Am 03.04.2011 10:31, schrieb Avishay Traeger: > > Revised patch for improving the accuracy of the block migration bandwidth > calculation. Thanks a lot to Michael Roth for the input. > > For those that missed the original patch, here is the description: > block_mig_state.total_time is currently the sum of the read request > latencies. This is not very accurate because block migration uses aio and > so several requests can be submitted at once. Bandwidth should be computed > with wall-clock time, not by adding the latencies. In this case, > "total_time" has a higher value than it should, and so the computed > bandwidth is lower than it is in reality. This means that migration can > take longer than it needs to. > However, we don't want to use pure wall-clock time here. We are computing > bandwidth in the asynchronous phase, where the migration repeatedly wakes > up and sends some aio requests. The computed bandwidth will be used for > synchronous transfer. > > > Avishay > > > Signed-off-by: Avishay Traeger <avis...@il.ibm.com>
Thanks. Fixed line wraps and coding style and applied to the block branch. Please take care to avoid patch corruption next time - usually such patches are not fixed manually, but rejected. Kevin
