Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 (bb193c98) · Commits · 戴 / test

Documentation/vm/slub.txt

+10 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,8 @@ Possible debug options are
		P Poisoning (object and padding)
		U User tracking (free and alloc)
		T Trace (please only use on single slabs)
		O Switch debugging off for caches that would have
		caused higher minimum slab orders
		- Switch all debugging off (useful if the kernel is
		configured with CONFIG_SLUB_DEBUG_ON)

		@@ -59,6 +61,14 @@ to the dentry cache with

		slub_debug=F,dentry

		Debugging options may require the minimum possible slab order to increase as
		a result of storing the metadata (for example, caches with PAGE_SIZE object
		sizes). This has a higher liklihood of resulting in slab allocation errors
		in low memory situations or if there's high fragmentation of memory. To
		switch off debugging for such caches by default, use

		slub_debug=O

		In case you forgot to enable debugging on the kernel command line: It is
		possible to enable debugging manually when the kernel is up. Look at the
		contents of:

include/linux/slob_def.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -34,9 +34,4 @@ static __always_inline void *__kmalloc(size_t size, gfp_t flags)
		return kmalloc(size, flags);
		}

		static inline void kmem_cache_init_late(void)
		{
		/* Nothing to do */
		}

		#endif /* __LINUX_SLOB_DEF_H */

include/linux/slub_def.h

+2 −6

Original line number	Diff line number	Diff line
		@@ -153,12 +153,10 @@ static __always_inline int kmalloc_index(size_t size)
		if (size <= KMALLOC_MIN_SIZE)
		return KMALLOC_SHIFT_LOW;

		#if KMALLOC_MIN_SIZE <= 64
		if (size > 64 && size <= 96)
		if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
		return 1;
		if (size > 128 && size <= 192)
		if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
		return 2;
		#endif
		if (size <= 8) return 3;
		if (size <= 16) return 4;
		if (size <= 32) return 5;
		@@ -304,6 +302,4 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
		}
		#endif

		void __init kmem_cache_init_late(void);

		#endif /* _LINUX_SLUB_DEF_H */

mm/slob.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -692,3 +692,8 @@ void __init kmem_cache_init(void)
		{
		slob_ready = 1;
		}

		void __init kmem_cache_init_late(void)
		{
		/* Nothing to do */
		}

mm/slub.c

+68 −14

Original line number	Diff line number	Diff line
		@@ -140,6 +140,13 @@
		#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE \| SLAB_RED_ZONE \| \
		SLAB_POISON \| SLAB_STORE_USER)

		/*
		* Debugging flags that require metadata to be stored in the slab. These get
		* disabled when slub_debug=O is used and a cache's min order increases with
		* metadata.
		*/
		#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE \| SLAB_POISON \| SLAB_STORE_USER)

		/*
		* Set of flags that will prevent slab merging
		*/
		@@ -325,6 +332,7 @@ static int slub_debug;
		#endif

		static char *slub_debug_slabs;
		static int disable_higher_order_debug;

		/*
		* Object debugging
		@@ -646,7 +654,7 @@ static int slab_pad_check(struct kmem_cache s, struct page page)
		slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
		print_section("Padding", end - remainder, remainder);

		restore_bytes(s, "slab padding", POISON_INUSE, start, end);
		restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
		return 0;
		}

		@@ -976,6 +984,15 @@ static int __init setup_slub_debug(char *str)
		*/
		goto check_slabs;

		if (tolower(*str) == 'o') {
		/*
		* Avoid enabling debugging on caches if its minimum order
		* would increase as a result.
		*/
		disable_higher_order_debug = 1;
		goto out;
		}

		slub_debug = 0;
		if (*str == '-')
		/*
		@@ -1026,7 +1043,7 @@ static unsigned long kmem_cache_flags(unsigned long objsize,
		* Enable debugging if selected on the kernel commandline.
		*/
		if (slub_debug && (!slub_debug_slabs \|\|
		strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
		!strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
		flags \|= slub_debug;

		return flags;
		@@ -1109,8 +1126,7 @@ static struct page allocate_slab(struct kmem_cache s, gfp_t flags, int node)
		}

		if (kmemcheck_enabled
		&& !(s->flags & (SLAB_NOTRACK \| DEBUG_DEFAULT_FLAGS)))
		{
		&& !(s->flags & (SLAB_NOTRACK \| DEBUG_DEFAULT_FLAGS))) {
		int pages = 1 << oo_order(oo);

		kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
		@@ -1560,6 +1576,10 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
		"default order: %d, min order: %d\n", s->name, s->objsize,
		s->size, oo_order(s->oo), oo_order(s->min));

		if (oo_order(s->min) > get_order(s->objsize))
		printk(KERN_WARNING " %s debugging increased min order, use "
		"slub_debug=O to disable.\n", s->name);

		for_each_online_node(node) {
		struct kmem_cache_node *n = get_node(s, node);
		unsigned long nr_slabs;
		@@ -2400,6 +2420,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
		* on bootup.
		*/
		align = calculate_alignment(flags, align, s->objsize);
		s->align = align;

		/*
		* SLUB stores one object immediately after another beginning from
		@@ -2452,6 +2473,18 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,

		if (!calculate_sizes(s, -1))
		goto error;
		if (disable_higher_order_debug) {
		/*
		* Disable debugging flags that store metadata if the min slab
		* order increased.
		*/
		if (get_order(s->size) > get_order(s->objsize)) {
		s->flags &= ~DEBUG_METADATA_FLAGS;
		s->offset = 0;
		if (!calculate_sizes(s, -1))
		goto error;
		}
		}

		/*
		* The larger the object size is, the more pages we want on the partial
		@@ -2790,6 +2823,11 @@ static s8 size_index[24] = {
		2 /* 192 */
		};

		static inline int size_index_elem(size_t bytes)
		{
		return (bytes - 1) / 8;
		}

		static struct kmem_cache *get_slab(size_t size, gfp_t flags)
		{
		int index;
		@@ -2798,7 +2836,7 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
		if (!size)
		return ZERO_SIZE_PTR;

		index = size_index[(size - 1) / 8];
		index = size_index[size_index_elem(size)];
		} else
		index = fls(size - 1);

		@@ -3156,10 +3194,12 @@ void __init kmem_cache_init(void)
		slab_state = PARTIAL;

		/* Caches that are not of the two-to-the-power-of size */
		if (KMALLOC_MIN_SIZE <= 64) {
		if (KMALLOC_MIN_SIZE <= 32) {
		create_kmalloc_cache(&kmalloc_caches[1],
		"kmalloc-96", 96, GFP_NOWAIT);
		caches++;
		}
		if (KMALLOC_MIN_SIZE <= 64) {
		create_kmalloc_cache(&kmalloc_caches[2],
		"kmalloc-192", 192, GFP_NOWAIT);
		caches++;
		@@ -3186,17 +3226,28 @@ void __init kmem_cache_init(void)
		BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 \|\|
		(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));

		for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
		size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
		for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
		int elem = size_index_elem(i);
		if (elem >= ARRAY_SIZE(size_index))
		break;
		size_index[elem] = KMALLOC_SHIFT_LOW;
		}

		if (KMALLOC_MIN_SIZE == 128) {
		if (KMALLOC_MIN_SIZE == 64) {
		/*
		* The 96 byte size cache is not used if the alignment
		* is 64 byte.
		*/
		for (i = 64 + 8; i <= 96; i += 8)
		size_index[size_index_elem(i)] = 7;
		} else if (KMALLOC_MIN_SIZE == 128) {
		/*
		* The 192 byte sized cache is not used if the alignment
		* is 128 byte. Redirect kmalloc to use the 256 byte cache
		* instead.
		*/
		for (i = 128 + 8; i <= 192; i += 8)
		size_index[(i - 1) / 8] = 8;
		size_index[size_index_elem(i)] = 8;
		}

		slab_state = UP;
		@@ -4543,8 +4594,11 @@ static int sysfs_slab_add(struct kmem_cache *s)
		}

		err = sysfs_create_group(&s->kobj, &slab_attr_group);
		if (err)
		if (err) {
		kobject_del(&s->kobj);
		kobject_put(&s->kobj);
		return err;
		}
		kobject_uevent(&s->kobj, KOBJ_ADD);
		if (!unmergeable) {
		/* Setup first alias */
		@@ -4726,7 +4780,7 @@ static const struct file_operations proc_slabinfo_operations = {

		static int __init slab_proc_init(void)
		{
		proc_create("slabinfo",S_IWUSR\|S_IRUGO,NULL,&proc_slabinfo_operations);
		proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
		return 0;
		}
		module_init(slab_proc_init);

Admin message