On 3 April 2018 at 15:21, Jens Axboe <axboe@xxxxxxxxx> wrote: > On 4/3/18 6:08 AM, Sitsofe Wheeler wrote: >> >> Is there any particular reason the new(ish) BFQ and Kyber I/O >> schedulers have not been added to the "Default I/O scheduler" choices >> in block/Kconfig.iosched ? Is it because they are multiqueue only? > > Yes, the default scheduler selection only applies to !mq schedulers. > If you search the git log for "Architected-by" you can see why, > there's some mailing archive goodness on the topic from the same > time, too. For those playing along at home the commit Jens is referring to is "block: get rid of blk-mq default scheduler choice Kconfig entries" (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b86dd815ff74ab9eda474d1c28428ac0db2c3032 ) and the mailing archive thread was https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1338302.html ). Sigh, OK got it - udev rules for selecting multiqueue I/O schedulers (at least until the day single queue block layer is ripped out). (Finishing that thread made me feel like I'd been slapped in the face by a wet trout and I had nothing to do with it! :-) -- Sitsofe | http://sucs.org/~sits/
