On Mon, Jun 02, 2014 at 02:15:59PM +0200, Michal Privoznik wrote:
The API gets a NUMA node and find distances to other nodes. The distances are returned in an array. If an item X within the array equals to value of zero, then there's no such node as X.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/libvirt_private.syms | 1 + src/util/virnuma.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ src/util/virnuma.h | 3 +++ 3 files changed, 54 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index cb635cd..6168f76 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1652,6 +1652,7 @@ virNodeSuspendGetTargetMask; virDomainNumatuneMemModeTypeFromString; virDomainNumatuneMemModeTypeToString; virNumaGetAutoPlacementAdvice; +virNumaGetDistances; virNumaGetMaxNode; virNumaGetNodeMemory; virNumaIsAvailable; diff --git a/src/util/virnuma.c b/src/util/virnuma.c index 1e099eb..68b2698 100644 --- a/src/util/virnuma.c +++ b/src/util/virnuma.c @@ -217,6 +217,56 @@ virNumaGetMaxNode(void)
/** + * virNumaGetDistances: + * @node: identifier of the requested NUMA node + * @distances: array of distances to sibling nodes + * @ndistances: size of @distances + * + * Get array of distances to sibling nodes from @node. If a + * distances[x] equals to zero, the node x is not enabled or + * doesn't exist. As a special case, if @node itself refers to + * disabled or nonexistent NUMA node, then @distances and + * @ndistances are set to NULL and zero respectively.
I think it'd be worth stating what the distance is between a node and itself, since that's another special case. I'd assumed that the distince between a ndoe and itself would be zero, but your next patch shows that it would be 10 which I find a bit bizarre. Presumably that's just what numactl, or perhaps the kernel, reports ? If we are relying on numactl's value ranges, then we should be clear about this to help people porting to non-Linux platforms. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|