Re: + bootmem-node-setup-agnostic-free_bootmem.patch added to -mm tree

[Johannes Weiner <hannes@saeurebad.de>]

Hi,

"Yinghai Lu" <yhlu.kernel@gmail.com> writes:

> On Tue, Apr 15, 2008 at 2:14 PM, Johannes Weiner <hannes@saeurebad.de> wrote:
>> Hi,
>>
>>  "Yinghai Lu" <yhlu.kernel@gmail.com> writes:
>>
>>
>> >>  > 2. intel cross node box: node0: 0g-2g, 4g-6g, node1: 2g-4g, 6g-8g. i
>>  >>  > don't think they have two bdata struct for every node.
>>  >>
>>  >>  How do the bdata structures represent this setup right now?  Are you
>>  >>  sure that there is not a node descriptor for every contiguous region?
>>  >
>>  > http://lkml.org/lkml/2008/3/25/233
>>  >
>>  > Subject       [patch] srat, x86_64: Add support for nodes spanning other nodes
>>  >
>>  > For example, If the physical address layout on a two node system with 8 GB
>>  > memory is something like:
>>  > node 0: 0-2GB, 4-6GB
>>  > node 1: 2-4GB, 6-8GB
>>  >
>>  > Current kernels fail to boot/detect this NUMA topology.
>>  >
>>  > ACPI SRAT tables can expose such a topology which needs to be supported.
>>  >
>>  > Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
>>
>>  As I understood the code (more guessing than understanding), it breaks
>>  down these physical nodes into contiguous logical memory blocks which
>>  then get represented by having a node descriptor for each of them.  Can
>>  you confirm that?
>
> Not sure, on x86_64 one node should have one bdata only.
> execpt suresh update that to make one node have two bdata.

We are just guessing around here.

My understanding is that right now we have contigous physical nodes
represented by a node descriptor each and with Suresh's patch we have
each contigous block represented by its own node descriptor.

So in this setup

	node 0: 0-2GB, 4-6GB
	node 1: 2-4GB, 6-8GB

we have 4 node descriptors [0-2], [2-4], [4-6], [6-8]?

Can someone please ack/nak this?

	Hannes