From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: David Rientjes <rientjes@google.com>
Cc: linuxppc-dev@ozlabs.org, Ankita Garg <ankita@in.ibm.com>,
linux-kernel@vger.kernel.org,
Balbir Singh <balbir@linux.vnet.ibm.com>
Subject: Re: [PATCH] Fix fake numa on ppc
Date: Wed, 02 Sep 2009 18:51:39 +1000 [thread overview]
Message-ID: <1251881499.14675.453.camel@pasglop> (raw)
In-Reply-To: <alpine.DEB.1.00.0909012259050.26930@chino.kir.corp.google.com>
On Tue, 2009-09-01 at 23:03 -0700, David Rientjes wrote:
> On Wed, 2 Sep 2009, Benjamin Herrenschmidt wrote:
>
> > Since I'm pretty sure there could be CPU less nodes just like there
> > could be memory-less nodes, it would be good if fake numa could
> > simulate them too :-)
> >
>
> You don't want to simulate cpu less nodes since they do have affinity to
> ranges of memory, you want to map each fake node to a cpumask including
> all cpus with affinity to its memory, map each cpu to one fake node (with
> memory) that it has physical affinity to, and then give all fake nodes
> local NUMA distance to those on the same physical node. Memoryless nodes
> take care of themselves since they rely purely on node_distance(), so the
> index into the slit for all fake nodes to those without memory will be the
> same.
Ok, makes sense, thanks.
Cheers,
Ben.
next prev parent reply other threads:[~2009-09-02 8:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-01 5:03 [PATCH] Fix fake numa on ppc Ankita Garg
2009-09-01 5:57 ` Balbir Singh
2009-09-01 9:24 ` Ankita Garg
2009-09-01 14:27 ` Balbir Singh
2009-09-02 5:36 ` Ankita Garg
2009-09-02 5:53 ` Benjamin Herrenschmidt
2009-09-02 6:03 ` David Rientjes
2009-09-02 8:51 ` Benjamin Herrenschmidt [this message]
2009-09-02 5:58 ` David Rientjes
2009-09-02 5:52 ` Benjamin Herrenschmidt
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