On Fri, Feb 9, 2024 at 8:11 AM Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 2/8/24 5:02 PM, Zhaoyang Huang wrote: > > On Fri, Feb 9, 2024 at 1:49?AM Jens Axboe <axboe@xxxxxxxxx> wrote: > >> > >> On 2/8/24 2:31 AM, zhaoyang.huang wrote: > >>> diff --git a/block/mq-deadline.c b/block/mq-deadline.c > >>> index f958e79277b8..43c08c3d6f18 100644 > >>> --- a/block/mq-deadline.c > >>> +++ b/block/mq-deadline.c > >>> @@ -15,6 +15,7 @@ > >>> #include <linux/compiler.h> > >>> #include <linux/rbtree.h> > >>> #include <linux/sbitmap.h> > >>> +#include "../kernel/sched/sched.h" > >>> > >>> #include <trace/events/block.h> > >>> > >>> @@ -802,6 +803,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, > >>> u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio); > >>> struct dd_per_prio *per_prio; > >>> enum dd_prio prio; > >>> + int fifo_expire; > >>> > >>> lockdep_assert_held(&dd->lock); > >>> > >>> @@ -840,7 +842,9 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, > >>> /* > >>> * set expire time and add to fifo list > >>> */ > >>> - rq->fifo_time = jiffies + dd->fifo_expire[data_dir]; > >>> + fifo_expire = task_is_realtime(current) ? dd->fifo_expire[data_dir] : > >>> + CFS_PROPORTION(current, dd->fifo_expire[data_dir]); > >>> + rq->fifo_time = jiffies + fifo_expire; > >>> insert_before = &per_prio->fifo_list[data_dir]; > >>> #ifdef CONFIG_BLK_DEV_ZONED > >>> /* > >> > >> Hard pass on this blatant layering violation. Just like the priority > >> changes, this utterly fails to understand how things are properly > >> designed. > > IMHO, I don't think this is a layering violation. bio_set_ioprio is > > the one which introduces the scheduler thing into the block layer, > > this commit just wants to do a little improvement based on that. This > > commit helps CFS task save some IO time when preempted by RT heavily. > > Listen, both this and the previous content ioprio thing show a glaring > misunderstanding of how to design these kinds of things. You have no > grasp of what the different layers do, or how they interact. I'm not > sure how to put this kindly, but it's really an awful idea to hardcore > some CFS helper into the IO scheduler. The fact that you had to fiddle > around with headers to make it work was the first warning sign, and the > fact that you didn't stop at that point to consider how it could be > properly done makes it even worse. > > You need to stop sending kernel patches until you understand basic > software design. Neither of these patches are going anywhere until this > happens. There's been plenty of feedback to telling you that, but you > seem to just ignore it and plow on ahead. Stop. Ok, thanks for pointing this out, I will follow your advice. But I have to say that '[PATCHv9 1/1] block: introduce content activity based ioprio' really solved layering violation things. I would like to humbly ask for your kindly patient to have a look, as it is really helpful. > > -- > Jens Axboe >
