Re: [PATCH v2] blk-rq-qos: remove redundant finish_wait to rq_qos_wait.

From: Stephen Rothwell
Date: Tue Jul 14 2020 - 22:19:50 EST


Hi all,

On Tue, 14 Jul 2020 19:21:24 -0400 Qian Cai <cai@xxxxxx> wrote:
>
> On Sun, Jun 28, 2020 at 09:56:25AM -0400, Guo Xuenan wrote:
> > It is no need do finish_wait twice after acquiring inflight.
> >
> > Signed-off-by: Guo Xuenan <guoxuenan@xxxxxxxxxx>
> > ---
> > block/blk-rq-qos.c | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
> > index 656460636ad3..18f3eab9f768 100644
> > --- a/block/blk-rq-qos.c
> > +++ b/block/blk-rq-qos.c
> > @@ -273,8 +273,6 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data,
> > if (data.got_token)
> > break;
> > if (!has_sleeper && acquire_inflight_cb(rqw, private_data)) {
> > - finish_wait(&rqw->wait, &data.wq);
> > -
> > /*
> > * We raced with wbt_wake_function() getting a token,
> > * which means we now have two. Put our local token
> > --
> > 2.25.4
>
> Reverting this commit fixed an issue that swapping workloads will stall for
> days without being able to make any progress below.

I have reverted that commit from linux-next today.

--
Cheers,
Stephen Rothwell

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