Re: Patch "dm delay: for short delays, use kthread instead of timers and wq" has been added to the 6.6-stable tree

[Sasha Levin <sashal@kernel.org>]

On Wed, Nov 29, 2023 at 08:02:23PM +0100, Mikulas Patocka wrote:
>
>
>On Wed, 29 Nov 2023, Sasha Levin wrote:
>
>> On Wed, Nov 29, 2023 at 07:16:52PM +0100, Mikulas Patocka wrote:
>> >
>> >
>> >On Wed, 29 Nov 2023, Sasha Levin wrote:
>> >
>> >> On Wed, Nov 29, 2023 at 06:28:16PM +0100, Mikulas Patocka wrote:
>> >> >
>> >> >
>> >> >On Wed, 29 Nov 2023, Christian Loehle wrote:
>> >> >
>> >> >> Hi Mikulas,
>> >> >> Agreed and thanks for fixing.
>> >> >> Has this been selected for stable because of:
>> >> >> 6fc45b6ed921 ("dm-delay: fix a race between delay_presuspend and
>> >> >> delay_bio")
>> >> >> If so, I would volunteer do the backports for that for you at least.
>> >> >
>> >> >I wouldn't backport this patch - it is an enhancement, not a bugfix, so it
>> >> >doesn't qualify for the stable kernel backports.
>> >>
>> >> Right - this watch was selected as a dependency for 6fc45b6ed921
>> >> ("dm-delay: fix a race between delay_presuspend and delay_bio").
>> >>
>> >> In general, unless it's impractical, we'd rather take a dependency chain
>> >> rather than deal with a non-trivial backport as those tend to have
>> >> issues longer term.
>> >>
>> >> --
>> >> Thanks,
>> >> Sasha
>> >
>> >The patch 70bbeb29fab0 ("dm delay: for short delays, use kthread instead
>> >of timers and wq") changes behavior of dm-delay from using timers to
>> >polling, so it may cause problems to people running legacy kernels - the
>> >polling consumes more CPU time than the timers - so I think it shouldn't
>> >go to the stable kernels where users expect that there will be no
>> >functional change.
>> >
>> >Here I'm submitting the patch 6fc45b6ed921 backported for 6.6.3.
>>
>> Is this okay for 6.1 too?
>
>Yes, it is. It applies to kernels as old as 4.19.

Great, applied all the way back to 4.19. Thanks!

-- 
Thanks,
Sasha