From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: NUMA page allocation from next Node
Date: Mon, 1 Nov 2010 19:00:59 +0100
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To: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Tharindu Rukshan Bamunuarachchi <btharindu@gmail.com>, Tim Pepper <lnxninja@linux.vnet.ibm.com>, linux-numa@vger.kernel.org

> Because the SLIT on the IBM platform has distances > 20.  Looks like IBM
> is populating the SLIT on those platforms with "real" values.  The HP
> bios is not supplying a slit, letting the remote distances default to
> 20.  That is the threshold for setting zone_reclaim_mode.  A patch was
> submitted recently to bump the threshold to ~30.  Now that vendors are
> starting to populate the SLIT with values > 20, we've begun to see the
> behavior that you experienced. 

I think it's intentional by the vendors: they use it a way to make
Linux behave like they want.

-Andi