On Fri, Feb 9, 2024 at 9:58 AM Damien Le Moal <dlemoal@xxxxxxxxxx> wrote: > > On 2/9/24 09:28, Zhaoyang Huang wrote: > > 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. > > If properly designed, that patch would *not* be a block layer API/function and > so does not need review by block layer folks/Jens as it would simply set an IO > prio for a BIO issued by an FS. So that patch needs to be accepted by FS > people, for the FS you are interested in. Thanks for the heads-up, sorry for my none-sense on the needs of maintaining the whole framework. IMHO, the newly introduced API is a little bit like bio_set_pages_dirty which is mainly related to bio and the pages inside. Patchv9 has changed a lot to meet your kind advice. I would be grateful to you if you could review it. > > > -- > Damien Le Moal > Western Digital Research >
