On Mon, Feb 20, 2017 at 04:45:54PM +0100, Kevin Wolf wrote: > > I can imagine two solutions that do not need these parameters in > > blockdev-add: > > > > 1. I/O throttling is implemented by a BlockDriver. Users are expected > > to create the BDS themselves. This is a little awkward since > > query-block *does* include the throttling parameters in its output > > and we must preserve this behavior for existing users. > > > > 2. block_set_io_throttle must be used after blockdev-add. Suboptimal > > because issuing two commands is not atomic (use transaction?). > > The existing I/O throttling code is working on BlockBackends, but > blockdev-add creates BlockDriverStates. So it can't possibly add > throttling parameters. > > The currently recommended solution block_set_io_throttle. The > other option to control BB level thorttling would be to add qdev > properties to the block devices. > > In the long term, I think going with 1. and moving throttling to the > block node level is the much nicer (and more flexible) option.
Yeah I agree with Kevin. Berto
