From: Ravikiran G Thirumalai Date: Sun, 5 Feb 2006 07:27:58 +0000 (-0800) Subject: [PATCH] NUMA slab locking fixes: irq disabling from cahep->spinlock to l3 lock X-Git-Tag: v2.6.16-rc3~155 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ca3b9b91735316f0ec7f01976f85842e0bfe5c6e;p=linux-2.6 [PATCH] NUMA slab locking fixes: irq disabling from cahep->spinlock to l3 lock Earlier, we had to disable on chip interrupts while taking the cachep->spinlock because, at cache_grow, on every addition of a slab to a slab cache, we incremented colour_next which was protected by the cachep->spinlock, and cache_grow could occur at interrupt context. Since, now we protect the per-node colour_next with the node's list_lock, we do not need to disable on chip interrupts while taking the per-cache spinlock, but we just need to disable interrupts when taking the per-node kmem_list3 list_lock. Signed-off-by: Alok N Kataria Signed-off-by: Ravikiran Thirumalai Signed-off-by: Shai Fultheim Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/slab.c b/mm/slab.c index 2317096166..d3f68543f9 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -987,7 +987,7 @@ static int __devinit cpuup_callback(struct notifier_block *nfb, cpumask_t mask; mask = node_to_cpumask(node); - spin_lock_irq(&cachep->spinlock); + spin_lock(&cachep->spinlock); /* cpu is dead; no one can alloc from it. */ nc = cachep->array[cpu]; cachep->array[cpu] = NULL; @@ -996,7 +996,7 @@ static int __devinit cpuup_callback(struct notifier_block *nfb, if (!l3) goto unlock_cache; - spin_lock(&l3->list_lock); + spin_lock_irq(&l3->list_lock); /* Free limit for this kmem_list3 */ l3->free_limit -= cachep->batchcount; @@ -1004,7 +1004,7 @@ static int __devinit cpuup_callback(struct notifier_block *nfb, free_block(cachep, nc->entry, nc->avail, node); if (!cpus_empty(mask)) { - spin_unlock(&l3->list_lock); + spin_unlock_irq(&l3->list_lock); goto unlock_cache; } @@ -1023,13 +1023,13 @@ static int __devinit cpuup_callback(struct notifier_block *nfb, /* free slabs belonging to this node */ if (__node_shrink(cachep, node)) { cachep->nodelists[node] = NULL; - spin_unlock(&l3->list_lock); + spin_unlock_irq(&l3->list_lock); kfree(l3); } else { - spin_unlock(&l3->list_lock); + spin_unlock_irq(&l3->list_lock); } unlock_cache: - spin_unlock_irq(&cachep->spinlock); + spin_unlock(&cachep->spinlock); kfree(nc); } mutex_unlock(&cache_chain_mutex); @@ -2011,18 +2011,18 @@ static void drain_cpu_caches(struct kmem_cache *cachep) smp_call_function_all_cpus(do_drain, cachep); check_irq_on(); - spin_lock_irq(&cachep->spinlock); + spin_lock(&cachep->spinlock); for_each_online_node(node) { l3 = cachep->nodelists[node]; if (l3) { - spin_lock(&l3->list_lock); + spin_lock_irq(&l3->list_lock); drain_array_locked(cachep, l3->shared, 1, node); - spin_unlock(&l3->list_lock); + spin_unlock_irq(&l3->list_lock); if (l3->alien) drain_alien_cache(cachep, l3); } } - spin_unlock_irq(&cachep->spinlock); + spin_unlock(&cachep->spinlock); } static int __node_shrink(struct kmem_cache *cachep, int node) @@ -2338,7 +2338,6 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid) offset *= cachep->colour_off; - check_irq_off(); if (local_flags & __GFP_WAIT) local_irq_enable(); @@ -2725,6 +2724,7 @@ static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int node BUG_ON(!l3); retry: + check_irq_off(); spin_lock(&l3->list_lock); entry = l3->slabs_partial.next; if (entry == &l3->slabs_partial) { @@ -3304,11 +3304,11 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount smp_call_function_all_cpus(do_ccupdate_local, (void *)&new); check_irq_on(); - spin_lock_irq(&cachep->spinlock); + spin_lock(&cachep->spinlock); cachep->batchcount = batchcount; cachep->limit = limit; cachep->shared = shared; - spin_unlock_irq(&cachep->spinlock); + spin_unlock(&cachep->spinlock); for_each_online_cpu(i) { struct array_cache *ccold = new.new[i]; @@ -3564,8 +3564,7 @@ static int s_show(struct seq_file *m, void *p) int node; struct kmem_list3 *l3; - check_irq_on(); - spin_lock_irq(&cachep->spinlock); + spin_lock(&cachep->spinlock); active_objs = 0; num_slabs = 0; for_each_online_node(node) { @@ -3573,7 +3572,8 @@ static int s_show(struct seq_file *m, void *p) if (!l3) continue; - spin_lock(&l3->list_lock); + check_irq_on(); + spin_lock_irq(&l3->list_lock); list_for_each(q, &l3->slabs_full) { slabp = list_entry(q, struct slab, list); @@ -3600,7 +3600,7 @@ static int s_show(struct seq_file *m, void *p) free_objects += l3->free_objects; shared_avail += l3->shared->avail; - spin_unlock(&l3->list_lock); + spin_unlock_irq(&l3->list_lock); } num_slabs += active_slabs; num_objs = num_slabs * cachep->num; @@ -3644,7 +3644,7 @@ static int s_show(struct seq_file *m, void *p) } #endif seq_putc(m, '\n'); - spin_unlock_irq(&cachep->spinlock); + spin_unlock(&cachep->spinlock); return 0; }