Hi, On 20 April 2017 at 15:03, kjaszczerski <kjaszczerski@xxxxxxxxx> wrote: > > I'm trying to run FIO on mmap engine on 4k socket and 4k channel. I'd like > to use wrokload with blocksize parameter value less than 4k, is it possible > ? You didn't give an example jobfile, fio version, operating system (which are really necessary to answer these types of questions) so the following is going to be a lot of speculation. I don't know if you also filed https://github.com/axboe/fio/issues/339 but there's a partial answer there (using direct=1 forces alignment and size constraints). There's a follow up point which is the message stems from a desire to catch msync related errors earlier: https://github.com/axboe/fio/commit/913ea0db12596b735a030a1836bd913497b7120a . I suppose a filesystem will never have a blocksize smaller than a page and alignment constraints mean an msync must always start page aligned (http://man7.org/linux/man-pages/man2/msync.2.html ) so if you have any type of fsync taking place that will trigger that check. -- Sitsofe | http://sucs.org/~sits/ -- 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
