On 27 April 2016 at 10:38, Alberto Garcia <be...@igalia.com> wrote: > On Wed, Apr 27, 2016 at 09:29:02AM +0200, Pradeep Kiruvale wrote: > > > Thanks for the reply. I am still in the early phase, I will let you > > know if any changes are needed for the APIs. > > > > We might also have to implement throttle-group.c for 9p devices, if > > we want to apply throttle for group of devices. > > Fair enough, but again please note that: > > - throttle-group.c is not meant to be generic, but it's tied to > BlockDriverState / BlockBackend. > - it is currently being rewritten: > https://lists.gnu.org/archive/html/qemu-block/2016-04/msg00645.html > > If you can explain your use case with a bit more detail we can try to > see what can be done about it. > > We want to use virtio-9p for block io instead of virtio-blk-pci. But in case of virtio-9p we can just use fsdev devices, so we want to apply throttling (QoS) on these devices and as of now the io throttling only possible with the -drive option.
As a work around we are doing the throttling using cgroup. It has its own costs. So, we want to have throttling for fsdev devices inside the qemu itself. I am just trying to understand and estimate time required for implementing it for the fsdevices. -Pradeep