[Qemu-devel] is there a limit on the number of in-flight I/O operations?

[Chris Friesen]

Hi,

I've recently run up against an interesting issue where I had a number 
of guests running and when I started doing heavy disk I/O on a virtio 
disk (backed via ceph rbd) the memory consumption spiked and triggered 
the OOM-killer.

I want to reserve some memory for I/O, but I don't know how much it can 
use in the worst-case.

Is there a limit on the number of in-flight I/O operations?  (Preferably 
as a configurable option, but even hard-coded would be good to know as 
well.)

Thanks,
Chris