[libvirt] [PATCH] Make nodeGetInfo report the correct number of NUMA nodes.

[Luiz Capitulino]

 Hi Chris,

On Thu, 11 Mar 2010 18:00:56 -0500
Chris Lalancette <clalance at redhat.com> wrote:

> The nodeGetInfo code was always assuming that machine had a
> single NUMA node, which is not correct.  The good news is that
> libnuma gives us this information pretty easily, so let's
> properly report it.
> 
> NOTE: With recent hardware starting to support CPU hot-add
> and hot-remove, both this code and the nodeCapsInitNUMA()
> code are quickly going to become obsolete.  We'll have to
> think of a more dynamic solution for dealing with NUMA
> nodes and CPUs that can come and go at will.
> 
> Signed-off-by: Chris Lalancette <clalance at redhat.com>
> ---
>  src/nodeinfo.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/src/nodeinfo.c b/src/nodeinfo.c
> index 0748602..8d7e055 100644
> --- a/src/nodeinfo.c
> +++ b/src/nodeinfo.c
> @@ -159,7 +159,11 @@ int linuxNodeInfoCPUPopulate(virConnectPtr conn, FILE *cpuinfo,
>  
>      nodeinfo->cpus = 0;
>      nodeinfo->mhz = 0;
> -    nodeinfo->nodes = nodeinfo->cores = 1;
> +    nodeinfo->cores = 1;
> +    if (numa_available() < 0)
> +        nodeinfo->nodes = 1;
> +    else
> +        nodeinfo->nodes = numa_max_node() + 1;
>  
>      /* NB: It is impossible to fill our nodes, since cpuinfo
>       * has no knowledge of NUMA nodes */

 This commit breaks the build for me with the following message:

"""
cc1: warnings being treated as errors
nodeinfo.c: In function 'linuxNodeInfoCPUPopulate':
nodeinfo.c:163: error: implicit declaration of function 'numa_available'
nodeinfo.c:163: error: nested extern declaration of 'numa_available'
nodeinfo.c:166: error: implicit declaration of function 'numa_max_node'
nodeinfo.c:166: error: nested extern declaration of 'numa_max_node'
make[3]: *** [libvirt_driver_la-nodeinfo.lo] Error 1
make[3]: *** Waiting for unfinished jobs....
...
"""

 The code in this file that uses the same functions seems to be protected
by the HAVE_NUMACTL macro.