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

On 03/12/2010 06:32 AM, Daniel Veillard wrote: > On Thu, Mar 11, 2010 at 06:00:56PM -0500, Chris Lalancette 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. > > okay > >> 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. > > well it makes little sense to refresh all the time, > I would expect some kind of signal we can hook on to detect > change in topology or capacities, though I don't see anything > on signal.h for this Well, it's actually not horrible to refresh all of the time. The way we get this information is all in memory (from /proc or /sys), so it's a very fast operation. That being said, if we can get a signal when things change, and just react to that, that's probably the best way to go. This stuff is all very new, so things are still being put into place; we'll just have to figure out how to be more dynamic in the future.