_colored_page(int gfp_mask, int *colorp);
+
 extern int low_on_memory;
 
 /* memory.c & swap.c*/

@@ -339,6 +339,7 @@ struct inode {
 	struct list_head	i_dentry;
 
 	unsigned long		i_ino;
+	unsigned int		i_color;
 	unsigned int		i_count;
 	kdev_t			i_dev;
 	umode_t			i_mode;

@@ -166,6 +166,7 @@ struct mm_struct {
 	pgd_t * pgd;
 	atomic_t count;
 	int map_count;				/* number of VMAs */
+	int color;
 	struct semaphore mmap_sem;
 	unsigned long context;
 	unsigned long start_code, end_code, start_data, end_data;

@@ -184,7 +185,7 @@ struct mm_struct {
 #define INIT_MM {					\
 		&init_mmap, NULL, NULL,			\
 		swapper_pg_dir, 			\
-		ATOMIC_INIT(1), 1,			\
+		ATOMIC_INIT(1), 1, 0,			\
 		MUTEX,					\
 		0,					\
 		0, 0, 0, 0,				\

@@ -87,6 +87,7 @@ EXPORT_SYMBOL(exit_sighand);
 
 /* internal kernel memory management */
 EXPORT_SYMBOL(__get_free_pages);
+EXPORT_SYMBOL(get_colored_page);
 EXPORT_SYMBOL(free_pages);
 EXPORT_SYMBOL(__free_page);
 EXPORT_SYMBOL(kmem_find_general_cachep);

@@ -253,7 +253,7 @@ static unsigned long try_to_read_ahead(s
 	offset &= PAGE_MASK;
 	switch (page_cache) {
 	case 0:
-		page_cache = __get_free_page(GFP_USER);
+		page_cache = get_colored_page(GFP_USER, &inode->i_color);
 		if (!page_cache)
 			break;
 	default:

@@ -675,7 +675,7 @@ no_cached_page:
 		 * page..
 		 */
 		if (!page_cache) {
-			page_cache = __get_free_page(GFP_USER);
+			page_cache = get_colored_page(GFP_USER, &inode->i_color);
 			/*
 			 * That could have slept, so go around to the
 			 * very beginning..

@@ -941,7 +941,7 @@ found_page:
 	 * extra page -- better to overlap the allocation with the I/O.
 	 */
 	if (no_share && !new_page) {
-		new_page = __get_free_page(GFP_USER);
+		new_page = get_colored_page(GFP_USER, &inode->i_color);
 		if (!new_page)
 			goto failure;
 	}

@@ -989,7 +989,7 @@ no_cached_page:
 		new_page = try_to_read_ahead(file, reada, new_page);
 
 	if (!new_page)
-		new_page = __get_free_page(GFP_USER);
+		new_page = get_colored_page(GFP_USER, &inode->i_color);
 	if (!new_page)
 		goto no_page;
 

@@ -1464,7 +1464,7 @@ generic_file_write(struct file *file, co
 		page = __find_page(inode, pgpos, *hash);
 		if (!page) {
 			if (!page_cache) {
-				page_cache = __get_free_page(GFP_USER);
+				page_cache = get_colored_page(GFP_USER, &inode->i_color);
 				if (page_cache)
 					continue;
 				status = -ENOMEM;

@@ -1535,7 +1535,7 @@ unsigned long get_cached_page(struct ino
 	if (!page) {
 		if (!new)
 			goto out;
-		page_cache = get_free_page(GFP_USER);
+		page_cache = get_colored_page(GFP_USER, &inode->i_color);
 		if (!page_cache)
 			goto out;
 		page = mem_map + MAP_NR(page_cache);

106 lines not on this page · raw message

@@ -808,7 +808,7 @@ static int do_anonymous_page(struct task
 {
 	pte_t entry = pte_wrprotect(mk_pte(ZERO_PAGE, vma->vm_page_prot));
 	if (write_access) {
-		unsigned long page = __get_free_page(GFP_USER);
+		unsigned long page = get_colored_page(GFP_USER, &vma->vm_mm->color);
 		if (!page)
 			return 0;
 		clear_page(page);