(urgh, apologies for the html)
We use io_start_time_ns in dm-mpath.c, but the only actual user is
historical-service-time currently. We need
blk_stat_enable_accounting()/blk_stat_disable_accounting() calls
somewhere.
I was considering adding a new multipath feature flag, but we already
have "DM_PS_USE_HR_TIMER", which seems similar in spirit. Would that
re-use make sense?
Khazhy