* Daniel P. Berrange <berrange@xxxxxxxxxx> [2007-09-28 13:54]: > On Fri, Sep 28, 2007 at 01:08:08PM -0500, Ryan Harper wrote: > > * Daniel Veillard <veillard@xxxxxxxxxx> [2007-09-28 12:59]: > > > On Fri, Sep 28, 2007 at 12:41:21PM -0500, Ryan Harper wrote: > > > > * Elizabeth Kon <eak@xxxxxxxxxx> [2007-09-28 12:32]: > > > > > >no, we can always get a total of _free_ memory, we just don't have a > > > > > >call for _total_ ram (ie, free and non-free) -- only what's in the heap > > > > > >(free mem). > > > > > > > > > > > > > > > > > > > > > > > I asked DV about this off-list and he said he actually wanted total, not > > > > > free. DV please correct me if I misunderstood. > > > > > > > > Ah, OK - the text as written mentions _free_ - which is why I responded. > > > > > > It seems a bit silly to me to have topology informations about which > > > CPUs are part of the same Cell (i.e. share the same memory costs) but > > > being unable to find out how much memory is actually local to that cell. > > > Sure the current free heap on that cell helps to place new jobs but it's > > > only a temporary view. > > > > I don't see how having the total changes anything - we need current free > > to determine where the next (even first) vm should go. > > While its not technically neccessary, it will help with an UI visualization > of the host's allocation state, which IMHO is pretty important because we > need good visualization to help users understand this stuff. Fair enough. Currently xen doesn't give us this information directly -- the raw SRAT table parsing includes physical addr ranges that could be used to calculate the total size of a numa-node. I might have an old patch that exported the physical ranges for each node as part of the physinfo hcall -- that wasn't accepted by the Xen folks at the time. > > BTW, does the Xen model allow for fact that you can have NUMA cells which > only have memory - ie no CPUs attached. This is something that's possible > in ia64 boxes... AFAIK, yes. The Xen NUMA parsing and data structures are based upon Linux NUMA which as I understand it handles the above case. > > Dan. > -- > |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| > |=- Perl modules: http://search.cpan.org/~danberr/ -=| > |=- Projects: http://freshmeat.net/~danielpb/ -=| > |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@xxxxxxxxxx -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list