[slubllv7 14/17] slub: Add statistics for the case that the current slab does not match the node

[Christoph Lameter]

Slub reloads the per cpu slab if the page does not satisfy the NUMA condition. Track
those reloads since doing so has a performance impact.

Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>


---
 include/linux/slub_def.h |    1 +
 mm/slub.c                |    3 +++
 2 files changed, 4 insertions(+)

Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h	2011-05-31 14:27:07.332880140 -0500
+++ linux-2.6/include/linux/slub_def.h	2011-05-31 14:27:17.792880073 -0500
@@ -24,6 +24,7 @@ enum stat_item {
 	ALLOC_FROM_PARTIAL,	/* Cpu slab acquired from partial list */
 	ALLOC_SLAB,		/* Cpu slab acquired from page allocator */
 	ALLOC_REFILL,		/* Refill cpu slab from slab freelist */
+	ALLOC_NODE_MISMATCH,	/* Switching cpu slab */
 	FREE_SLAB,		/* Slab freed to the page allocator */
 	CPUSLAB_FLUSH,		/* Abandoning of the cpu slab */
 	DEACTIVATE_FULL,	/* Cpu slab was full when deactivated */
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-05-31 14:27:12.002880106 -0500
+++ linux-2.6/mm/slub.c	2011-05-31 14:27:17.792880073 -0500
@@ -1966,6 +1966,7 @@ static void *__slab_alloc(struct kmem_ca
 		goto new_slab;
 
 	if (unlikely(!node_match(c, node))) {
+		stat(s, ALLOC_NODE_MISMATCH);
 		deactivate_slab(s, c);
 		goto new_slab;
 	}
@@ -4675,6 +4676,7 @@ STAT_ATTR(FREE_REMOVE_PARTIAL, free_remo
 STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
 STAT_ATTR(ALLOC_SLAB, alloc_slab);
 STAT_ATTR(ALLOC_REFILL, alloc_refill);
+STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
 STAT_ATTR(FREE_SLAB, free_slab);
 STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
 STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
@@ -4734,6 +4736,7 @@ static struct attribute *slab_attrs[] =
 	&alloc_from_partial_attr.attr,
 	&alloc_slab_attr.attr,
 	&alloc_refill_attr.attr,
+	&alloc_node_mismatch_attr.attr,
 	&free_slab_attr.attr,
 	&cpuslab_flush_attr.attr,
 	&deactivate_full_attr.attr,

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