Hello Minchan, On (10/07/16 15:33), Minchan Kim wrote: [..] > > as soon as wb flush kworker can't keep up anymore things are going off > > the rails. most of the time, fio-template-static-buffer are in D state, > > while the biggest bdi flush kworker is doing the job (a lot of job): > > > > PID USER PR NI VIRT RES %CPU %MEM TIME+ S COMMAND > > 6274 root 20 0 0.0m 0.0m 100.0 0.0 1:15.60 R [kworker/u8:1] > > 11169 root 20 0 718.1m 1.6m 16.6 0.0 0:01.88 D fio ././conf/fio-template-static-buffer > > 11171 root 20 0 718.1m 1.6m 3.3 0.0 0:01.15 D fio ././conf/fio-template-static-buffer > > 11170 root 20 0 718.1m 3.3m 2.6 0.1 0:00.98 D fio ././conf/fio-template-static-buffer > > > > > > and still working... > > > > 6274 root 20 0 0.0m 0.0m 100.0 0.0 3:05.49 R [kworker/u8:1] > > 12048 root 20 0 718.1m 1.6m 16.7 0.0 0:01.80 R fio ././conf/fio-template-static-buffer > > 12047 root 20 0 718.1m 1.6m 3.3 0.0 0:01.12 D fio ././conf/fio-template-static-buffer > > 12049 root 20 0 718.1m 1.6m 3.3 0.0 0:01.12 D fio ././conf/fio-template-static-buffer > > 12050 root 20 0 718.1m 1.6m 2.0 0.0 0:00.98 D fio ././conf/fio-template-static-buffer > > > > and working... [..] > Isn't it blk-mq you mentioned? With blk-mq, I have some concerns. > > 1. read speed degradation > 2. no work with rw_page > 3. more memory footprint by bio/request queue allocation yes, I did. and I've seen your concerns in another email - I just don't have enough knowledge at the moment to say something not entirely stupid. gotta look more at the whole thing. > Having said, it's worth to look into it in detail more. > I will have time to see that approach to know what I can do > with that. thanks a lot! will keep looking as well. -ss -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
