On Thu, Jun 27 2013, Carl Zwanzig wrote: > > From: Jens Axboe [mailto:axboe@xxxxxxxxx] > > Sent: Thursday, June 27, 2013 2:01 AM > > > See percentage_random in the man page (or --cmdhelp=percentage_random) > > In the tests I'm running, the sequence has to continue essentially > uninterrupted with the occasional drop/transposition, but it can't > contain LBAs that are wildly off. So '1 2 3 (4) 5 6' or '1 2 3 (5 4) > 6' are good, '1 2 3 9999 4 5 6' is not. They trigger different > specific behaviors in some hard drives. > > Is there a good place in the code to insert this sort or thing? I would look at the profile support in fio. That allows you to hook into io_u.c:get_next_offset(), which is where fio decides what the next offset should be. If a profile defines ops->fill_io_u(), then that is called instead. That gives you absolute control of the IO pattern, without having to modify core fio code. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
