Re: No, really, stop trying to delete slab until you've finished making slub perform as well

From: KOSAKI Motohiro
Date: Wed Aug 20 2008 - 07:48:20 EST


> KOSAKI Motohiro wrote:
>
> > IOW, My box didn't happend performance regression.
> > but I think it isn't typical.
>
> Well that is typical for small NUMA system. Maybe this patch will fix it for
> now? Large systems can be tuned by setting the ratio lower.
>
>
> Subject: slub/NUMA: Disable remote node defragmentation by default
>
> Switch remote node defragmentation off by default. The current settings can
> cause excessive node local allocations with hackbench. (Note that this feature
> is not related to slab defragmentation).

OK.
I confirmed this patch works well.

Tested-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>


>
> Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
>
> ---
> mm/slub.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Index: linux-2.6/mm/slub.c
> ===================================================================
> --- linux-2.6.orig/mm/slub.c 2008-08-19 06:45:54.732348449 -0700
> +++ linux-2.6/mm/slub.c 2008-08-19 06:46:12.442348249 -0700
> @@ -2312,7 +2312,7 @@ static int kmem_cache_open(struct kmem_c
>
> s->refcount = 1;
> #ifdef CONFIG_NUMA
> - s->remote_node_defrag_ratio = 100;
> + s->remote_node_defrag_ratio = 1000;
> #endif
> if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
> goto error;
> @@ -4058,7 +4058,7 @@ static ssize_t remote_node_defrag_ratio_
> if (err)
> return err;
>
> - if (ratio < 100)
> + if (ratio <= 100)
> s->remote_node_defrag_ratio = ratio * 10;
>
> return length;



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/