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

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

> 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@jp.fujitsu.com>


> 
> Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
> 
> ---
>  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;