On 11/24/2010 09:16 AM, Paolo Bonzini wrote:
On 11/24/2010 12:14 PM, Michael S. Tsirkin wrote:
> buffered_file timer runs each 100ms. And we "try" to measure
channel
> bandwidth from there. If we are not able to run the timer, all the
> calculations are wrong, and then stalls happens.
So the problem is the timer in the buffered file abstraction?
Why don't we just flush out data if the buffer is full?
It takes a lot to fill the buffer if you have many zero pages, and if
that happens the guest is starved by the main loop filling the buffer.
Sounds like the sort of thing you'd only see if you created a guest a
large guest that was mostly unallocated and then tried to migrate. That
doesn't seem like a very real case to me though.
The best approach would be to drop qemu_mutex while processing this code
instead of having an arbitrary back-off point. The later is deferring
the problem to another day when it becomes the source of a future problem.
Regards,
Anthony Liguori
Paolo
