[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAGWkznH6Y8u7PsoHWid0uQ+ceRK_qzSn6=eWn4dvDhK+DzSXzg@mail.gmail.com>
Date: Fri, 9 Feb 2024 08:02:27 +0800
From: Zhaoyang Huang <huangzhaoyang@...il.com>
To: Jens Axboe <axboe@...nel.dk>
Cc: "zhaoyang.huang" <zhaoyang.huang@...soc.com>, Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>, Juri Lelli <juri.lelli@...hat.com>,
Vincent Guittot <vincent.guittot@...aro.org>, Yu Zhao <yuzhao@...gle.com>,
linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
steve.kang@...soc.com
Subject: Re: [PATCH 3/3] block: introducing a bias over deadline's fifo_time
On Fri, Feb 9, 2024 at 1:49 AM Jens Axboe <axboe@...nel.dk> 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.
PS: [PATCHv9 1/1] block: introduce content activity based ioprio has
solved layering violation issue. Could you please have a look.
>
> --
> Jens Axboe
>
Powered by blists - more mailing lists