On Fri, Oct 22, 2010 at 09:06:48AM -0500, Christoph Lameter wrote: > On Fri, 22 Oct 2010, KOSAKI Motohiro wrote: > > > I think this series has the same target with Nick's per-zone shrinker. > > So, Do you dislike Nick's approach? can you please elaborate your intention? > > Sorry. I have not seen Nicks approach. Latest was posted to linux-mm a few days ago. > The per zone approach seems to be at variance with how objects are tracked > at the slab layer. There is no per zone accounting there. So attempts to > do expiration of caches etc at that layer would not work right. It is not a "slab shrinker", despite the convention to call it that. It is a "did you allocate memory that you might be nice and be able to give some back if we have a memory shortage" callback. The pagecache is all totally driven (calculated, accounted, scanned) per-zone, and pagecache reclaim progress drives shrinker reclaim. Making it per-node adds an unneccesary complicated coupling. If a particular subsystem only tracks things on a per-node basis, they can easily to zone_to_nid(zone) in the callback or something like that. But really, doing LRUs in the zones makes much more sense than in the nodes. Slab layer doesn't have huge amounts of critical reclaimable objects like dcache or inode layers, so it is probably fine just to kick off slab reapers for the node when it gets a request. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>