Re: [Qemu-devel] [PATCH 4/4] block: add bdrv_co_discard and bdrv_aio_discard support

[Paolo Bonzini]

On 10/14/2011 04:32 PM, Kevin Wolf wrote:
> >  I can certainly drop aio_discard from the backends, but I'm not sure how
> >  heavy can fallocate be (with FALLOC_FL_PUNCH_HOLE).  Probably not much,
> >  but I think there's no guarantee of O(1) behavior especially with
> >  filesystems like ecryptfs.  So you would need to go through the thread
> >  pool and aio_discard would come in handy.
>
> Sure, but the coroutine interface should be just as good for
> implementing it this way in raw-posix.

I think until someone rewrites raw_aio_submit/paio_submit in terms of 
coroutines, it's better to keep aio_discard.

Paolo