Re: [Qemu-devel] [PATCH V7 0/5] Continuous Leaky Bucket Throttling

[Benoît Canet]

> 1. We keep modifying the timer in bdrv_io_limits_intercept() on each
>    request even when it has already been set.  I think we'll set it to
>    the same absolute timestamp, modulo numerical issues.  Should we
>    avoid doing this?

I could check that the timer is not pending before setting it.

> 
> 2. bdrv_io_limits_resched() only wakes up requests of the same type
>    (read/write).  Does this mean that BPS_TOTAL/IOPS_TOTAL requests
>    will have to wait until the other request type timer expires instead
>    of piggybacking on request completion?
> 
>    Is this a problem?  If no, then why piggyback on request completion
>    at all since apparently it works fine when we don't wake up the other
>    request type?

It only wakes up the same request type to be coherent with the two requests
queues and two timers strategy.
The ultimate goal of this is to be able to do:
block_set_io_throttle virtio1 0 0 0 0 3000 1
The code can cope with this and do independent throttling for reads and
writes.

Best regards

Benoît