Re: [PATCH 3/3] page-allocator: Move pcp static fields for high and batch off-pcp and onto the zone

[Mel Gorman <mel@csn.ul.ie>]

On Tue, Aug 18, 2009 at 01:47:52PM +0200, Nick Piggin wrote:
> On Tue, Aug 18, 2009 at 12:16:02PM +0100, Mel Gorman wrote:
> > Having multiple lists per PCPU increased the size of the per-pcpu
> > structure. Two of the fields, high and batch, do not change within a
> > zone making that information redundant. This patch moves those fields
> > off the PCP and onto the zone to reduce the size of the PCPU.
> 
> Hmm.. I did have some patches a long long time ago that among other
> things made the lists larger for the local node only....
> 

To reduce the remote node lists, one could look at applying some fixed factor
to the high value or basing remote lists on some percentage of high.

> But I guess if something like that is ever shown to be a good idea
> then we can go back to the old scheme. So yeah this seems OK.
> 

Thanks.

> > 
> > Signed-off-by: Mel Gorman <mel@csn.ul.ie>
> > ---
> >  include/linux/mmzone.h |    9 +++++----
> >  mm/page_alloc.c        |   47 +++++++++++++++++++++++++----------------------
> >  mm/vmstat.c            |    4 ++--
> >  3 files changed, 32 insertions(+), 28 deletions(-)
> > 
> > <SNIP>

-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab