On 10/3/22 3:43 AM, Sagi Grimberg wrote: > Our mpath stack device is just a shim that selects a bottom namespace > and submits the bio to it without any fancy splitting. This also means > that we don't clone the bio or have any context to the bio beyond > submission. However it really sucks that we don't see the mpath device > io stats. > > Given that the mpath device can't do that without adding some context > to it, we let the bottom device do it on its behalf (somewhat similar > to the approach taken in nvme_trace_bio_complete). > > When the IO starts, we account the request for multipath IO stats using > REQ_NVME_MPATH_IO_STATS nvme_request flag to avoid queue io stats disable > in the middle of the request. Reviewed-by: Jens Axboe <axboe@xxxxxxxxx> -- Jens Axboe
