From: Andreas Larsson <andreas@gaisler.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Linux regressions mailing list <regressions@lists.linux.dev>
Cc: Nick Bowler <nbowler@draconx.ca>,
linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
sparclinux@vger.kernel.org, Sam Ravnborg <sam@ravnborg.org>
Subject: Re: PROBLEM: Only one CPU active on Ultra 60 since ~4.8 (regression)
Date: Fri, 5 Apr 2024 17:05:49 +0200 [thread overview]
Message-ID: <5f022f30-e1f2-46e3-b75b-0cb4b157448e@gaisler.com> (raw)
In-Reply-To: <CAHk-=wgFuoHpMk_Z_R3qMXVDgq0N1592+bABkyGjwwSL4zBtHA@mail.gmail.com>
On 2024-03-28 21:09, Linus Torvalds wrote:
> On Thu, 28 Mar 2024 at 12:36, Linux regression tracking (Thorsten
> Leemhuis) <regressions@leemhuis.info> wrote:
>>
>> [CCing Linus, in case I say something to his disliking]
>>
>> On 22.03.24 05:57, Nick Bowler wrote:
>>>
>>> Just a friendly reminder that this issue still happens on Linux 6.8 and
>>> reverting commit 9b2f753ec237 as indicated below is still sufficient to
>>> resolve the problem.
>>
>> FWIW, that commit 9b2f753ec23710 ("sparc64: Fix cpu_possible_mask if
>> nr_cpus is set") is from v4.8. Reverting it after all that time might
>> easily lead to even bigger trouble.
>
> I'm definitely not reverting a patch from almost a decade ago as a regression.
>
> If it took that long to find, it can't be that critical of a regression.
>
> So yes, let's treat it as a regular bug. And let's bring in Andreas to
> the discussion too (although presumably he has seen it on the
> sparclinux mailing list).
Yes, I am aware and I agree we should treat it as a regular bug.
Reverting it as a regression fix would lead to followup issues like
canceling the effect of commit ebb99a4c12e4 ("sparc64: Fix irq stack
bootmem allocation.") but with misleading comments left in place.
Sam's fix looks like a good solution for me to pick up to my
for-next branch.
Thanks,
Andreas
prev parent reply other threads:[~2024-04-05 15:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CADyTPEwt=ZNams+1bpMB1F9w_vUdPsGCt92DBQxxq_VtaLoTdw@mail.gmail.com>
[not found] ` <CADyTPEyAidGgBT3f1VJLHb3ouO-r1UyvFp1PcwXxy0NRG94sbw@mail.gmail.com>
2023-01-21 13:31 ` PROBLEM: Only one CPU active on Ultra 60 since ~4.8 (regression) Linux kernel regression tracking (Thorsten Leemhuis)
2024-03-22 4:57 ` Nick Bowler
2024-03-28 19:36 ` Linux regression tracking (Thorsten Leemhuis)
2024-03-28 20:09 ` Linus Torvalds
2024-03-28 21:08 ` Nick Bowler
2024-03-29 9:44 ` Sam Ravnborg
2024-03-29 20:11 ` Nick Bowler
2024-03-30 9:16 ` Sam Ravnborg
2024-04-05 15:05 ` Andreas Larsson [this message]
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