Re: [RFC][PATCH 2/2] perzone slab LRUs

Martin J. Bligh wrote:

quoted

Oops, forgot to CC linux-mm.

Nick Piggin wrote:

quoted

This patch is only intended for comments.

This implements (crappy?) infrastructure for per-zone slab LRUs for
reclaimable slabs, and moves dcache.c over to use that.

The global unused list is retained to reduce intrusiveness, and another
per-zone LRU list is added (which are still protected with the global 
dcache
lock). This is an attempt to make slab scanning more robust on highmem and
NUMA systems.

Do we have slab that goes in highmem anywhere? I thought not .... 64 bit
NUMA makes a lot of sense though.

I don't think so, but it still (I think) allows a general slab pressure 
forumula
for highmem and muliple ZONE_NORMAL NUMA that doesn't blow up like our 
current
one can.

The per-zone lists I'd say would have to help somewhat on the 
performance side of
things as far as not taking remote cache misses during scanning. It 
should also
mean that a low memory node will not globally shrink masses of slab from 
nodes that
have plenty of memory.

As far as the dependant inodes problem goes - it could be a significant 
problem,
and I think would need to be solved before perzone slab LRUs are a 
viable option.
The most simplistic way I can see to solve it is: if we scan an inode 
that is pinned
by dentries, scan its pinning dentries instead.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>