Hi Paolo,Stefan,
At 12/05/2016 07:57 PM, Paolo Bonzini wrote:
On 05/12/2016 12:53, Stefan Hajnoczi wrote:
Adding the BlockBackend *query_blk parameter is a reasonable short-term
workaround. I wonder if the polling stats APIs need to be rethought in
the longer term.
Regarding the low-level details of block statistics inside QEMU, we can
probably collect statistics without requiring the AioContext lock. This
means guest I/O processing does not need to be interrupted. There
should be some RCU-style scheme that can be used to extract the stats.
The question is also what level of consistency you want. Perhaps as
long as you can access it atomically (so no tearing of values) you don't
need a lock at all, blk_ref/unref is enough.
Yes, that is what I want to express. When I use the command frequently,
I may want to sacrifice consistency, in exchange for performance.
Thanks,
Liyang.
