Re: Memory usage with qemu-kvm-0.12.1.1

[Avi Kivity <avi@redhat.com>]

On 01/04/2010 05:12 PM, Thomas Fjellstrom wrote:
> On Sun January 3 2010, Thomas Fjellstrom wrote:
>    
>> On Sun December 27 2009, Avi Kivity wrote:
>>      
>>> On 12/27/2009 07:00 PM, Daniel Bareiro wrote:
>>>        
>>>>> Also, qemu might be leaking memory.  Please post 'pmap $pid' for all
>>>>> of your guests (do that before any of the other tests, on your
>>>>> swapped-out system).
>>>>>            
>>>> ---------------------------------------------------------------------
>>>>
>>>>    total           626376K
>>>>
>>>>    total           626472K
>>>>
>>>>    total           626396K
>>>>
>>>>    total           635292K
>>>>
>>>>    total           625388K
>>>>          
>>> These all seem sane.  So it's a swap regression, hopefully
>>> 2.6.32.something will have a fix.
>>>        
>> Sorry to butt in, but heres something I've found odd:
>>
>> # ps aux | grep /usr/bin/kvm | grep -v grep | cut -f6 -d' ' | xargs -n 1
>>   -i{} pmap {} | grep total total           845928K
>>   total           450336K
>>   total           441968K
>>   total           440740K
>>   total           845848K
>>   total           465808K
>>
>> root     10466  2.6  6.2 845924 253804 ?       Sl    2009 2084:29
>>   /usr/bin/kvm -S -M pc -m 512 -smp 1 -name awiki -uuid
>>   330abdce-f657-e0e2-196b-5bf22c0e76f0 -monitor
>>   unix:/var/lib/libvirt/qemu/awiki.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/awiki-root,if=virtio,index=0,boot=on -drive
>>   file=/dev/vg0/awiki-swap,if=virtio,index=1 -drive
>>   file=/mnt/boris/data/pub/diskimage/debian-503-amd64-netinst.iso,if=ide,m
>> edia=cdrom,index=2,format= -net
>>   nic,macaddr=52:54:00:35:8b:fb,vlan=0,model=virtio,name=virtio.0 -net
>>   tap,fd=19,vlan=0,name=tap.0 -serial pty -parallel none -usb -vnc
>>   127.0.0.1:2 -k en-us -vga vmware root     13953  0.2  1.3 450332 54832 ?
>>          Sl    2009 167:25 /usr/bin/kvm -S -M pc -m 128 -smp 1 -name nginx
>>   -uuid 793160c1-5800-72cf-7b66-8484f931d396 -monitor
>>   unix:/var/lib/libvirt/qemu/nginx.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/nginx,if=virtio,index=0,boot=on -net
>>   nic,macaddr=52:54:00:06:49:d5,vlan=0,model=virtio,name=virtio.0 -net
>>   tap,fd=21,vlan=0,name=tap.0 -serial pty -parallel none -usb -vnc
>>   127.0.0.1:3 -k en-us -vga vmware root     14051 31.4  6.7 441964 273132
>>   ?       Rl   01:19  30:35 /usr/bin/kvm -S -M pc -m 256 -smp 1 -name
>>   pfsense -uuid 0af4dfac-70f1-c348-9ce5-0df18e9bdc2c -monitor
>>   unix:/var/lib/libvirt/qemu/pfsense.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/pfsense,if=ide,index=0,boot=on -net
>>   nic,macaddr=00:19:5b:86:3e:fb,vlan=0,model=e1000,name=e1000.0 -net
>>   tap,fd=22,vlan=0,name=tap.0 -net
>>   nic,macaddr=52:54:00:53:62:b9,vlan=1,model=e1000,name=e1000.1 -net
>>   tap,fd=28,vlan=1,name=tap.1 -serial pty -parallel none -usb -vnc
>>   0.0.0.0:0 -k en-us -vga vmware root     15528 19.7  6.6 440736 270484 ?
>>        Sl   01:37  15:38 /usr/bin/kvm -S -M pc -m 256 -smp 1 -name
>>   pfsense2 -uuid 2c4000a0-7565-b12d-1e2a-1e77cdb778d3 -monitor
>>   unix:/var/lib/libvirt/qemu/pfsense2.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/pfsense2,if=ide,index=0,boot=on -drive
>>   file=/mnt/boris/data/pub/diskimage/pfSense-1.2.2-LiveCD-Installer.iso,if
>> =ide,media=cdrom,index=2,format= -net
>>   nic,macaddr=52:54:00:38:fc:a7,vlan=0,model=e1000,name=e1000.0 -net
>>   tap,fd=28,vlan=0,name=tap.0 -net
>>   nic,macaddr=00:24:1d:18:f8:f6,vlan=1,model=e1000,name=e1000.1 -net
>>   tap,fd=29,vlan=1,name=tap.1 -serial pty -parallel none -usb -vnc
>>   127.0.0.1:1 -k en-us -vga vmware root     27079  0.9  0.7 845700 30768 ?
>>          SLl   2009 584:28 /usr/bin/kvm -S -M pc -m 512 -smp 1 -name
>>   asterisk -uuid a87d8fc1-ea90-0db4-d6fe-c04e8f2175e7 -monitor
>>   unix:/var/lib/libvirt/qemu/asterisk.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/asterisk,if=virtio,index=0,boot=on -net
>>   nic,macaddr=52:54:00:68:db:fc,vlan=0,model=virtio,name=virtio.0 -net
>>   tap,fd=23,vlan=0,name=tap.0 -serial pty -parallel none -usb -vnc
>>   127.0.0.1:5 -k en-us -vga vmware -soundhw es1370 root     31214  0.6
>>   2.9 465804 121476 ?       Sl    2009 207:08 /usr/bin/kvm -S -M pc -m 256
>>   -smp 1 -name svn -uuid 6e30e0be-1781-7a68-fa5d-d3c69787e705 -monitor
>>   unix:/var/lib/libvirt/qemu/svn.monitor,server,nowait -boot c -drive
>>   file=/dev/vg0/svn-root,if=virtio,index=0,boot=on -net
>>   nic,macaddr=52:54:00:7d:f4:0b,vlan=0,model=virtio,name=virtio.0 -net
>>   tap,fd=27,vlan=0,name=tap.0 -serial pty -parallel none -usb -vnc
>>   0.0.0.0:4 -k en-us -vga vmware
>>
>> several of these vms are actually assigned less memory than is stated in
>>   -m, since I used the virt-manager interface to shrink memory size. awiki
>>   is set to 256MB, yet is still somehow using over 800MB of virt? one of
>>   the "anon" maps in pmap shows up as nearly 512MB (544788K). The rest of
>>   the vms show oddities like that as well.
>>
>> host is debian sid with the 2.6.31-2-amd64 kernel, kvm --version reports:
>>
>> QEMU PC emulator version 0.10.50 (qemu-kvm-devel-88)
>>
>> and just for kicks:
>>
>> root@boris:~# free -m
>>               total       used       free     shared    buffers     cached
>> Mem:          3964       3891         72          0        108       1686
>> -/+ buffers/cache:       2096       1867
>> Swap:         7627        383       7244
>>
>>      
> Would this be normal for my setup? The virt usage seems abnormally high for
> all of my guests, especially the ones using over 800MB virt.
>    

That's expected due to how glibc manages the heap.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.