Re: 2.6.14-rc2-mm1 (Oops, possibly Netfilter related?)

[Rohit Seth <rohit.seth@intel.com>]

On Sun, 2005-10-02 at 14:31 -0700, Martin J. Bligh wrote:
> 
> --Paul Jackson <pj@sgi.com> wrote (on Sunday, October 02, 2005 10:13:19 -0700):
> 
> > Martin, responding to Andrew:
> >> > I've dropped that patch.  Joel Schopp is working on Mel Gorman's patches
> >> > which address fragmentation at this level.  If that code gets there then we
> >> > can take another look at
> >> > mm-try-to-allocate-higher-order-pages-in-rmqueue_bulk.patch.
> >> 
> >> Me no understand. We're going to deliberately cause fragmentation in order
> >> to defragment it again later ???
> > 
> > I thought that the patches of Mel Gorman and Joel Schopp were reducing
> > fragmentation, not causing it.
> 
> They were. but mm-try-to-allocate-higher-order-pages-in-rmqueue_bulk
> seems to be going in the opposite direction.

mm-try-to-allocate-higher-order-pages-in-rmqueue_bulk patch tries to
allocate more physical contiguous pages for pcp.  This would cause some
extra fragmentation at the higher orders but has the potential benefit
of spreading more uniformly across caches.  I agree though that for this
scheme to work nicely we should have the capability of draining the pcps
so that higher order requests can be serviced whenever possible.

-rohit