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

[Matthew Wilcox]

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:
> > > #regzbot introduced v5.19-rc6..1dd685c414a7b9fdb3d23aca3aedae84f0b998ae
> > >
> > > 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?