Re: [Qemu-devel] Qemu start VM in huge page without '-mem-prealloc' will get memory leak?

[Sam]

I don't know if this process is:
1. qemu call kernel API to alloc 40G memory.
2. qemu process is killed by hand.
3. kernel alloc 40G memory, but qemu process is down, then this 40G is left
in kernel.

2017-10-26 11:54 GMT+08:00 Sam <address@hidden>:

> BTW, I start VM by this command, and then stop it, then memory leak
> happens.
>
> To compare, I start another VM, and wait for about 10 minutes, and then
> kill it as I does above, then no memory leak happens.
>
> So is this a bug of KVM or qemu ?
>
> 2017-10-26 11:09 GMT+08:00 Sam <address@hidden>:
>
>> For qemu-2.6.0, in huge page (1G) environment, after kill the qemu
>> process, memory which is alloc for the vm could not be released. Detail is
>> bellow.
>> Or should I use some specific command to stop vm? I want to know if there
>> someone has the same problem?
>>
>> The start up command is:
>>
>> CMD1="$QEMU_CMD -D qemu.log -trace events=qemu-events-all -enable-kvm
>> -cpu qemu64,+vmx,+ssse3,+sse4.1,+sse4.2,+x2apic,+aes,+avx,+vme,+p
>> at,+ss,+pclmulqdq,+xsave,level=13 -machine pc,accel=kvm -chardev
>> socket,id=hmqmondev,port=55908,host=127.0.0.1,nodelay,server,nowait -mon
>> chardev=hmqmondev,id=hmqmon,mode=readline -rtc
>> base=utc,clock=host,driftfix=none -usb -device usb-tablet -daemonize
>> -nodefaults -nodefconfig -no-kvm-pit-reinjection -global
>> kvm-pit.lost_tick_policy=discard -vga std -k en-us -smp 8 -name
>> gangyewei-qemutime-1 -m 40960 -boot order=cdn -vnc :8,password -drive
>> file=$DISK_0,if=none,id=drive_0,format=qcow2,cache=none,aio=native
>> -device virtio-blk-pci,id=dev_drive_0,drive=drive_0,bus=pci.0,addr=0x5
>> -drive file=$DISK_1,if=none,id=drive_1,format=qcow2,cache=none,aio=native
>> -device virtio-blk-pci,id=dev_drive_1,drive=drive_1,bus=pci.0,addr=0x6
>> -drive file=$DISK_2,if=none,id=drive_2,format=qcow2,cache=none,aio=native
>> -device virtio-blk-pci,id=dev_drive_2,drive=drive_2,bus=pci.0,addr=0x7
>> -device ide-cd,drive=ide0-cd0,bus=ide.1,unit=1 -drive
>> id=ide0-cd0,media=cdrom,if=none -chardev socket,id=char-n-52b49b80,path
>> =/usr/local/var/run/openvswitch/n-52b49b80,server -netdev
>> type=vhost-user,id=n-52b49b80,chardev=char-n-52b49b80,vhostforce=on
>> -device virtio-net-pci,netdev=n-52b49b80,mac=00:22:52:b4:9b:80,id=ne
>> tdev-n-52b49b80,addr=0xf$(nic_speed 10000) -object
>> memory-backend-file,id=mem,size=40960M,mem-path=/mnt/huge,share=on -numa
>> node,memdev=mem -pidfile $PID_FILE -chardev socket,path=/opt/cloud/
>> workspace/servers/4511f52a-f450-40d3-9417-a1e0a27ed507/qga.sock,server,nowait,id=qga0
>> -device virtio-serial -device virtserialport,chardev=qga0,na
>> me=org.qemu.guest_agent.0"
>>
>> The stop script is just kill this process.
>>
>> the result of `cat /proc/meminfo` show memory is still there.
>>
>
>