Re: Regression in 5.17-rc1 on pata-falcon (was: Re: [PATCH] m68k: mm: Remove check for VM_IO to fix deferred I/O)

Geert Uytterhoeven
2022-02-05T08:32:06Z

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