Messages in this thread | | | Date | Wed, 4 Nov 2009 15:08:28 +0200 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCHv7 3/3] vhost_net: a kernel-level virtio server |
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On Wed, Nov 04, 2009 at 01:59:57PM +0100, Andi Kleen wrote: > > Fine? > > I cannot say -- are there paths that could drop the device beforehand?
Do you mean drop the mm reference?
> (as in do you hold a reference to it?)
By design I think I always have a reference to mm before I use it.
This works like this: ioctl SET_OWNER - calls get_task_mm, I think this gets a reference to mm ioctl SET_BACKEND - checks that SET_OWNER was run, starts virtqueue ioctl RESET_OWNER - stops virtqueues, drops the reference to mm file close - stops virtqueues, if we still have it then drops mm
This is why I think I can call use_mm/unuse_mm while virtqueue is running, safely. Makes sense?
> -Andi > -- > ak@linux.intel.com -- Speaking for myself only.
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