Re: [resend][PATCH] mm: increase RECLAIM_DISTANCE to 30

From: Christoph Lameter
Date: Fri Oct 08 2010 - 14:06:32 EST


On Fri, 8 Oct 2010, Balbir Singh wrote:

> * Christoph Lameter <cl@xxxxxxxxx> [2010-10-08 10:45:16]:
>
> > On Fri, 8 Oct 2010, Balbir Singh wrote:
> >
> > > I am not sure if this makes sense, since RECLAIM_DISTANCE is supposed
> > > to be a hardware parameter. Could you please help clarify what the
> > > access latency of a node with RECLAIM_DISTANCE 20 to that of a node
> > > with RECLAIM_DISTANCE 30 is? Has the hardware definition of reclaim
> > > distance changed?
> >
> > 10 is the local distance. So 30 should be 3x the latency that a local
> > access takes.
> >
>
> Does this patch then imply that we should do zone_reclaim only for 3x
> nodes and not 2x nodes as we did earlier.

It implies that zone reclaim is going to be automatically enabled if the
maximum latency to the memory farthest away is 3 times or more that of a
local memory access.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/