Re: [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once perpriority

[Mel Gorman]

On Wed, Apr 10, 2013 at 11:07:34AM +1000, Dave Chinner wrote:
> On Tue, Apr 09, 2013 at 12:13:59PM +0100, Mel Gorman wrote:
> > On Tue, Apr 09, 2013 at 03:53:25PM +0900, Joonsoo Kim wrote:
> > 
> > > I think that outside of zone loop is better place to run shrink_slab(),
> > > because shrink_slab() is not directly related to a specific zone.
> > > 
> > 
> > This is true and has been the case for a long time. The slab shrinkers
> > are not zone aware and it is complicated by the fact that slab usage can
> > indirectly pin memory on other zones.
> ......
> > > And this is a question not related to this patch.
> > > Why nr_slab is used here to decide zone->all_unreclaimable?
> > 
> > Slab is not directly associated with a slab but as reclaiming slab can
> > free memory from unpredictable zones we do not consider a zone to be
> > fully unreclaimable until we cannot shrink slab any more.
> 
> This is something the numa aware shrinkers will greatly help with -
> instead of being a global shrink it becomes a
> node-the-zone-belongs-to shrink, and so....
> 

Yes, 100% agreed.

-- 
Mel Gorman
SUSE Labs
--
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/