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 > > -Darrell > >> On Oct 20, 2014, at 7:34 AM, Doron Fediuck <[email protected]> wrote: >> >> >> >> ----- Original Message ----- >>> From: "Punit Dambiwal" <[email protected]> >>> To: [email protected], "Dan Kenigsberg" <[email protected]>, "Itamar Heim" >>> <[email protected]>, [email protected] >>> Sent: Monday, October 20, 2014 5:58:20 AM >>> Subject: Re: [ovirt-users] Guest VM Running 160 RCU Processes >>> >>> Hi, >>> >>> Is there any body suggest me good way to handle it....?? >>> >>> On Fri, Oct 17, 2014 at 3:15 PM, Punit Dambiwal < [email protected] > wrote: >>> >>> >>> >>> Hi, >>> >>> I have one Ovirt cluster and under this cluster all the guest machines (such >>> as centos,ubuntu,debian etc) almost 160 RCU processes running.... >>> >>> i searched on google about the RCU (It's kernel process "read-copy-upate") >>> >>> http://lwn.net/Articles/518953/ >>> >>> I want to know how i can modify this 160 processes to 10-20 or how i can to >>> disable it....is there any bed impact if i disable it.... >>> >>> Thanks, >>> Punit >>> >>> >> >> Hi Punit, >> we need to do a bit of a research on this one. >> In order to make sure we keep track of it, do you mind opening an RFE (BZ) >> with all the relevant details, including the hardware that you're using, >> guests config, how busy the guests/host are, Which hypervisor is used and >> the versions. >> >> Thanks, >> Doron >> _______________________________________________ >> Users mailing list >> [email protected] >> http://lists.ovirt.org/mailman/listinfo/users > > _______________________________________________ > Users mailing list > [email protected] > http://lists.ovirt.org/mailman/listinfo/users _______________________________________________ Users mailing list [email protected] http://lists.ovirt.org/mailman/listinfo/users
