Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220128173006.1713210-1-geert@linux-m68k.org>
 <63c80eba-7c55-2a92-8078-c63cec3c9efb@gmail.com> <8913a0a2-9496-143c-18c2-f3023fd37ba0@gmail.com>
 <8d215dab-cd0f-452b-281b-f67c9324b53b@gmail.com>
In-Reply-To: <8d215dab-cd0f-452b-281b-f67c9324b53b@gmail.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Sat, 5 Feb 2022 09:31:52 +0100
Message-ID: <CAMuHMdVnkvSCHKt5ouZP7HrMBg7nPg7fjiio-KVJ7dehA=FwyQ@mail.gmail.com>
Subject: Re: Regression in 5.17-rc1 on pata-falcon (was: Re: [PATCH] m68k: mm:
 Remove check for VM_IO to fix deferred I/O)
To:     Michael Schmitz <schmitzmic@gmail.com>
Cc:     linux-m68k <linux-m68k@lists.linux-m68k.org>,
        Jens Axboe <axboe@kernel.dk>,
        Laibin Qiu <qiulaibin@huawei.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-block <linux-block@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Michael,

On Sat, Feb 5, 2022 at 1:04 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> commit 180dccb0dba4f5e84a4a70c1be1d34cbb6528b32 (blk-mq: fix tag_get
> wait task can't be awakened) does cause a regression on my m68k hardware
> test rig (m68k Falcon030, IDE disk attached through pata-falcon driver
> which does use polled IO instead of interrupts, so may be a little on
> the slow side).

> Bisection between v5.16 and v5.17-rc1 points to
> 180dccb0dba4f5e84a4a70c1be1d34cbb6528b32 as the culprit, which is
> corroborated by reverting that commit in v5.17-rc1 and booting as
> rapidly as before.

Now you know the culprit, it looks like several other people ran into this.
Does this fix help?
https://lore.kernel.org/all/1643040870.3bwvk3sis4.none@localhost/

It is commit 10825410b956dc1e ("blk-mq: Fix wrong wakeup
batch configuration which will cause hang") in v5.17-rc2.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds