> On Oct 22, 2014, at 6:43 AM, Michal Skrivanek <[email protected]> > wrote: > > On Oct 21, 2014, at 18:13 , Darrell Budic <[email protected]> wrote: > >> Was poking at this a little to see if there was any tuning that could affect >> it and spotted some oddness with the processor counts on my VMs under Ovirt >> 3.4. They seem to think they only have the proper number I set in ovirt (as >> shown in /proc/cpu), but if I look at dmidecode, there’s 159 bogus >> processors listed. I’d expect maybe 16 from the -smp >> 1,maxcpus=16,sockets=16,cores=1,threads=1 argument to qemu-kvm, but there >> are 0xa0 of them. Maybe this is a seabios or qemu-kvm issue causing all >> those extras? Anyway, the # of rcu* processes matches pretty well, so that’s >> likely where it’s coming from. >> >> At least they shouldn’t be causing a performance issue, given their purpose >> as non-blocking work threads, but it is odd to see. >> >> Punit, did you open a BZ I can add these details to? >> >> BTW, this appears to be corrected with some component of Ovirt 3.5 (probably >> qemu-rhev?). On VMs started after I upgraded my Engine (even on 3.4 vdsmds), >> I’m only seeing 16 “processors” in the bios, and thus only 16 of the various >> rcu* processes. Could have been a general Centos 6.5 update too, since I did >> those as well, so I can’t get any finer resolution on that issue (both >> engine and host nodes, lots of Centos 7 VMs). >> >> If there is a RFE for this, perhaps a configurable max # of CPU sockets for >> hot add could be added, or it could be limited to the max physical cpu count >> of the biggest host in the cluster? > > The max is 16. Roy, what can we change/not change after your latest changes? > I suppose it's related to teh maximum values we send because of hotplug > support > > Thanks, > michal
Yes, definitely looks like a side effect of hot plug. The 160 rcu issues look like a bug somewhere else, 16 is more normal for the default. I had missed the engine setting for MaxNumOfVmCpus, I’ll probably set that for my smaller hosts just to keep it reasonable for the hardware it’s on. > From: "Punit Dambiwal" <[email protected]> > To: "Doron Fediuck" <[email protected]> > Sent: Wednesday, October 22, 2014 4:19:56 AM > Subject: Re: [ovirt-users] Guest VM Running 160 RCU Processes > > Hi Darrell, > > I haven't open a BZ for the same...please let me know how i can open BZ ?? Punit, make sure your replies go to the list, this didn’t get to me. But you want to go to http://www.ovirt.org/Community and look at the “Find and File Bugs” section to raise a bug or file an RFE. -Darrell _______________________________________________ Users mailing list [email protected] http://lists.ovirt.org/mailman/listinfo/users
