Re: [REGRESSION] XArray commit prevents booting with 6.0-rc1 or later

From: Thorsten Leemhuis
Date: Mon Dec 12 2022 - 02:04:09 EST


On 28.11.22 13:18, Matthew Wilcox wrote:
> On Sun, Nov 20, 2022 at 12:20:13AM +0100, Jorropo wrote:
>> Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote :
>>> On Sat, Nov 19, 2022 at 05:07:45AM +0100, Jorropo wrote:
>>>>
>>>> Hi, I recently tried to upgrade to linux v6.0.x but when trying to
>>>> boot it fails with "error: out of memory" when or after loading
>>>> initramfs (which then kpanics because the vfs root is missing).
>>>> The latest releases I tested are v6.0.9 and v6.1-rc5 and it's broken there too.
>>>>
>>>> I bisected the error to this patch:
>>>> 1dd685c414a7b9fdb3d23aca3aedae84f0b998ae "XArray: Add calls to
>>>> might_alloc()" is the first bad commit.
>>>> I've confirmed this is not a side effect of a poor bitsect because
>>>> 1dd685c414a7b9fdb3d23aca3aedae84f0b998ae~1 (v5.19-rc6) works.
>>>
>>> That makes no sense. I can't look into this until Wednesday, but I
>>> suggest that what you have is an intermittent failure to boot, and
>>> the bisect has led you down the wrong path.
>>
>> I rebuilt both 1dd685c414a7b9fdb3d23aca3aedae84f0b998ae and
>> the parent commit (v5.19-rc6), then tried to start each one 8 times
>> (shuffled in a Thue morse sequence).
>> 0 successes for 1dd685c414a7b9fdb3d23aca3aedae84f0b998ae
>> 8 successes for v5.19-rc6
>>
>> This really does not look like an intermittent issue.
>
> OK, you convinced me. Can you boot 1dd685c414 with the command line
> parameters "debug initcall_debug" so we get more information?

Jorropo, did you ever provide the information Matthew asked for? I'm
asking, as this looks stalled -- and I wonder why. Or was progress made
somewhere and I just missed it?

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.

#regzbot poke