Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux (6296e5d3) · Commits · 戴 / test

Documentation/kernel-parameters.txt

+6 −0

Original line number	Diff line number	Diff line
		@@ -2395,6 +2395,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.

		slram= [HW,MTD]

		slab_max_order= [MM, SLAB]
		Determines the maximum allowed order for slabs.
		A high setting may cause OOMs due to memory
		fragmentation. Defaults to 1 for systems with
		more than 32MB of RAM, 0 otherwise.

		slub_debug[=options[,slabs]] [MM, SLUB]
		Enabling slub_debug allows one to determine the
		culprit if slab objects become corrupted. Enabling

Documentation/vm/slub.txt

+1 −1

Original line number	Diff line number	Diff line
		@@ -117,7 +117,7 @@ can be influenced by kernel parameters:

		slub_min_objects=x (default 4)
		slub_min_order=x (default 0)
		slub_max_order=x (default 1)
		slub_max_order=x (default 3 (PAGE_ALLOC_COSTLY_ORDER))

		slub_min_objects allows to specify how many objects must at least fit
		into one slab in order for the allocation order to be acceptable.

mm/slab.c

+27 −12

Original line number	Diff line number	Diff line
		@@ -481,11 +481,13 @@ EXPORT_SYMBOL(slab_buffer_size);
		#endif

		/*
		* Do not go above this order unless 0 objects fit into the slab.
		* Do not go above this order unless 0 objects fit into the slab or
		* overridden on the command line.
		*/
		#define BREAK_GFP_ORDER_HI 1
		#define BREAK_GFP_ORDER_LO 0
		static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
		#define SLAB_MAX_ORDER_HI 1
		#define SLAB_MAX_ORDER_LO 0
		static int slab_max_order = SLAB_MAX_ORDER_LO;
		static bool slab_max_order_set __initdata;

		/*
		* Functions for storing/retrieving the cachep and or slab from the page
		@@ -854,6 +856,17 @@ static int __init noaliencache_setup(char *s)
		}
		__setup("noaliencache", noaliencache_setup);

		static int __init slab_max_order_setup(char *str)
		{
		get_option(&str, &slab_max_order);
		slab_max_order = slab_max_order < 0 ? 0 :
		min(slab_max_order, MAX_ORDER - 1);
		slab_max_order_set = true;

		return 1;
		}
		__setup("slab_max_order=", slab_max_order_setup);

		#ifdef CONFIG_NUMA
		/*
		* Special reaping functions for NUMA systems called from cache_reap().
		@@ -1502,10 +1515,11 @@ void __init kmem_cache_init(void)

		/*
		* Fragmentation resistance on low memory - only use bigger
		* page orders on machines with more than 32MB of memory.
		* page orders on machines with more than 32MB of memory if
		* not overridden on the command line.
		*/
		if (totalram_pages > (32 << 20) >> PAGE_SHIFT)
		slab_break_gfp_order = BREAK_GFP_ORDER_HI;
		if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT)
		slab_max_order = SLAB_MAX_ORDER_HI;

		/* Bootstrap is tricky, because several objects are allocated
		* from caches that do not exist yet:
		@@ -1932,8 +1946,8 @@ static void check_poison_obj(struct kmem_cache cachep, void objp)
		/* Print header */
		if (lines == 0) {
		printk(KERN_ERR
		"Slab corruption: %s start=%p, len=%d\n",
		cachep->name, realobj, size);
		"Slab corruption (%s): %s start=%p, len=%d\n",
		print_tainted(), cachep->name, realobj, size);
		print_objinfo(cachep, objp, 0);
		}
		/* Hexdump the affected line */
		@@ -2117,7 +2131,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
		* Large number of objects is good, but very large slabs are
		* currently bad for the gfp()s.
		*/
		if (gfporder >= slab_break_gfp_order)
		if (gfporder >= slab_max_order)
		break;

		/*
		@@ -3042,8 +3056,9 @@ static void check_slabp(struct kmem_cache cachep, struct slab slabp)
		if (entries != cachep->num - slabp->inuse) {
		bad:
		printk(KERN_ERR "slab: Internal list corruption detected in "
		"cache '%s'(%d), slabp %p(%d). Hexdump:\n",
		cachep->name, cachep->num, slabp, slabp->inuse);
		"cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n",
		cachep->name, cachep->num, slabp, slabp->inuse,
		print_tainted());
		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
		sizeof(slabp) + cachep->num sizeof(kmem_bufctl_t),
		1);

mm/slub.c

+48 −29

Original line number	Diff line number	Diff line
		@@ -570,7 +570,7 @@ static void slab_bug(struct kmem_cache s, char fmt, ...)
		va_end(args);
		printk(KERN_ERR "========================================"
		"=====================================\n");
		printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
		printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf);
		printk(KERN_ERR "----------------------------------------"
		"-------------------------------------\n\n");
		}
		@@ -1901,11 +1901,14 @@ static void unfreeze_partials(struct kmem_cache *s)
		}

		if (l != m) {
		if (l == M_PARTIAL)
		if (l == M_PARTIAL) {
		remove_partial(n, page);
		else
		stat(s, FREE_REMOVE_PARTIAL);
		} else {
		add_partial(n, page,
		DEACTIVATE_TO_TAIL);
		stat(s, FREE_ADD_PARTIAL);
		}

		l = m;
		}
		@@ -2123,6 +2126,37 @@ static inline void new_slab_objects(struct kmem_cache s, gfp_t flags,
		return object;
		}

		/*
		* Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
		* or deactivate the page.
		*
		* The page is still frozen if the return value is not NULL.
		*
		* If this function returns NULL then the page has been unfrozen.
		*/
		static inline void get_freelist(struct kmem_cache s, struct page *page)
		{
		struct page new;
		unsigned long counters;
		void *freelist;

		do {
		freelist = page->freelist;
		counters = page->counters;
		new.counters = counters;
		VM_BUG_ON(!new.frozen);

		new.inuse = page->objects;
		new.frozen = freelist != NULL;

		} while (!cmpxchg_double_slab(s, page,
		freelist, counters,
		NULL, new.counters,
		"get_freelist"));

		return freelist;
		}

		/*
		* Slow path. The lockless freelist is empty or we need to perform
		* debugging duties.
		@@ -2144,8 +2178,6 @@ static void __slab_alloc(struct kmem_cache s, gfp_t gfpflags, int node,
		{
		void **object;
		unsigned long flags;
		struct page new;
		unsigned long counters;

		local_irq_save(flags);
		#ifdef CONFIG_PREEMPT
		@@ -2166,31 +2198,14 @@ redo:
		goto new_slab;
		}

		stat(s, ALLOC_SLOWPATH);

		do {
		object = c->page->freelist;
		counters = c->page->counters;
		new.counters = counters;
		VM_BUG_ON(!new.frozen);

		/*
		* If there is no object left then we use this loop to
		* deactivate the slab which is simple since no objects
		* are left in the slab and therefore we do not need to
		* put the page back onto the partial list.
		*
		* If there are objects left then we retrieve them
		* and use them to refill the per cpu queue.
		*/
		/* must check again c->freelist in case of cpu migration or IRQ */
		object = c->freelist;
		if (object)
		goto load_freelist;

		new.inuse = c->page->objects;
		new.frozen = object != NULL;
		stat(s, ALLOC_SLOWPATH);

		} while (!__cmpxchg_double_slab(s, c->page,
		object, counters,
		NULL, new.counters,
		"__slab_alloc"));
		object = get_freelist(s, c->page);

		if (!object) {
		c->page = NULL;
		@@ -3028,7 +3043,9 @@ static int kmem_cache_open(struct kmem_cache *s,
		* per node list when we run out of per cpu objects. We only fetch 50%
		* to keep some capacity around for frees.
		*/
		if (s->size >= PAGE_SIZE)
		if (kmem_cache_debug(s))
		s->cpu_partial = 0;
		else if (s->size >= PAGE_SIZE)
		s->cpu_partial = 2;
		else if (s->size >= 1024)
		s->cpu_partial = 6;
		@@ -4637,6 +4654,8 @@ static ssize_t cpu_partial_store(struct kmem_cache s, const char buf,
		err = strict_strtoul(buf, 10, &objects);
		if (err)
		return err;
		if (objects && kmem_cache_debug(s))
		return -EINVAL;

		s->cpu_partial = objects;
		flush_all(s);

Admin message