Re: [PATCH] CPU/mem hotplug: enable CPUs online before local memory online

Re: [PATCH] CPU/mem hotplug: enable CPUs online before local memory online

[Andrew Morton]

On Fri, 07 May 2010 13:50:52 +0800
minskey guo <chaohong_guo@linux.intel.com> wrote:

> This patch enables users to online CPUs even if the CPUs belongs to
> a numa node which doesn't have onlined local memory.
> 
> The zonlists(pg_data_t.node_zonelists[]) of a numa node are created
> either in system boot/init period, or at the time of local memory
> online.  For a numa node without onlined local memory, its zonelists
> are not initialized at present. As a result, any memory allocation
> operations executed by CPUs within this node will fail. In fact, an
> out-of-memory error is triggered when attempt to online CPUs before
> memory comes to online.
> 
> This patch tries to create zonelists for such numa nodes, so that
> the memory allocation for this node can be fallback'ed to other
> nodes.

I had a horrible time extracting a usable patch from this email. 
Please don't send two copies of a patch in a single email.  One version
was space-stuffed and the other had text/plain mimetype.  text/plain
attachents are OK.  Plain old inlined text is preferred, but first
email yourself a test patch to check that it isn't getting mangled. 
Make sure that the patch has lines longer than 100 chars to check for
wordwrapping.


I removed the unneeded EXPORT_SYMBOL_GPL(mem_online_node);