Re: [patch 1/3] slob: rework freelist handling

Matt Mackall
2007-05-23T18:32:24Z

On Wed, May 23, 2007 at 10:03:34AM -0700, Christoph Lameter wrote:
> On Wed, 23 May 2007, Nick Piggin wrote:
>
> > On Tue, May 22, 2007 at 11:28:18PM -0700, Christoph Lameter wrote:
> > > On Wed, 23 May 2007, Nick Piggin wrote:
> > >
> > > > If you want to do a memory consumption shootout with SLOB, you need
> > > > all the help you can get ;)
> > >
> > > No way. And first you'd have to make SLOB functional. Among other
> > > things it does not support slab reclaim.
> >
> > What do you mean by slab reclaim? SLOB doesn't have slabs and it
> > never keeps around unused pages so I can't see how it would be able
> > to do anything more useful. SLOB is fully functional here, on my 4GB
> > desktop system, even.
>
> SLOB does not f.e. handle the SLAB ZVCs. The VM will think there is no
> slab use and never shrink the slabs.

You keep saying something like this but I'm never quite clear what you
mean. There are no slabs so reclaiming unused slabs is a non-issue.
Things like shrinking the dcache should work:

__alloc_pages
try_to_free_pages
shrink_slab
shrink_dcache_memory

I don't see any checks of ZVCs interfering with that path.

--
Mathematics is the supreme nostalgia of our time.