[Qemu-devel] [Bug 648356] [NEW] VirtFS possible memory leak in 9p virtio mapped

[Moshroum]

Public bug reported:

I use as client Debian squeeze i386 with a custom kernel:
Linux (none) 2.6.35.5 #3 Thu Sep 23 18:36:02 UTC 2010 i686 GNU/Linux

And as host Debian squeeze amd64
Linux asd 2.6.32-5-amd64 #1 SMP Fri Sep 17 21:50:19 UTC 2010 x86_64 GNU/Linux

kvm version is:
kvm-88-5908-gdd67374

Started the client using:
sudo /usr/local/kvm/bin/qemu-system-x86_64 -m 1024 -kernel linux-2.6.35.5.qemu 
-drive file=root.img,if=virtio -net 
nic,macaddr=02:ca:ff:ee:ba:be,model=virtio,vlan=1 -net 
tap,ifname=tap1,vlan=1,script=no -virtfs 
local,path=/host,security_model=mapped,mount_tag=host -nographic


I've done following inside the guest:

$  mount -t 9p -o trans=virtio host /mnt
$ rm -f /mnt/test
$ touch /mnt/test
$ ls -l /mnt/test
$ while true ;do ls -l /host/test > /dev/null; done

Now I can see on my host system that the memory consumption starts at
90MB and after a minute it raises to 130MB.  The extra memory
consumption stops when I stop the while-loop.

$ while true ;do ls -l /tmp > /dev/null; done

Doesn't show that behaviour.

** Affects: qemu
     Importance: Undecided
         Status: New

-- 
VirtFS possible memory leak in 9p virtio mapped
https://bugs.launchpad.net/bugs/648356
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Status in QEMU: New

Bug description:
I use as client Debian squeeze i386 with a custom kernel:
Linux (none) 2.6.35.5 #3 Thu Sep 23 18:36:02 UTC 2010 i686 GNU/Linux

And as host Debian squeeze amd64
Linux asd 2.6.32-5-amd64 #1 SMP Fri Sep 17 21:50:19 UTC 2010 x86_64 GNU/Linux

kvm version is:
kvm-88-5908-gdd67374

Started the client using:
sudo /usr/local/kvm/bin/qemu-system-x86_64 -m 1024 -kernel linux-2.6.35.5.qemu 
-drive file=root.img,if=virtio -net 
nic,macaddr=02:ca:ff:ee:ba:be,model=virtio,vlan=1 -net 
tap,ifname=tap1,vlan=1,script=no -virtfs 
local,path=/host,security_model=mapped,mount_tag=host -nographic


I've done following inside the guest:

$  mount -t 9p -o trans=virtio host /mnt
$ rm -f /mnt/test
$ touch /mnt/test
$ ls -l /mnt/test
$ while true ;do ls -l /host/test > /dev/null; done

Now I can see on my host system that the memory consumption starts at 90MB and 
after a minute it raises to 130MB.  The extra memory consumption stops when I 
stop the while-loop.

$ while true ;do ls -l /tmp > /dev/null; done

Doesn't show that behaviour.