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 <20220211124302.7b0f0ec0@canb.auug.org.au>
In-Reply-To: <20220211124302.7b0f0ec0@canb.auug.org.au>
From:   Tong Zhang <ztong0001@gmail.com>
Date:   Fri, 11 Feb 2022 09:36:17 -0800
Message-ID: <CAA5qM4Der1X+sESjPY0eQ-Qo_x0YEYZLo7d6Xjk6fPc1zXzZcA@mail.gmail.com>
Subject: Re: linux-next: boottime warning from todays linux-next
To:     Stephen Rothwell <sfr@canb.auug.org.au>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Domenico Andreoli <domenico.andreoli@linux.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Next Mailing List <linux-next@vger.kernel.org>
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On Thu, Feb 10, 2022 at 5:43 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Tong,
>
> On Thu, 10 Feb 2022 15:35:30 -0800 Tong Zhang <ztong0001@gmail.com> wrote:
> >
> > I am trying to see if I can reproduce this.
> > Could you share the QEMU command line and pseries_le_defconfig?
> > Latest kernel does not have pseries_le_defconfig so I assume you have
> > your own version.
>
> This is a ARCH=powerpc build and qemu run.
>
> qemu-system-ppc64 -M pseries -cpu POWER8 -m 2G -vga none -nographic -kernel $vmlinux -initrd $initrd
>
> I have a simple initrd that just boots to a login prompt.
>
> Anyway, it seems that the mystery has been solved (hopefully).
> --
> Cheers,
> Stephen Rothwell

Thanks for providing the configuration.
I tried the same setup and it worked. No crash whatsoever.

As mentioned by Luis, if I enable the line below, the kernel will
throw out a similar message like in your original mail.

@@ -2773,7 +2761,6 @@ int __init sysctl_init_bases(void)
{
register_sysctl_base(kernel);
register_sysctl_base(vm);
+ register_sysctl_base(fs);
register_sysctl_base(debug);
register_sysctl_base(dev);

[    0.190779][    T1] Call Trace:
[    0.190836][    T1] [c0000000073e3a90] [c0000000007bc2e0]
dump_stack_lvl+0x74/0xa8 (unreliable)
[    0.190940][    T1] [c0000000073e3ad0] [c000000000581d9c]
__register_sysctl_table+0x59c/0x8f0
[    0.191054][    T1] [c0000000073e3bd0] [c0000000020416fc]
init_fs_stat_sysctls+0x48/0x60
[    0.191110][    T1] [c0000000073e3bf0] [c000000000012190]
do_one_initcall+0x60/0x2c0
[    0.191139][    T1] [c0000000073e3cc0] [c000000002004a24]
kernel_init_freeable+0x33c/0x3dc
[    0.191189][    T1] [c0000000073e3da0] [c0000000000127a4]
kernel_init+0x34/0x1a0
[    0.191231][    T1] [c0000000073e3e10] [c00000000000cd64]
ret_from_kernel_thread+0x5c/0x64

I believe this issue can be marked as resolved now.

- Tong