From 1684df2ad25964a7fa192cefac10ea28b7f6946a Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:44:11 -0500
Subject: [PATCH] mm: Restructure slab to use percpu locked data structures

commit a20e0cb87d49f65bea34026c7dfe364c035a1123 in tip.

Instead of relying on preemption disabled rt protects the per cpu data
structures with per cpu locks.

This patch contains fixes from
     Andi Kleen <ak@suse.de>
     Peter Zijlstra <a.p.zijlstra@chello.nl>
     Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/mm/slab.c b/mm/slab.c
index a9f325b..3164b8d 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -121,6 +121,120 @@
 #include	<asm/page.h>
 
 /*
+ * On !PREEMPT_RT, raw irq flags are used as a per-CPU locking
+ * mechanism.
+ *
+ * On PREEMPT_RT, we use per-CPU locks for this. That's why the
+ * calling convention is changed slightly: a new 'flags' argument
+ * is passed to 'irq disable/enable' - the PREEMPT_RT code stores
+ * the CPU number of the lock there.
+ */
+#ifndef CONFIG_PREEMPT_RT
+
+# define slab_irq_disable(cpu) \
+	do { local_irq_disable(); (cpu) = smp_processor_id(); } while (0)
+# define slab_irq_enable(cpu)		local_irq_enable()
+
+static inline void slab_irq_disable_this_rt(int cpu)
+{
+}
+
+static inline void slab_irq_enable_rt(int cpu)
+{
+}
+
+# define slab_irq_save(flags, cpu) \
+	do { local_irq_save(flags); (cpu) = smp_processor_id(); } while (0)
+# define slab_irq_restore(flags, cpu)	local_irq_restore(flags)
+
+/*
+ * In the __GFP_WAIT case we enable/disable interrupts on !PREEMPT_RT,
+ * which has no per-CPU locking effect since we are holding the cache
+ * lock in that case already.
+ */
+static void slab_irq_enable_GFP_WAIT(gfp_t flags, int *cpu)
+{
+	if (flags & __GFP_WAIT)
+		local_irq_enable();
+}
+
+static void slab_irq_disable_GFP_WAIT(gfp_t flags, int *cpu)
+{
+	if (flags & __GFP_WAIT)
+		local_irq_disable();
+}
+
+# define slab_spin_lock_irq(lock, cpu) \
+	do { spin_lock_irq(lock); (cpu) = smp_processor_id(); } while (0)
+# define slab_spin_unlock_irq(lock, cpu) spin_unlock_irq(lock)
+
+# define slab_spin_lock_irqsave(lock, flags, cpu) \
+	do { spin_lock_irqsave(lock, flags); (cpu) = smp_processor_id(); } while (0)
+# define slab_spin_unlock_irqrestore(lock, flags, cpu) \
+	do { spin_unlock_irqrestore(lock, flags); } while (0)
+
+#else /* CONFIG_PREEMPT_RT */
+
+/*
+ * Instead of serializing the per-cpu state by disabling interrupts we do so
+ * by a lock. This keeps the code preemptable - albeit at the cost of remote
+ * memory access when the task does get migrated away.
+ */
+DEFINE_PER_CPU_LOCKED(int, slab_irq_locks) = { 0, };
+
+static void _slab_irq_disable(int *cpu)
+{
+	get_cpu_var_locked(slab_irq_locks, cpu);
+}
+
+#define slab_irq_disable(cpu) _slab_irq_disable(&(cpu))
+
+static inline void slab_irq_enable(int cpu)
+{
+	put_cpu_var_locked(slab_irq_locks, cpu);
+}
+
+static inline void slab_irq_disable_this_rt(int cpu)
+{
+	spin_lock(&__get_cpu_lock(slab_irq_locks, cpu));
+}
+
+static inline void slab_irq_enable_rt(int cpu)
+{
+	spin_unlock(&__get_cpu_lock(slab_irq_locks, cpu));
+}
+
+# define slab_irq_save(flags, cpu) \
+	do { slab_irq_disable(cpu); (void) (flags); } while (0)
+# define slab_irq_restore(flags, cpu) \
+	do { slab_irq_enable(cpu); (void) (flags); } while (0)
+
+/*
+ * On PREEMPT_RT we have to drop the locks unconditionally to avoid lock
+ * recursion on the cache_grow()->alloc_slabmgmt() path.
+ */
+static void slab_irq_enable_GFP_WAIT(gfp_t flags, int *cpu)
+{
+	slab_irq_enable(*cpu);
+}
+
+static void slab_irq_disable_GFP_WAIT(gfp_t flags, int *cpu)
+{
+	slab_irq_disable(*cpu);
+}
+
+# define slab_spin_lock_irq(lock, cpu) \
+		do { slab_irq_disable(cpu); spin_lock(lock); } while (0)
+# define slab_spin_unlock_irq(lock, cpu) \
+		do { spin_unlock(lock); slab_irq_enable(cpu); } while (0)
+# define slab_spin_lock_irqsave(lock, flags, cpu) \
+	do { slab_irq_disable(cpu); spin_lock_irqsave(lock, flags); } while (0)
+# define slab_spin_unlock_irqrestore(lock, flags, cpu) \
+	do { spin_unlock_irqrestore(lock, flags); slab_irq_enable(cpu); } while (0)
+
+#endif /* CONFIG_PREEMPT_RT */
+
+/*
  * DEBUG	- 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
  *		  0 for faster, smaller code (especially in the critical paths).
  *
@@ -316,7 +430,7 @@ struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
 static int drain_freelist(struct kmem_cache *cache,
 			struct kmem_list3 *l3, int tofree);
 static void free_block(struct kmem_cache *cachep, void **objpp, int len,
-			int node);
+		       int node, int *this_cpu);
 static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
 static void cache_reap(struct work_struct *unused);
 
@@ -699,9 +813,10 @@ static struct list_head cache_chain;
 
 static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
 
-static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
+static inline struct array_cache *
+cpu_cache_get(struct kmem_cache *cachep, int this_cpu)
 {
-	return cachep->array[smp_processor_id()];
+	return cachep->array[this_cpu];
 }
 
 static inline struct kmem_cache *__find_general_cachep(size_t size,
@@ -941,7 +1056,7 @@ static int transfer_objects(struct array_cache *to,
 #ifndef CONFIG_NUMA
 
 #define drain_alien_cache(cachep, alien) do { } while (0)
-#define reap_alien(cachep, l3) do { } while (0)
+#define reap_alien(cachep, l3, this_cpu) 0
 
 static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
 {
@@ -952,27 +1067,28 @@ static inline void free_alien_cache(struct array_cache **ac_ptr)
 {
 }
 
-static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
+static inline int
+cache_free_alien(struct kmem_cache *cachep, void *objp, int *this_cpu)
 {
 	return 0;
 }
 
 static inline void *alternate_node_alloc(struct kmem_cache *cachep,
-		gfp_t flags)
+					 gfp_t flags, int *this_cpu)
 {
 	return NULL;
 }
 
 static inline void *____cache_alloc_node(struct kmem_cache *cachep,
-		 gfp_t flags, int nodeid)
+					 gfp_t flags, int nodeid, int *this_cpu)
 {
 	return NULL;
 }
 
 #else	/* CONFIG_NUMA */
 
-static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
-static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
+static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int, int *);
+static void *alternate_node_alloc(struct kmem_cache *, gfp_t, int *);
 
 static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
 {
@@ -1011,7 +1127,8 @@ static void free_alien_cache(struct array_cache **ac_ptr)
 }
 
 static void __drain_alien_cache(struct kmem_cache *cachep,
-				struct array_cache *ac, int node)
+				struct array_cache *ac, int node,
+				int *this_cpu)
 {
 	struct kmem_list3 *rl3 = cachep->nodelists[node];
 
@@ -1025,7 +1142,7 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
 		if (rl3->shared)
 			transfer_objects(rl3->shared, ac, ac->limit);
 
-		free_block(cachep, ac->entry, ac->avail, node);
+		free_block(cachep, ac->entry, ac->avail, node, this_cpu);
 		ac->avail = 0;
 		spin_unlock(&rl3->list_lock);
 	}
@@ -1034,38 +1151,42 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
 /*
  * Called from cache_reap() to regularly drain alien caches round robin.
  */
-static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
+static int
+reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3, int *this_cpu)
 {
-	int node = __get_cpu_var(slab_reap_node);
+	int node = per_cpu(slab_reap_node, *this_cpu);
 
 	if (l3->alien) {
 		struct array_cache *ac = l3->alien[node];
 
 		if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
-			__drain_alien_cache(cachep, ac, node);
+			__drain_alien_cache(cachep, ac, node, this_cpu);
 			spin_unlock_irq(&ac->lock);
+			return 1;
 		}
 	}
+	return 0;
 }
 
 static void drain_alien_cache(struct kmem_cache *cachep,
 				struct array_cache **alien)
 {
-	int i = 0;
+	int this_cpu, i = 0;
 	struct array_cache *ac;
 	unsigned long flags;
 
 	for_each_online_node(i) {
 		ac = alien[i];
 		if (ac) {
-			spin_lock_irqsave(&ac->lock, flags);
-			__drain_alien_cache(cachep, ac, i);
-			spin_unlock_irqrestore(&ac->lock, flags);
+			slab_spin_lock_irqsave(&ac->lock, flags, this_cpu);
+			__drain_alien_cache(cachep, ac, i, &this_cpu);
+			slab_spin_unlock_irqrestore(&ac->lock, flags, this_cpu);
 		}
 	}
 }
 
-static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
+static inline int
+cache_free_alien(struct kmem_cache *cachep, void *objp, int *this_cpu)
 {
 	struct slab *slabp = virt_to_slab(objp);
 	int nodeid = slabp->nodeid;
@@ -1073,7 +1194,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
 	struct array_cache *alien = NULL;
 	int node;
 
-	node = numa_node_id();
+	node = cpu_to_node(*this_cpu);
 
 	/*
 	 * Make sure we are not freeing a object from another node to the array
@@ -1089,20 +1210,20 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
 		spin_lock(&alien->lock);
 		if (unlikely(alien->avail == alien->limit)) {
 			STATS_INC_ACOVERFLOW(cachep);
-			__drain_alien_cache(cachep, alien, nodeid);
+			__drain_alien_cache(cachep, alien, nodeid, this_cpu);
 		}
 		alien->entry[alien->avail++] = objp;
 		spin_unlock(&alien->lock);
 	} else {
 		spin_lock(&(cachep->nodelists[nodeid])->list_lock);
-		free_block(cachep, &objp, 1, nodeid);
+		free_block(cachep, &objp, 1, nodeid, this_cpu);
 		spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
 	}
 	return 1;
 }
 #endif
 
-static void __cpuinit cpuup_canceled(long cpu)
+static void __cpuinit cpuup_canceled(int cpu)
 {
 	struct kmem_cache *cachep;
 	struct kmem_list3 *l3 = NULL;
@@ -1113,6 +1234,7 @@ static void __cpuinit cpuup_canceled(long cpu)
 		struct array_cache *nc;
 		struct array_cache *shared;
 		struct array_cache **alien;
+		int orig_cpu = cpu;
 
 		/* cpu is dead; no one can alloc from it. */
 		nc = cachep->array[cpu];
@@ -1127,7 +1249,7 @@ static void __cpuinit cpuup_canceled(long cpu)
 		/* Free limit for this kmem_list3 */
 		l3->free_limit -= cachep->batchcount;
 		if (nc)
-			free_block(cachep, nc->entry, nc->avail, node);
+			free_block(cachep, nc->entry, nc->avail, node, &cpu);
 
 		if (!cpumask_empty(mask)) {
 			spin_unlock_irq(&l3->list_lock);
@@ -1137,7 +1259,7 @@ static void __cpuinit cpuup_canceled(long cpu)
 		shared = l3->shared;
 		if (shared) {
 			free_block(cachep, shared->entry,
-				   shared->avail, node);
+				   shared->avail, node, &cpu);
 			l3->shared = NULL;
 		}
 
@@ -1153,6 +1275,7 @@ static void __cpuinit cpuup_canceled(long cpu)
 		}
 free_array_cache:
 		kfree(nc);
+		BUG_ON(cpu != orig_cpu);
 	}
 	/*
 	 * In the previous loop, all the objects were freed to
@@ -1167,7 +1290,7 @@ free_array_cache:
 	}
 }
 
-static int __cpuinit cpuup_prepare(long cpu)
+static int __cpuinit cpuup_prepare(int cpu)
 {
 	struct kmem_cache *cachep;
 	struct kmem_list3 *l3 = NULL;
@@ -1277,10 +1400,19 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
 	long cpu = (long)hcpu;
 	int err = 0;
 
+
 	switch (action) {
 	case CPU_UP_PREPARE:
 	case CPU_UP_PREPARE_FROZEN:
 		mutex_lock(&cache_chain_mutex);
+		/*
+		 * lock/unlock cycle to push any holders away -- no new ones
+		 * can come in due to the cpu still being offline.
+		 *
+		 * XXX -- weird case anyway, can it happen?
+		 */
+		slab_irq_disable_this_rt(cpu);
+		slab_irq_enable_rt(cpu);
 		err = cpuup_prepare(cpu);
 		mutex_unlock(&cache_chain_mutex);
 		break;
@@ -1320,10 +1452,14 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
 	case CPU_UP_CANCELED:
 	case CPU_UP_CANCELED_FROZEN:
 		mutex_lock(&cache_chain_mutex);
+		slab_irq_disable_this_rt(cpu);
 		cpuup_canceled(cpu);
+		slab_irq_enable_rt(cpu);
 		mutex_unlock(&cache_chain_mutex);
 		break;
 	}
+
+
 	return err ? NOTIFY_BAD : NOTIFY_OK;
 }
 
@@ -1510,32 +1646,34 @@ void __init kmem_cache_init(void)
 	/* 4) Replace the bootstrap head arrays */
 	{
 		struct array_cache *ptr;
+		int cpu = smp_processor_id();
 
 		ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
 
-		BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
-		memcpy(ptr, cpu_cache_get(&cache_cache),
+		BUG_ON(cpu_cache_get(&cache_cache, cpu) !=
+		       &initarray_cache.cache);
+		memcpy(ptr, cpu_cache_get(&cache_cache, cpu),
 		       sizeof(struct arraycache_init));
 		/*
 		 * Do not assume that spinlocks can be initialized via memcpy:
 		 */
 		spin_lock_init(&ptr->lock);
 
-		cache_cache.array[smp_processor_id()] = ptr;
+		cache_cache.array[cpu] = ptr;
 
 		ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
 
-		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
+		BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep, cpu)
 		       != &initarray_generic.cache);
-		memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
+		memcpy(ptr,
+		       cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep, cpu),
 		       sizeof(struct arraycache_init));
 		/*
 		 * Do not assume that spinlocks can be initialized via memcpy:
 		 */
 		spin_lock_init(&ptr->lock);
 
-		malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
-		    ptr;
+		malloc_sizes[INDEX_AC].cs_cachep->array[cpu] = ptr;
 	}
 	/* 5) Replace the bootstrap kmem_list3's */
 	{
@@ -1702,7 +1840,7 @@ static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
 
 	*addr++ = 0x12345678;
 	*addr++ = caller;
-	*addr++ = smp_processor_id();
+	*addr++ = raw_smp_processor_id();
 	size -= 3 * sizeof(unsigned long);
 	{
 		unsigned long *sptr = &caller;
@@ -1892,6 +2030,10 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
 }
 #endif
 
+static void
+__cache_free(struct kmem_cache *cachep, void *objp, int *this_cpu);
+
+
 /**
  * slab_destroy - destroy and release all objects in a slab
  * @cachep: cache pointer being destroyed
@@ -1901,7 +2043,8 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
  * Before calling the slab must have been unlinked from the cache.  The
  * cache-lock is not held/needed.
  */
-static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
+static void
+slab_destroy(struct kmem_cache *cachep, struct slab *slabp, int *this_cpu)
 {
 	void *addr = slabp->s_mem - slabp->colouroff;
 
@@ -1915,8 +2058,12 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 		call_rcu(&slab_rcu->head, kmem_rcu_free);
 	} else {
 		kmem_freepages(cachep, addr);
-		if (OFF_SLAB(cachep))
-			kmem_cache_free(cachep->slabp_cache, slabp);
+		if (OFF_SLAB(cachep)) {
+			if (this_cpu)
+				__cache_free(cachep->slabp_cache, slabp, this_cpu);
+			else
+				kmem_cache_free(cachep->slabp_cache, slabp);
+		}
 	}
 }
 
@@ -2013,6 +2160,8 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
 
 static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
 {
+	int this_cpu;
+
 	if (g_cpucache_up == FULL)
 		return enable_cpucache(cachep, gfp);
 
@@ -2056,10 +2205,12 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
 			jiffies + REAPTIMEOUT_LIST3 +
 			((unsigned long)cachep) % REAPTIMEOUT_LIST3;
 
-	cpu_cache_get(cachep)->avail = 0;
-	cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
-	cpu_cache_get(cachep)->batchcount = 1;
-	cpu_cache_get(cachep)->touched = 0;
+	this_cpu = raw_smp_processor_id();
+
+	cpu_cache_get(cachep, this_cpu)->avail = 0;
+	cpu_cache_get(cachep, this_cpu)->limit = BOOT_CPUCACHE_ENTRIES;
+	cpu_cache_get(cachep, this_cpu)->batchcount = 1;
+	cpu_cache_get(cachep, this_cpu)->touched = 0;
 	cachep->batchcount = 1;
 	cachep->limit = BOOT_CPUCACHE_ENTRIES;
 	return 0;
@@ -2371,19 +2522,19 @@ EXPORT_SYMBOL(kmem_cache_create);
 #if DEBUG
 static void check_irq_off(void)
 {
+/*
+ * On PREEMPT_RT we use locks to protect the per-CPU lists,
+ * and keep interrupts enabled.
+ */
+#ifndef CONFIG_PREEMPT_RT
 	BUG_ON(!irqs_disabled());
+#endif
 }
 
 static void check_irq_on(void)
 {
+#ifndef CONFIG_PREEMPT_RT
 	BUG_ON(irqs_disabled());
-}
-
-static void check_spinlock_acquired(struct kmem_cache *cachep)
-{
-#ifdef CONFIG_SMP
-	check_irq_off();
-	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
 #endif
 }
 
@@ -2398,34 +2549,67 @@ static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
 #else
 #define check_irq_off()	do { } while(0)
 #define check_irq_on()	do { } while(0)
-#define check_spinlock_acquired(x) do { } while(0)
 #define check_spinlock_acquired_node(x, y) do { } while(0)
 #endif
 
-static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
+static int drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
 			struct array_cache *ac,
 			int force, int node);
 
-static void do_drain(void *arg)
+static void __do_drain(void *arg, int this_cpu)
 {
 	struct kmem_cache *cachep = arg;
+	int node = cpu_to_node(this_cpu);
 	struct array_cache *ac;
-	int node = numa_node_id();
 
 	check_irq_off();
-	ac = cpu_cache_get(cachep);
+	ac = cpu_cache_get(cachep, this_cpu);
 	spin_lock(&cachep->nodelists[node]->list_lock);
-	free_block(cachep, ac->entry, ac->avail, node);
+	free_block(cachep, ac->entry, ac->avail, node, &this_cpu);
 	spin_unlock(&cachep->nodelists[node]->list_lock);
 	ac->avail = 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_drain(void *arg, int this_cpu)
+{
+	__do_drain(arg, this_cpu);
+}
+#else
+static void do_drain(void *arg)
+{
+	__do_drain(arg, smp_processor_id());
+}
+#endif
+
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * execute func() for all CPUs. On PREEMPT_RT we dont actually have
+ * to run on the remote CPUs - we only have to take their CPU-locks.
+ * (This is a rare operation, so cacheline bouncing is not an issue.)
+ */
+static void
+slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg)
+{
+	unsigned int i;
+
+	check_irq_on();
+	for_each_online_cpu(i) {
+		spin_lock(&__get_cpu_lock(slab_irq_locks, i));
+		func(arg, i);
+		spin_unlock(&__get_cpu_lock(slab_irq_locks, i));
+	}
+}
+#else
+# define slab_on_each_cpu(func, cachep) on_each_cpu(func, cachep, 1)
+#endif
+
 static void drain_cpu_caches(struct kmem_cache *cachep)
 {
 	struct kmem_list3 *l3;
 	int node;
 
-	on_each_cpu(do_drain, cachep, 1);
+	slab_on_each_cpu(do_drain, cachep);
 	check_irq_on();
 	for_each_online_node(node) {
 		l3 = cachep->nodelists[node];
@@ -2450,16 +2634,16 @@ static int drain_freelist(struct kmem_cache *cache,
 			struct kmem_list3 *l3, int tofree)
 {
 	struct list_head *p;
-	int nr_freed;
+	int nr_freed, this_cpu;
 	struct slab *slabp;
 
 	nr_freed = 0;
 	while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
 
-		spin_lock_irq(&l3->list_lock);
+		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 		p = l3->slabs_free.prev;
 		if (p == &l3->slabs_free) {
-			spin_unlock_irq(&l3->list_lock);
+			slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 			goto out;
 		}
 
@@ -2468,13 +2652,9 @@ static int drain_freelist(struct kmem_cache *cache,
 		BUG_ON(slabp->inuse);
 #endif
 		list_del(&slabp->list);
-		/*
-		 * Safe to drop the lock. The slab is no longer linked
-		 * to the cache.
-		 */
 		l3->free_objects -= cache->num;
-		spin_unlock_irq(&l3->list_lock);
-		slab_destroy(cache, slabp);
+		slab_destroy(cache, slabp, &this_cpu);
+		slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 		nr_freed++;
 	}
 out:
@@ -2738,8 +2918,8 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
  * Grow (by 1) the number of slabs within a cache.  This is called by
  * kmem_cache_alloc() when there are no active objs left in a cache.
  */
-static int cache_grow(struct kmem_cache *cachep,
-		gfp_t flags, int nodeid, void *objp)
+static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid,
+		      void *objp, int *this_cpu)
 {
 	struct slab *slabp;
 	size_t offset;
@@ -2767,8 +2947,7 @@ static int cache_grow(struct kmem_cache *cachep,
 
 	offset *= cachep->colour_off;
 
-	if (local_flags & __GFP_WAIT)
-		local_irq_enable();
+	slab_irq_enable_GFP_WAIT(local_flags, this_cpu);
 
 	/*
 	 * The test for missing atomic flag is performed here, rather than
@@ -2797,8 +2976,8 @@ static int cache_grow(struct kmem_cache *cachep,
 
 	cache_init_objs(cachep, slabp);
 
-	if (local_flags & __GFP_WAIT)
-		local_irq_disable();
+	slab_irq_disable_GFP_WAIT(local_flags, this_cpu);
+
 	check_irq_off();
 	spin_lock(&l3->list_lock);
 
@@ -2811,8 +2990,7 @@ static int cache_grow(struct kmem_cache *cachep,
 opps1:
 	kmem_freepages(cachep, objp);
 failed:
-	if (local_flags & __GFP_WAIT)
-		local_irq_disable();
+	slab_irq_disable_GFP_WAIT(local_flags, this_cpu);
 	return 0;
 }
 
@@ -2934,7 +3112,8 @@ bad:
 #define check_slabp(x,y) do { } while(0)
 #endif
 
-static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
+static void *
+cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, int *this_cpu)
 {
 	int batchcount;
 	struct kmem_list3 *l3;
@@ -2944,7 +3123,7 @@ static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
 retry:
 	check_irq_off();
 	node = numa_node_id();
-	ac = cpu_cache_get(cachep);
+	ac = cpu_cache_get(cachep, *this_cpu);
 	batchcount = ac->batchcount;
 	if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
 		/*
@@ -2954,7 +3133,7 @@ retry:
 		 */
 		batchcount = BATCHREFILL_LIMIT;
 	}
-	l3 = cachep->nodelists[node];
+	l3 = cachep->nodelists[cpu_to_node(*this_cpu)];
 
 	BUG_ON(ac->avail > 0 || !l3);
 	spin_lock(&l3->list_lock);
@@ -2979,7 +3158,7 @@ retry:
 
 		slabp = list_entry(entry, struct slab, list);
 		check_slabp(cachep, slabp);
-		check_spinlock_acquired(cachep);
+		check_spinlock_acquired_node(cachep, cpu_to_node(*this_cpu));
 
 		/*
 		 * The slab was either on partial or free list so
@@ -2993,8 +3172,9 @@ retry:
 			STATS_INC_ACTIVE(cachep);
 			STATS_SET_HIGH(cachep);
 
-			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
-							    node);
+			ac->entry[ac->avail++] =
+				slab_get_obj(cachep, slabp,
+					     cpu_to_node(*this_cpu));
 		}
 		check_slabp(cachep, slabp);
 
@@ -3013,10 +3193,10 @@ alloc_done:
 
 	if (unlikely(!ac->avail)) {
 		int x;
-		x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
+		x = cache_grow(cachep, flags | GFP_THISNODE, cpu_to_node(*this_cpu), NULL, this_cpu);
 
 		/* cache_grow can reenable interrupts, then ac could change. */
-		ac = cpu_cache_get(cachep);
+		ac = cpu_cache_get(cachep, *this_cpu);
 		if (!x && ac->avail == 0)	/* no objects in sight? abort */
 			return NULL;
 
@@ -3103,26 +3283,27 @@ static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags)
 	return should_failslab(obj_size(cachep), flags, cachep->flags);
 }
 
-static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+static inline void *
+____cache_alloc(struct kmem_cache *cachep, gfp_t flags, int *this_cpu)
 {
 	void *objp;
 	struct array_cache *ac;
 
 	check_irq_off();
 
-	ac = cpu_cache_get(cachep);
+	ac = cpu_cache_get(cachep, *this_cpu);
 	if (likely(ac->avail)) {
 		STATS_INC_ALLOCHIT(cachep);
 		ac->touched = 1;
 		objp = ac->entry[--ac->avail];
 	} else {
 		STATS_INC_ALLOCMISS(cachep);
-		objp = cache_alloc_refill(cachep, flags);
+		objp = cache_alloc_refill(cachep, flags, this_cpu);
 		/*
 		 * the 'ac' may be updated by cache_alloc_refill(),
 		 * and kmemleak_erase() requires its correct value.
 		 */
-		ac = cpu_cache_get(cachep);
+		ac = cpu_cache_get(cachep, *this_cpu);
 	}
 	/*
 	 * To avoid a false negative, if an object that is in one of the
@@ -3141,7 +3322,8 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
  * If we are in_interrupt, then process context, including cpusets and
  * mempolicy, may not apply and should not be used for allocation policy.
  */
-static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
+static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags,
+				int *this_cpu)
 {
 	int nid_alloc, nid_here;
 
@@ -3153,7 +3335,7 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
 	else if (current->mempolicy)
 		nid_alloc = slab_node(current->mempolicy);
 	if (nid_alloc != nid_here)
-		return ____cache_alloc_node(cachep, flags, nid_alloc);
+		return ____cache_alloc_node(cachep, flags, nid_alloc, this_cpu);
 	return NULL;
 }
 
@@ -3165,7 +3347,7 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
  * allocator to do its reclaim / fallback magic. We then insert the
  * slab into the proper nodelist and then allocate from it.
  */
-static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
+static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags, int *this_cpu)
 {
 	struct zonelist *zonelist;
 	gfp_t local_flags;
@@ -3193,7 +3375,8 @@ retry:
 			cache->nodelists[nid] &&
 			cache->nodelists[nid]->free_objects) {
 				obj = ____cache_alloc_node(cache,
-					flags | GFP_THISNODE, nid);
+					flags | GFP_THISNODE, nid,
+					this_cpu);
 				if (obj)
 					break;
 		}
@@ -3206,20 +3389,21 @@ retry:
 		 * We may trigger various forms of reclaim on the allowed
 		 * set and go into memory reserves if necessary.
 		 */
-		if (local_flags & __GFP_WAIT)
-			local_irq_enable();
+		slab_irq_enable_GFP_WAIT(local_flags, this_cpu);
+
 		kmem_flagcheck(cache, flags);
-		obj = kmem_getpages(cache, local_flags, numa_node_id());
-		if (local_flags & __GFP_WAIT)
-			local_irq_disable();
+		obj = kmem_getpages(cache, local_flags, cpu_to_node(*this_cpu));
+
+		slab_irq_disable_GFP_WAIT(local_flags, this_cpu);
+
 		if (obj) {
 			/*
 			 * Insert into the appropriate per node queues
 			 */
 			nid = page_to_nid(virt_to_page(obj));
-			if (cache_grow(cache, flags, nid, obj)) {
+			if (cache_grow(cache, flags, nid, obj, this_cpu)) {
 				obj = ____cache_alloc_node(cache,
-					flags | GFP_THISNODE, nid);
+					flags | GFP_THISNODE, nid, this_cpu);
 				if (!obj)
 					/*
 					 * Another processor may allocate the
@@ -3240,7 +3424,7 @@ retry:
  * A interface to enable slab creation on nodeid
  */
 static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
-				int nodeid)
+				int nodeid, int *this_cpu)
 {
 	struct list_head *entry;
 	struct slab *slabp;
@@ -3288,11 +3472,11 @@ retry:
 
 must_grow:
 	spin_unlock(&l3->list_lock);
-	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
+	x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL, this_cpu);
 	if (x)
 		goto retry;
 
-	return fallback_alloc(cachep, flags);
+	return fallback_alloc(cachep, flags, this_cpu);
 
 done:
 	return obj;
@@ -3315,6 +3499,7 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 		   void *caller)
 {
 	unsigned long save_flags;
+	int this_cpu, this_node;
 	void *ptr;
 
 	flags &= gfp_allowed_mask;
@@ -3325,32 +3510,33 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 		return NULL;
 
 	cache_alloc_debugcheck_before(cachep, flags);
-	local_irq_save(save_flags);
+	slab_irq_save(save_flags, this_cpu);
 
+	this_node = cpu_to_node(this_cpu);
 	if (nodeid == -1)
-		nodeid = numa_node_id();
+		nodeid = this_node;
 
 	if (unlikely(!cachep->nodelists[nodeid])) {
 		/* Node not bootstrapped yet */
-		ptr = fallback_alloc(cachep, flags);
+		ptr = fallback_alloc(cachep, flags, &this_cpu);
 		goto out;
 	}
 
-	if (nodeid == numa_node_id()) {
+	if (nodeid == this_node) {
 		/*
 		 * Use the locally cached objects if possible.
 		 * However ____cache_alloc does not allow fallback
 		 * to other nodes. It may fail while we still have
 		 * objects on other nodes available.
 		 */
-		ptr = ____cache_alloc(cachep, flags);
+		ptr = ____cache_alloc(cachep, flags, &this_cpu);
 		if (ptr)
 			goto out;
 	}
 	/* ___cache_alloc_node can fall back to other nodes */
-	ptr = ____cache_alloc_node(cachep, flags, nodeid);
+	ptr = ____cache_alloc_node(cachep, flags, nodeid, &this_cpu);
   out:
-	local_irq_restore(save_flags);
+	slab_irq_restore(save_flags, this_cpu);
 	ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
 	kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags,
 				 flags);
@@ -3365,33 +3551,33 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 }
 
 static __always_inline void *
-__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
+__do_cache_alloc(struct kmem_cache *cache, gfp_t flags, int *this_cpu)
 {
 	void *objp;
 
 	if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
-		objp = alternate_node_alloc(cache, flags);
+		objp = alternate_node_alloc(cache, flags, this_cpu);
 		if (objp)
 			goto out;
 	}
-	objp = ____cache_alloc(cache, flags);
 
+	objp = ____cache_alloc(cache, flags, this_cpu);
 	/*
 	 * We may just have run out of memory on the local node.
 	 * ____cache_alloc_node() knows how to locate memory on other nodes
 	 */
- 	if (!objp)
- 		objp = ____cache_alloc_node(cache, flags, numa_node_id());
-
+	if (!objp)
+		objp = ____cache_alloc_node(cache, flags,
+					    cpu_to_node(*this_cpu), this_cpu);
   out:
 	return objp;
 }
 #else
 
 static __always_inline void *
-__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags, int *this_cpu)
 {
-	return ____cache_alloc(cachep, flags);
+	return ____cache_alloc(cachep, flags, this_cpu);
 }
 
 #endif /* CONFIG_NUMA */
@@ -3400,6 +3586,7 @@ static __always_inline void *
 __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
 {
 	unsigned long save_flags;
+	int this_cpu;
 	void *objp;
 
 	flags &= gfp_allowed_mask;
@@ -3410,9 +3597,9 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
 		return NULL;
 
 	cache_alloc_debugcheck_before(cachep, flags);
-	local_irq_save(save_flags);
-	objp = __do_cache_alloc(cachep, flags);
-	local_irq_restore(save_flags);
+	slab_irq_save(save_flags, this_cpu);
+	objp = __do_cache_alloc(cachep, flags, &this_cpu);
+	slab_irq_restore(save_flags, this_cpu);
 	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
 	kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags,
 				 flags);
@@ -3431,7 +3618,7 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
  * Caller needs to acquire correct kmem_list's list_lock
  */
 static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
-		       int node)
+		       int node, int *this_cpu)
 {
 	int i;
 	struct kmem_list3 *l3;
@@ -3460,7 +3647,7 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 				 * a different cache, refer to comments before
 				 * alloc_slabmgmt.
 				 */
-				slab_destroy(cachep, slabp);
+				slab_destroy(cachep, slabp, this_cpu);
 			} else {
 				list_add(&slabp->list, &l3->slabs_free);
 			}
@@ -3474,11 +3661,12 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 	}
 }
 
-static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
+static void
+cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu)
 {
 	int batchcount;
 	struct kmem_list3 *l3;
-	int node = numa_node_id();
+	int node = cpu_to_node(*this_cpu);
 
 	batchcount = ac->batchcount;
 #if DEBUG
@@ -3500,7 +3688,7 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
 		}
 	}
 
-	free_block(cachep, ac->entry, batchcount, node);
+	free_block(cachep, ac->entry, batchcount, node, this_cpu);
 free_done:
 #if STATS
 	{
@@ -3529,9 +3717,9 @@ free_done:
  * Release an obj back to its cache. If the obj has a constructed state, it must
  * be in this state _before_ it is released.  Called with disabled ints.
  */
-static inline void __cache_free(struct kmem_cache *cachep, void *objp)
+static void __cache_free(struct kmem_cache *cachep, void *objp, int *this_cpu)
 {
-	struct array_cache *ac = cpu_cache_get(cachep);
+	struct array_cache *ac = cpu_cache_get(cachep, *this_cpu);
 
 	check_irq_off();
 	kmemleak_free_recursive(objp, cachep->flags);
@@ -3546,7 +3734,7 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp)
 	 * variable to skip the call, which is mostly likely to be present in
 	 * the cache.
 	 */
-	if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
+	if (nr_online_nodes > 1 && cache_free_alien(cachep, objp, this_cpu))
 		return;
 
 	if (likely(ac->avail < ac->limit)) {
@@ -3555,7 +3743,7 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp)
 		return;
 	} else {
 		STATS_INC_FREEMISS(cachep);
-		cache_flusharray(cachep, ac);
+		cache_flusharray(cachep, ac, this_cpu);
 		ac->entry[ac->avail++] = objp;
 	}
 }
@@ -3754,13 +3942,14 @@ EXPORT_SYMBOL(__kmalloc);
 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
 {
 	unsigned long flags;
+	int this_cpu;
 
-	local_irq_save(flags);
+	slab_irq_save(flags, this_cpu);
 	debug_check_no_locks_freed(objp, obj_size(cachep));
 	if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
 		debug_check_no_obj_freed(objp, obj_size(cachep));
-	__cache_free(cachep, objp);
-	local_irq_restore(flags);
+	__cache_free(cachep, objp, &this_cpu);
+	slab_irq_restore(flags, this_cpu);
 
 	trace_kmem_cache_free(_RET_IP_, objp);
 }
@@ -3779,18 +3968,19 @@ void kfree(const void *objp)
 {
 	struct kmem_cache *c;
 	unsigned long flags;
+	int this_cpu;
 
 	trace_kfree(_RET_IP_, objp);
 
 	if (unlikely(ZERO_OR_NULL_PTR(objp)))
 		return;
-	local_irq_save(flags);
+	slab_irq_save(flags, this_cpu);
 	kfree_debugcheck(objp);
 	c = virt_to_cache(objp);
 	debug_check_no_locks_freed(objp, obj_size(c));
 	debug_check_no_obj_freed(objp, obj_size(c));
-	__cache_free(c, (void *)objp);
-	local_irq_restore(flags);
+	__cache_free(c, (void *)objp, &this_cpu);
+	slab_irq_restore(flags, this_cpu);
 }
 EXPORT_SYMBOL(kfree);
 
@@ -3811,7 +4001,7 @@ EXPORT_SYMBOL_GPL(kmem_cache_name);
  */
 static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
 {
-	int node;
+	int node, this_cpu;
 	struct kmem_list3 *l3;
 	struct array_cache *new_shared;
 	struct array_cache **new_alien = NULL;
@@ -3839,11 +4029,11 @@ static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
 		if (l3) {
 			struct array_cache *shared = l3->shared;
 
-			spin_lock_irq(&l3->list_lock);
+			slab_spin_lock_irq(&l3->list_lock, this_cpu);
 
 			if (shared)
 				free_block(cachep, shared->entry,
-						shared->avail, node);
+					   shared->avail, node, &this_cpu);
 
 			l3->shared = new_shared;
 			if (!l3->alien) {
@@ -3852,7 +4042,7 @@ static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
 			}
 			l3->free_limit = (1 + nr_cpus_node(node)) *
 					cachep->batchcount + cachep->num;
-			spin_unlock_irq(&l3->list_lock);
+			slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 			kfree(shared);
 			free_alien_cache(new_alien);
 			continue;
@@ -3899,24 +4089,36 @@ struct ccupdate_struct {
 	struct array_cache *new[NR_CPUS];
 };
 
-static void do_ccupdate_local(void *info)
+static void __do_ccupdate_local(void *info, int this_cpu)
 {
 	struct ccupdate_struct *new = info;
 	struct array_cache *old;
 
 	check_irq_off();
-	old = cpu_cache_get(new->cachep);
+	old = cpu_cache_get(new->cachep, this_cpu);
 
-	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
-	new->new[smp_processor_id()] = old;
+	new->cachep->array[this_cpu] = new->new[this_cpu];
+	new->new[this_cpu] = old;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_ccupdate_local(void *arg, int this_cpu)
+{
+	__do_ccupdate_local(arg, this_cpu);
+}
+#else
+static void do_ccupdate_local(void *arg)
+{
+	__do_ccupdate_local(arg, smp_processor_id());
+}
+#endif
+
 /* Always called with the cache_chain_mutex held */
 static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
 				int batchcount, int shared, gfp_t gfp)
 {
 	struct ccupdate_struct *new;
-	int i;
+	int i, this_cpu;
 
 	new = kzalloc(sizeof(*new), gfp);
 	if (!new)
@@ -3934,7 +4136,7 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
 	}
 	new->cachep = cachep;
 
-	on_each_cpu(do_ccupdate_local, (void *)new, 1);
+	slab_on_each_cpu(do_ccupdate_local, (void *)new);
 
 	check_irq_on();
 	cachep->batchcount = batchcount;
@@ -3945,9 +4147,12 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
 		struct array_cache *ccold = new->new[i];
 		if (!ccold)
 			continue;
-		spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
-		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
-		spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
+		slab_spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock,
+				   this_cpu);
+		free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i),
+			   &this_cpu);
+		slab_spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock,
+				     this_cpu);
 		kfree(ccold);
 	}
 	kfree(new);
@@ -4012,29 +4217,31 @@ static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
  * Drain an array if it contains any elements taking the l3 lock only if
  * necessary. Note that the l3 listlock also protects the array_cache
  * if drain_array() is used on the shared array.
+ * returns non-zero if some work is done
  */
-void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
-			 struct array_cache *ac, int force, int node)
+int drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
+		 struct array_cache *ac, int force, int node)
 {
-	int tofree;
+	int tofree, this_cpu;
 
 	if (!ac || !ac->avail)
-		return;
+		return 0;
 	if (ac->touched && !force) {
 		ac->touched = 0;
 	} else {
-		spin_lock_irq(&l3->list_lock);
+		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 		if (ac->avail) {
 			tofree = force ? ac->avail : (ac->limit + 4) / 5;
 			if (tofree > ac->avail)
 				tofree = (ac->avail + 1) / 2;
-			free_block(cachep, ac->entry, tofree, node);
+			free_block(cachep, ac->entry, tofree, node, &this_cpu);
 			ac->avail -= tofree;
 			memmove(ac->entry, &(ac->entry[tofree]),
 				sizeof(void *) * ac->avail);
 		}
-		spin_unlock_irq(&l3->list_lock);
+		slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 	}
+	return 1;
 }
 
 /**
@@ -4051,10 +4258,11 @@ void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
  */
 static void cache_reap(struct work_struct *w)
 {
+	int this_cpu = raw_smp_processor_id(), node = cpu_to_node(this_cpu);
 	struct kmem_cache *searchp;
 	struct kmem_list3 *l3;
-	int node = numa_node_id();
 	struct delayed_work *work = to_delayed_work(w);
+	int work_done = 0;
 
 	if (!mutex_trylock(&cache_chain_mutex))
 		/* Give up. Setup the next iteration. */
@@ -4070,9 +4278,12 @@ static void cache_reap(struct work_struct *w)
 		 */
 		l3 = searchp->nodelists[node];
 
-		reap_alien(searchp, l3);
+		work_done += reap_alien(searchp, l3, &this_cpu);
+
+		node = cpu_to_node(this_cpu);
 
-		drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
+		work_done += drain_array(searchp, l3,
+			    cpu_cache_get(searchp, this_cpu), 0, node);
 
 		/*
 		 * These are racy checks but it does not matter
@@ -4083,7 +4294,7 @@ static void cache_reap(struct work_struct *w)
 
 		l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
 
-		drain_array(searchp, l3, l3->shared, 0, node);
+		work_done += drain_array(searchp, l3, l3->shared, 0, node);
 
 		if (l3->free_touched)
 			l3->free_touched = 0;
@@ -4102,7 +4313,8 @@ next:
 	next_reap_node();
 out:
 	/* Set up the next iteration */
-	schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
+	schedule_delayed_work(work,
+		round_jiffies_relative((1+!work_done) * REAPTIMEOUT_CPUC));
 }
 
 #ifdef CONFIG_SLABINFO
@@ -4161,7 +4373,7 @@ static int s_show(struct seq_file *m, void *p)
 	unsigned long num_slabs, free_objects = 0, shared_avail = 0;
 	const char *name;
 	char *error = NULL;
-	int node;
+	int this_cpu, node;
 	struct kmem_list3 *l3;
 
 	active_objs = 0;
@@ -4172,7 +4384,7 @@ static int s_show(struct seq_file *m, void *p)
 			continue;
 
 		check_irq_on();
-		spin_lock_irq(&l3->list_lock);
+		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 
 		list_for_each_entry(slabp, &l3->slabs_full, list) {
 			if (slabp->inuse != cachep->num && !error)
@@ -4197,7 +4409,7 @@ static int s_show(struct seq_file *m, void *p)
 		if (l3->shared)
 			shared_avail += l3->shared->avail;
 
-		spin_unlock_irq(&l3->list_lock);
+		slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 	}
 	num_slabs += active_slabs;
 	num_objs = num_slabs * cachep->num;
@@ -4407,7 +4619,7 @@ static int leaks_show(struct seq_file *m, void *p)
 	struct kmem_list3 *l3;
 	const char *name;
 	unsigned long *n = m->private;
-	int node;
+	int node, this_cpu;
 	int i;
 
 	if (!(cachep->flags & SLAB_STORE_USER))
@@ -4425,13 +4637,13 @@ static int leaks_show(struct seq_file *m, void *p)
 			continue;
 
 		check_irq_on();
-		spin_lock_irq(&l3->list_lock);
+		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 
 		list_for_each_entry(slabp, &l3->slabs_full, list)
 			handle_slab(n, cachep, slabp);
 		list_for_each_entry(slabp, &l3->slabs_partial, list)
 			handle_slab(n, cachep, slabp);
-		spin_unlock_irq(&l3->list_lock);
+		slab_spin_unlock_irq(&l3->list_lock, this_cpu);
 	}
 	name = cachep->name;
 	if (n[0] == n[1]) {
-- 
1.7.1.1