Re: [RFC][PATCH v2] slub: Keep page and object in sync in slab_alloc_node()
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2013-01-18 15:29:56
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linux-mm, lkml
On Fri, 2013-01-18 at 13:42 +0900, Joonsoo Kim wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 9db4825..b54dffa 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h@@ -46,6 +46,9 @@ enum stat_item { struct kmem_cache_cpu { void **freelist; /* Pointer to next available object */ unsigned long tid; /* Globally unique transaction id */ +#ifdef CONFIG_NUMA + int node;
Note, you put an int between a long and a pointer, which will waste 4 bytes on 64bit machines.
+#endif struct page *page; /* The slab from which we are allocating */ struct page *partial; /* Partially allocated frozen slabs */ #ifdef CONFIG_SLUB_STATS
quoted hunk ↗ jump to hunk
@@ -2038,10 +2049,10 @@ static void flush_all(struct kmem_cache *s) * Check if the objects in a per cpu structure fit numa * locality expectations. */ -static inline int node_match(struct page *page, int node) +static inline int node_match(struct kmem_cache_cpu *c, int node) { #ifdef CONFIG_NUMA - if (node != NUMA_NO_NODE && page_to_nid(page) != node) + if (node != NUMA_NO_NODE && c->node != node)
We still have the issue of cpu fetching c->node before c->tid and c->freelist. I still believe the only solution is to prevent the task from migrating via a preempt disable. -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>