These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 298 insertions, 71 deletions

diff --git a/kernel/mm/slub.c b/kernel/mm/slub.c
index 905e283d7..d304d8802 100644
--- a/kernel/mm/slub.c
+++ b/kernel/mm/slub.c
@@ -459,8 +459,10 @@ static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
 /*
  * Debug settings:
  */
-#ifdef CONFIG_SLUB_DEBUG_ON
+#if defined(CONFIG_SLUB_DEBUG_ON)
 static int slub_debug = DEBUG_DEFAULT_FLAGS;
+#elif defined(CONFIG_KASAN)
+static int slub_debug = SLAB_STORE_USER;
 #else
 static int slub_debug;
 #endif
@@ -1063,11 +1065,15 @@ bad:
 	return 0;
 }
 
+/* Supports checking bulk free of a constructed freelist */
 static noinline struct kmem_cache_node *free_debug_processing(
-	struct kmem_cache *s, struct page *page, void *object,
+	struct kmem_cache *s, struct page *page,
+	void *head, void *tail, int bulk_cnt,
 	unsigned long addr, unsigned long *flags)
 {
 	struct kmem_cache_node *n = get_node(s, page_to_nid(page));
+	void *object = head;
+	int cnt = 0;
 
 	raw_spin_lock_irqsave(&n->list_lock, *flags);
 	slab_lock(page);
@@ -1075,6 +1081,9 @@ static noinline struct kmem_cache_node *free_debug_processing(
 	if (!check_slab(s, page))
 		goto fail;
 
+next_object:
+	cnt++;
+
 	if (!check_valid_pointer(s, page, object)) {
 		slab_err(s, page, "Invalid object pointer 0x%p", object);
 		goto fail;
@@ -1105,8 +1114,19 @@ static noinline struct kmem_cache_node *free_debug_processing(
 	if (s->flags & SLAB_STORE_USER)
 		set_track(s, object, TRACK_FREE, addr);
 	trace(s, page, object, 0);
+	/* Freepointer not overwritten by init_object(), SLAB_POISON moved it */
 	init_object(s, object, SLUB_RED_INACTIVE);
+
+	/* Reached end of constructed freelist yet? */
+	if (object != tail) {
+		object = get_freepointer(s, object);
+		goto next_object;
+	}
 out:
+	if (cnt != bulk_cnt)
+		slab_err(s, page, "Bulk freelist count(%d) invalid(%d)\n",
+			 bulk_cnt, cnt);
+
 	slab_unlock(page);
 	/*
 	 * Keep node_lock to preserve integrity
@@ -1202,7 +1222,7 @@ unsigned long kmem_cache_flags(unsigned long object_size,
 
 	return flags;
 }
-#else
+#else /* !CONFIG_SLUB_DEBUG */
 static inline void setup_object_debug(struct kmem_cache *s,
 			struct page *page, void *object) {}
 
@@ -1210,7 +1230,8 @@ static inline int alloc_debug_processing(struct kmem_cache *s,
 	struct page *page, void *object, unsigned long addr) { return 0; }
 
 static inline struct kmem_cache_node *free_debug_processing(
-	struct kmem_cache *s, struct page *page, void *object,
+	struct kmem_cache *s, struct page *page,
+	void *head, void *tail, int bulk_cnt,
 	unsigned long addr, unsigned long *flags) { return NULL; }
 
 static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
@@ -1269,7 +1290,7 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 {
 	flags &= gfp_allowed_mask;
 	lockdep_trace_alloc(flags);
-	might_sleep_if(flags & __GFP_WAIT);
+	might_sleep_if(gfpflags_allow_blocking(flags));
 
 	if (should_failslab(s->object_size, flags, s->flags))
 		return NULL;
@@ -1277,14 +1298,21 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 	return memcg_kmem_get_cache(s, flags);
 }
 
-static inline void slab_post_alloc_hook(struct kmem_cache *s,
-					gfp_t flags, void *object)
+static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
+					size_t size, void **p)
 {
+	size_t i;
+
 	flags &= gfp_allowed_mask;
-	kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
-	kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags);
+	for (i = 0; i < size; i++) {
+		void *object = p[i];
+
+		kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
+		kmemleak_alloc_recursive(object, s->object_size, 1,
+					 s->flags, flags);
+		kasan_slab_alloc(s, object);
+	}
 	memcg_kmem_put_cache(s);
-	kasan_slab_alloc(s, object);
 }
 
 static inline void slab_free_hook(struct kmem_cache *s, void *x)
@@ -1312,6 +1340,29 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x)
 	kasan_slab_free(s, x);
 }
 
+static inline void slab_free_freelist_hook(struct kmem_cache *s,
+					   void *head, void *tail)
+{
+/*
+ * Compiler cannot detect this function can be removed if slab_free_hook()
+ * evaluates to nothing.  Thus, catch all relevant config debug options here.
+ */
+#if defined(CONFIG_KMEMCHECK) ||		\
+	defined(CONFIG_LOCKDEP)	||		\
+	defined(CONFIG_DEBUG_KMEMLEAK) ||	\
+	defined(CONFIG_DEBUG_OBJECTS_FREE) ||	\
+	defined(CONFIG_KASAN)
+
+	void *object = head;
+	void *tail_obj = tail ? : head;
+
+	do {
+		slab_free_hook(s, object);
+	} while ((object != tail_obj) &&
+		 (object = get_freepointer(s, object)));
+#endif
+}
+
 static void setup_object(struct kmem_cache *s, struct page *page,
 				void *object)
 {
@@ -1334,16 +1385,15 @@ static inline struct page *alloc_slab_page(struct kmem_cache *s,
 
 	flags |= __GFP_NOTRACK;
 
-	if (memcg_charge_slab(s, flags, order))
-		return NULL;
-
 	if (node == NUMA_NO_NODE)
 		page = alloc_pages(flags, order);
 	else
-		page = alloc_pages_exact_node(node, flags, order);
+		page = __alloc_pages_node(node, flags, order);
 
-	if (!page)
-		memcg_uncharge_slab(s, order);
+	if (page && memcg_charge_slab(page, flags, order, s)) {
+		__free_pages(page, order);
+		page = NULL;
+	}
 
 	return page;
 }
@@ -1355,13 +1405,15 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	gfp_t alloc_gfp;
 	void *start, *p;
 	int idx, order;
-	bool enableirqs;
+	bool enableirqs = false;
 
 	flags &= gfp_allowed_mask;
 
-	enableirqs = (flags & __GFP_WAIT) != 0;
+	if (gfpflags_allow_blocking(flags))
+		enableirqs = true;
 #ifdef CONFIG_PREEMPT_RT_FULL
-	enableirqs |= system_state == SYSTEM_RUNNING;
+	if (system_state == SYSTEM_RUNNING)
+		enableirqs = true;
 #endif
 	if (enableirqs)
 		local_irq_enable();
@@ -1373,6 +1425,8 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	 * so we fall-back to the minimum order allocation.
 	 */
 	alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
+	if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min))
+		alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~__GFP_DIRECT_RECLAIM;
 
 	page = alloc_slab_page(s, alloc_gfp, node, oo);
 	if (unlikely(!page)) {
@@ -1485,8 +1539,7 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
 	page_mapcount_reset(page);
 	if (current->reclaim_state)
 		current->reclaim_state->reclaimed_slab += pages;
-	__free_pages(page, order);
-	memcg_uncharge_slab(s, order);
+	__free_kmem_pages(page, order);
 }
 
 static void free_delayed(struct list_head *h)
@@ -1526,10 +1579,7 @@ static void free_slab(struct kmem_cache *s, struct page *page)
 			VM_BUG_ON(s->reserved != sizeof(*head));
 			head = page_address(page) + offset;
 		} else {
-			/*
-			 * RCU free overloads the RCU head over the LRU
-			 */
-			head = (void *)&page->lru;
+			head = &page->rcu_head;
 		}
 
 		call_rcu(head, rcu_free_slab);
@@ -2345,25 +2395,17 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
  * And if we were unable to get a new slab from the partial slab lists then
  * we need to allocate a new slab. This is the slowest path since it involves
  * a call to the page allocator and the setup of a new slab.
+ *
+ * Version of __slab_alloc to use when we know that interrupts are
+ * already disabled (which is the case for bulk allocation).
  */
-static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
-			  unsigned long addr, struct kmem_cache_cpu *c)
+static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
+			  unsigned long addr, struct kmem_cache_cpu *c,
+			  struct list_head *to_free)
 {
 	struct slub_free_list *f;
 	void *freelist;
 	struct page *page;
-	unsigned long flags;
-	LIST_HEAD(tofree);
-
-	local_irq_save(flags);
-#ifdef CONFIG_PREEMPT
-	/*
-	 * We may have been preempted and rescheduled on a different
-	 * cpu before disabling interrupts. Need to reload cpu area
-	 * pointer.
-	 */
-	c = this_cpu_ptr(s->cpu_slab);
-#endif
 
 	page = c->page;
 	if (!page)
@@ -2421,13 +2463,13 @@ load_freelist:
 	VM_BUG_ON(!c->page->frozen);
 	c->freelist = get_freepointer(s, freelist);
 	c->tid = next_tid(c->tid);
+
 out:
 	f = this_cpu_ptr(&slub_free_list);
 	raw_spin_lock(&f->lock);
-	list_splice_init(&f->list, &tofree);
+	list_splice_init(&f->list, to_free);
 	raw_spin_unlock(&f->lock);
-	local_irq_restore(flags);
-	free_delayed(&tofree);
+
 	return freelist;
 
 new_slab:
@@ -2444,7 +2486,7 @@ new_slab:
 
 	if (unlikely(!freelist)) {
 		slab_out_of_memory(s, gfpflags, node);
-		goto out;
+		return NULL;
 	}
 
 	page = c->page;
@@ -2463,6 +2505,33 @@ new_slab:
 }
 
 /*
+ * Another one that disabled interrupt and compensates for possible
+ * cpu changes by refetching the per cpu area pointer.
+ */
+static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
+			  unsigned long addr, struct kmem_cache_cpu *c)
+{
+	void *p;
+	unsigned long flags;
+	LIST_HEAD(tofree);
+
+	local_irq_save(flags);
+#ifdef CONFIG_PREEMPT
+	/*
+	 * We may have been preempted and rescheduled on a different
+	 * cpu before disabling interrupts. Need to reload cpu area
+	 * pointer.
+	 */
+	c = this_cpu_ptr(s->cpu_slab);
+#endif
+
+	p = ___slab_alloc(s, gfpflags, node, addr, c, &tofree);
+	local_irq_restore(flags);
+	free_delayed(&tofree);
+	return p;
+}
+
+/*
  * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
  * have the fastpath folded into their functions. So no function call
  * overhead for requests that can be satisfied on the fastpath.
@@ -2475,7 +2544,7 @@ new_slab:
 static __always_inline void *slab_alloc_node(struct kmem_cache *s,
 		gfp_t gfpflags, int node, unsigned long addr)
 {
-	void **object;
+	void *object;
 	struct kmem_cache_cpu *c;
 	struct page *page;
 	unsigned long tid;
@@ -2554,7 +2623,7 @@ redo:
 	if (unlikely(gfpflags & __GFP_ZERO) && object)
 		memset(object, 0, s->object_size);
 
-	slab_post_alloc_hook(s, gfpflags, object);
+	slab_post_alloc_hook(s, gfpflags, 1, &object);
 
 	return object;
 }
@@ -2625,10 +2694,11 @@ EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
  * handling required then we can return immediately.
  */
 static void __slab_free(struct kmem_cache *s, struct page *page,
-			void *x, unsigned long addr)
+			void *head, void *tail, int cnt,
+			unsigned long addr)
+
 {
 	void *prior;
-	void **object = (void *)x;
 	int was_frozen;
 	struct page new;
 	unsigned long counters;
@@ -2638,7 +2708,8 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 	stat(s, FREE_SLOWPATH);
 
 	if (kmem_cache_debug(s) &&
-		!(n = free_debug_processing(s, page, x, addr, &flags)))
+	    !(n = free_debug_processing(s, page, head, tail, cnt,
+					addr, &flags)))
 		return;
 
 	do {
@@ -2648,10 +2719,10 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 		}
 		prior = page->freelist;
 		counters = page->counters;
-		set_freepointer(s, object, prior);
+		set_freepointer(s, tail, prior);
 		new.counters = counters;
 		was_frozen = new.frozen;
-		new.inuse--;
+		new.inuse -= cnt;
 		if ((!new.inuse || !prior) && !was_frozen) {
 
 			if (kmem_cache_has_cpu_partial(s) && !prior) {
@@ -2682,7 +2753,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 
 	} while (!cmpxchg_double_slab(s, page,
 		prior, counters,
-		object, new.counters,
+		head, new.counters,
 		"__slab_free"));
 
 	if (likely(!n)) {
@@ -2747,22 +2818,27 @@ slab_empty:
  *
  * If fastpath is not possible then fall back to __slab_free where we deal
  * with all sorts of special processing.
+ *
+ * Bulk free of a freelist with several objects (all pointing to the
+ * same page) possible by specifying head and tail ptr, plus objects
+ * count (cnt). Bulk free indicated by tail pointer being set.
  */
-static __always_inline void slab_free(struct kmem_cache *s,
-			struct page *page, void *x, unsigned long addr)
+static __always_inline void slab_free(struct kmem_cache *s, struct page *page,
+				      void *head, void *tail, int cnt,
+				      unsigned long addr)
 {
-	void **object = (void *)x;
+	void *tail_obj = tail ? : head;
 	struct kmem_cache_cpu *c;
 	unsigned long tid;
 
-	slab_free_hook(s, x);
+	slab_free_freelist_hook(s, head, tail);
 
 redo:
 	/*
 	 * Determine the currently cpus per cpu slab.
 	 * The cpu may change afterward. However that does not matter since
 	 * data is retrieved via this pointer. If we are on the same cpu
-	 * during the cmpxchg then the free will succedd.
+	 * during the cmpxchg then the free will succeed.
 	 */
 	do {
 		tid = this_cpu_read(s->cpu_slab->tid);
@@ -2774,19 +2850,19 @@ redo:
 	barrier();
 
 	if (likely(page == c->page)) {
-		set_freepointer(s, object, c->freelist);
+		set_freepointer(s, tail_obj, c->freelist);
 
 		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
-				object, next_tid(tid)))) {
+				head, next_tid(tid)))) {
 
 			note_cmpxchg_failure("slab_free", s, tid);
 			goto redo;
 		}
 		stat(s, FREE_FASTPATH);
 	} else
-		__slab_free(s, page, x, addr);
+		__slab_free(s, page, head, tail_obj, cnt, addr);
 
 }
 
@@ -2795,11 +2871,168 @@ void kmem_cache_free(struct kmem_cache *s, void *x)
 	s = cache_from_obj(s, x);
 	if (!s)
 		return;
-	slab_free(s, virt_to_head_page(x), x, _RET_IP_);
+	slab_free(s, virt_to_head_page(x), x, NULL, 1, _RET_IP_);
 	trace_kmem_cache_free(_RET_IP_, x);
 }
 EXPORT_SYMBOL(kmem_cache_free);
 
+struct detached_freelist {
+	struct page *page;
+	void *tail;
+	void *freelist;
+	int cnt;
+};
+
+/*
+ * This function progressively scans the array with free objects (with
+ * a limited look ahead) and extract objects belonging to the same
+ * page.  It builds a detached freelist directly within the given
+ * page/objects.  This can happen without any need for
+ * synchronization, because the objects are owned by running process.
+ * The freelist is build up as a single linked list in the objects.
+ * The idea is, that this detached freelist can then be bulk
+ * transferred to the real freelist(s), but only requiring a single
+ * synchronization primitive.  Look ahead in the array is limited due
+ * to performance reasons.
+ */
+static int build_detached_freelist(struct kmem_cache *s, size_t size,
+				   void **p, struct detached_freelist *df)
+{
+	size_t first_skipped_index = 0;
+	int lookahead = 3;
+	void *object;
+
+	/* Always re-init detached_freelist */
+	df->page = NULL;
+
+	do {
+		object = p[--size];
+	} while (!object && size);
+
+	if (!object)
+		return 0;
+
+	/* Start new detached freelist */
+	set_freepointer(s, object, NULL);
+	df->page = virt_to_head_page(object);
+	df->tail = object;
+	df->freelist = object;
+	p[size] = NULL; /* mark object processed */
+	df->cnt = 1;
+
+	while (size) {
+		object = p[--size];
+		if (!object)
+			continue; /* Skip processed objects */
+
+		/* df->page is always set at this point */
+		if (df->page == virt_to_head_page(object)) {
+			/* Opportunity build freelist */
+			set_freepointer(s, object, df->freelist);
+			df->freelist = object;
+			df->cnt++;
+			p[size] = NULL; /* mark object processed */
+
+			continue;
+		}
+
+		/* Limit look ahead search */
+		if (!--lookahead)
+			break;
+
+		if (!first_skipped_index)
+			first_skipped_index = size + 1;
+	}
+
+	return first_skipped_index;
+}
+
+
+/* Note that interrupts must be enabled when calling this function. */
+void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
+{
+	if (WARN_ON(!size))
+		return;
+
+	do {
+		struct detached_freelist df;
+		struct kmem_cache *s;
+
+		/* Support for memcg */
+		s = cache_from_obj(orig_s, p[size - 1]);
+
+		size = build_detached_freelist(s, size, p, &df);
+		if (unlikely(!df.page))
+			continue;
+
+		slab_free(s, df.page, df.freelist, df.tail, df.cnt, _RET_IP_);
+	} while (likely(size));
+}
+EXPORT_SYMBOL(kmem_cache_free_bulk);
+
+/* Note that interrupts must be enabled when calling this function. */
+int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
+			  void **p)
+{
+	struct kmem_cache_cpu *c;
+	LIST_HEAD(to_free);
+	int i;
+
+	/* memcg and kmem_cache debug support */
+	s = slab_pre_alloc_hook(s, flags);
+	if (unlikely(!s))
+		return false;
+	/*
+	 * Drain objects in the per cpu slab, while disabling local
+	 * IRQs, which protects against PREEMPT and interrupts
+	 * handlers invoking normal fastpath.
+	 */
+	local_irq_disable();
+	c = this_cpu_ptr(s->cpu_slab);
+
+	for (i = 0; i < size; i++) {
+		void *object = c->freelist;
+
+		if (unlikely(!object)) {
+			/*
+			 * Invoking slow path likely have side-effect
+			 * of re-populating per CPU c->freelist
+			 */
+			p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
+					    _RET_IP_, c, &to_free);
+			if (unlikely(!p[i]))
+				goto error;
+
+			c = this_cpu_ptr(s->cpu_slab);
+			continue; /* goto for-loop */
+		}
+		c->freelist = get_freepointer(s, object);
+		p[i] = object;
+	}
+	c->tid = next_tid(c->tid);
+	local_irq_enable();
+	free_delayed(&to_free);
+
+	/* Clear memory outside IRQ disabled fastpath loop */
+	if (unlikely(flags & __GFP_ZERO)) {
+		int j;
+
+		for (j = 0; j < i; j++)
+			memset(p[j], 0, s->object_size);
+	}
+
+	/* memcg and kmem_cache debug support */
+	slab_post_alloc_hook(s, flags, size, p);
+	return i;
+error:
+	local_irq_enable();
+	slab_post_alloc_hook(s, flags, i, p);
+	__kmem_cache_free_bulk(s, i, p);
+	return 0;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_bulk);
+
+
 /*
  * Object placement in a slab is made very easy because we always start at
  * offset 0. If we tune the size of the object to the alignment then we can
@@ -2858,20 +3091,15 @@ static inline int slab_order(int size, int min_objects,
 	if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
 		return get_order(size * MAX_OBJS_PER_PAGE) - 1;
 
-	for (order = max(min_order,
-				fls(min_objects * size - 1) - PAGE_SHIFT);
+	for (order = max(min_order, get_order(min_objects * size + reserved));
 			order <= max_order; order++) {
 
 		unsigned long slab_size = PAGE_SIZE << order;
 
-		if (slab_size < min_objects * size + reserved)
-			continue;
-
 		rem = (slab_size - reserved) % size;
 
 		if (rem <= slab_size / fract_leftover)
 			break;
-
 	}
 
 	return order;
@@ -2889,7 +3117,7 @@ static inline int calculate_order(int size, int reserved)
 	 * works by first attempting to generate a layout with
 	 * the best configuration and backing off gradually.
 	 *
-	 * First we reduce the acceptable waste in a slab. Then
+	 * First we increase the acceptable waste in a slab. Then
 	 * we reduce the minimum objects required in a slab.
 	 */
 	min_objects = slub_min_objects;
@@ -3465,7 +3693,7 @@ void kfree(const void *x)
 		__free_kmem_pages(page, compound_order(page));
 		return;
 	}
-	slab_free(page->slab_cache, page, object, _RET_IP_);
+	slab_free(page->slab_cache, page, object, NULL, 1, _RET_IP_);
 }
 EXPORT_SYMBOL(kfree);
 
@@ -3756,6 +3984,7 @@ void __init kmem_cache_init(void)
 	kmem_cache_node = bootstrap(&boot_kmem_cache_node);
 
 	/* Now we can use the kmem_cache to allocate kmalloc slabs */
+	setup_kmalloc_cache_index_table();
 	create_kmalloc_caches(0);
 
 #ifdef CONFIG_SMP
@@ -5236,7 +5465,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
 	s->kobj.kset = cache_kset(s);
 	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
 	if (err)
-		goto out_put_kobj;
+		goto out;
 
 	err = sysfs_create_group(&s->kobj, &slab_attr_group);
 	if (err)
@@ -5263,8 +5492,6 @@ out:
 	return err;
 out_del_kobj:
 	kobject_del(&s->kobj);
-out_put_kobj:
-	kobject_put(&s->kobj);
 	goto out;
 }