Re: Bug 218665 - nohz_full=0 prevents kernel from booting

From: Tejun Heo
Date: Tue Apr 16 2024 - 19:21:43 EST


Hello,

On Tue, Apr 16, 2024 at 08:08:07AM +0200, Linux regression tracking (Thorsten Leemhuis) wrote:
> On 12.04.24 04:57, Bjorn Andersson wrote:
> > On Wed, Apr 10, 2024 at 11:18:04AM +0200, Linux regression tracking (Thorsten Leemhuis) wrote:
> >> On 08.04.24 00:52, Bjorn Andersson wrote:
> >>> On Tue, Apr 02, 2024 at 10:17:16AM +0200, Linux regression tracking (Thorsten Leemhuis) wrote:
> >>>>
> >>>> Tejun, apparently it's cause by a change of yours.
> >>>> Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=218665 :
> >>>>
> >>>>> booting the current kernel (6.9.0-rc1, master/712e1425) on x86_64
> >>>>> with nohz_full=0 cause a page fault and prevents the kernel from
> >>>>> booting.
> >>> [...]
>
> Tejun, I got a bit lost here. Can you help me out please?
>
> I'm currently assuming that these two reports have the same cause:
> https://lore.kernel.org/all/20240402105847.GA24832@xxxxxxxxxx/T/#u
> https://bugzilla.kernel.org/show_bug.cgi?id=218665
>
> And that both will be fixed by this patch from Oleg Nesterov:
> https://lore.kernel.org/lkml/20240411143905.GA19288@xxxxxxxxxx/
>
> But well, to me it looks like below issue from Bjorn is different, even
> if it is caused by the same change -- nevertheless it looks like nobody
> has looked into this since it was reported about two weeks ago. Or was
> progress made and I just missed it?

Can you elaborate why Bjorn's case is different? I was assuming it was the
same problem and that Oleg's fixes would address the issue.

Thanks.

--
tejun