[libvirt-users] VMs fail to start with NUMA configuration

Mon Jan 28 16:17:02 UTC 2013

On Sun, Jan 27, 2013 at 10:46 PM, Osier Yang <jyang at redhat.com> wrote:
> On 2013年01月28日 11:47, Osier Yang wrote:
>>
>> On 2013年01月28日 11:44, Osier Yang wrote:
>>>
>>> On 2013年01月26日 01:07, Doug Goldstein wrote:
>>>>
>>>> On Thu, Jan 24, 2013 at 12:58 AM, Osier Yang<jyang at redhat.com> wrote:
>>>>>
>>>>> On 2013年01月24日 14:26, Doug Goldstein wrote:
>>>>>>
>>>>>>
>>>>>> On Wed, Jan 23, 2013 at 11:02 PM, Osier Yang<jyang at redhat.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 2013年01月24日 12:11, Doug Goldstein wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Wed, Jan 23, 2013 at 3:45 PM, Doug Goldstein<cardoe at gentoo.org>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I am using libvirt 0.10.2.2 and qemu-kvm 1.2.2 (qemu-kvm 1.2.0 +
>>>>>>>>> qemu
>>>>>>>>> 1.2.2 applied on top plus a number of stability patches). Having
>>>>>>>>> issue
>>>>>>>>> where my VMs fail to start with the following message:
>>>>>>>>>
>>>>>>>>> kvm_init_vcpu failed: Cannot allocate memory
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Smell likes we have problem on setting the NUMA policy (perhaps
>>>>>>> caused by the incorrect host NUMA topology), given that the system
>>>>>>> still has enough memory. Or numad (if it's installed) is doing
>>>>>>> something wrong.
>>>>>>>
>>>>>>> Can you see if there is something about the Nodeset used to set
>>>>>>> the policy in debug log?
>>>>>>>
>>>>>>> E.g.
>>>>>>>
>>>>>>> % cat libvirtd.debug | grep Nodeset
>>>>>>
>>>>>>
>>>>>>
>>>>>> Well I don't see anything but its likely because I didn't do something
>>>>>> correct. I had LIBVIRT_DEBUG=1 exported and ran libvirtd --verbose
>>>>>> from the command line.
>>>>>
>>>>>
>>>>>
>>>>> If the process is in background, it's expected you can't see anything
>>>>>
>>>>>
>>>>> My /etc/libvirt/libvirtd.conf had:
>>>>>>
>>>>>>
>>>>>> log_outputs="3:syslog:libvirtd 1:file:/tmp/libvirtd.log" But I didn't
>>>>>> get any debug messages.
>>>>>
>>>>>
>>>>>
>>>>> log_level=1 has to be set.
>>>>>
>>>>> Anyway, let's simply do this:
>>>>>
>>>>> % service libvirtd stop
>>>>> % LIBVIRT_DEBUG=1 /usr/sbin/libvirtd 2>&1 | tee -a libvirtd.debug
>>>>>
>>>>
>>>> That's what I was doing, minus the tee just to the console and nothing
>>>> was coming out. Which is why I added the 1:file:/tmp/libvirtd.log,
>>>> which also didn't get any debug messages. Turns out this instance must
>>>> have been built with --disable-debug,
>>>>
>>>> All I've got in the log is:
>>>>
>>>> # grep -i 'numa' libvirtd.debug
>>>> 2013-01-25 16:50:15.287+0000: 417: debug : virCommandRunAsync:2200 :
>>>> About to run /usr/bin/numad -w 2:2048
>>>> 2013-01-25 16:50:17.295+0000: 417: debug : qemuProcessStart:3614 :
>>>> Nodeset returned from numad: 1
>>>
>>>
>>> This looks right.
>>>
>>>>
>>>> Immediately below that is
>>>>
>>>> 2013-01-25 16:50:17.295+0000: 417: debug : qemuProcessStart:3622 :
>>>> Setting up domain cgroup (if required)
>>>> 2013-01-25 16:50:17.295+0000: 417: debug : virCgroupNew:619 : New
>>>> group /libvirt/qemu/bb-2.6.35.9-i686
>>>> 2013-01-25 16:50:17.295+0000: 417: debug : virCgroupDetect:273 :
>>>> Detected mount/mapping 1:cpuacct at /sys/fs/cgroup/cpuacct in
>>>> 2013-01-25 16:50:17.295+0000: 417: debug : virCgroupDetect:273 :
>>>> Detected mount/mapping 2:cpuset at /sys/fs/cgroup/cpuset in
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupMakeGroup:537 :
>>>> Make group /libvirt/qemu/bb-2.6.35.9-i686
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupMakeGroup:562 :
>>>> Make controller /sys/fs/cgroup/cpuacct/libvirt/qemu/bb-2.6.35.9-i686/
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupMakeGroup:562 :
>>>> Make controller /sys/fs/cgroup/cpuset/libvirt/qemu/bb-2.6.35.9-i686/
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupCpuSetInherit:469
>>>> : Setting up inheritance /libvirt/qemu ->
>>>> /libvirt/qemu/bb-2.6.35.9-i686
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupGetValueStr:361 :
>>>> Get value /sys/fs/cgroup/cpuset/libvirt/qemu/cpuset.cpus
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virFileClose:72 : Closed
>>>> fd 39
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupCpuSetInherit:482
>>>> : Inherit cpuset.cpus = 0-63
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupSetValueStr:331 :
>>>> Set value
>>>> '/sys/fs/cgroup/cpuset/libvirt/qemu/bb-2.6.35.9-i686/cpuset.cpus'
>>>> to '0-63'
>>>
>>>
>>> This looks not right, it should be 0-7 instead.
>>>
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virFileClose:72 : Closed
>>>> fd 39
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupGetValueStr:361 :
>>>> Get value /sys/fs/cgroup/cpuset/libvirt/qemu/cpuset.mems
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virFileClose:72 : Closed
>>>> fd 39
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupCpuSetInherit:482
>>>> : Inherit cpuset.mems = 0-7
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupSetValueStr:331 :
>>>> Set value
>>>> '/sys/fs/cgroup/cpuset/libvirt/qemu/bb-2.6.35.9-i686/cpuset.mems'
>>>> to '0-7'
>>>
>>>
>>> This is right.
>>>
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virFileClose:72 : Closed
>>>> fd 39
>>>> 2013-01-25 16:50:17.296+0000: 417: warning : qemuSetupCgroup:388 :
>>>> Could not autoset a RSS limit for domain bb-2.6.35.9-i686
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virCgroupSetValueStr:331 :
>>>> Set value
>>>> '/sys/fs/cgroup/cpuset/libvirt/qemu/bb-2.6.35.9-i686/cpuset.mems'
>>>> to '1'
>>>
>>>
>>> And it's strange that the cpuset.mems is changed to '1' here.
>
>
> Oh, actually this is right, cpuset.mems is about the memory nodes.
>
>
>>>
>>>> 2013-01-25 16:50:17.296+0000: 417: debug : virFileClose:72 : Closed
>>>> fd 39
>>>>
>>>> Could the RSS issue be related? Some kernel related option not playing
>>>> nice or enabled?
>>
>>
>> Instead, I'm wondering if the problem is caused by the mismatch
>> (from libvirt p.o.v) between cpuset.cpus and cpuset.mems, which
>> thus cause the problem for kernel memory management?
>
>
> So, the simple method to prove the guess is to use static placement
> like:
>
> <vcpu placement='static' cpuset='0-63'>2</vcpu>
> <numatune>
>   <memory placement='static' nodeset='1'/>
> </numatune>
>
> Osier

Same error. Which I don't know if you expected or didn't expect.

-- 
Doug Goldstein