Subject: Re: 4.14.9 doesn't boot (regression)
To: Linus Torvalds <torvalds@linux-foundation.org>,
        Alexander Tsoy <alexander@tsoy.me>
Cc: Andy Lutomirski <luto@amacapital.net>, stable <stable@vger.kernel.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        the arch/x86 maintainers <x86@kernel.org>
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 <CA+55aFyJiCT=Mnn5RUMiYRXddi_eSdVTpobEKNoHzYXsos_6pw@mail.gmail.com>
From: =?UTF-8?Q?Toralf_F=c3=b6rster?= <toralf.foerster@gmx.de>
Message-ID: <a591188f-021b-6d0a-6261-28fa83d161e1@gmx.de>
Date: Fri, 29 Dec 2017 23:30:08 +0100
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On 12/29/2017 10:17 PM, Linus Torvalds wrote:
> On Fri, Dec 29, 2017 at 1:02 PM, Toralf Förster <toralf.foerster@gmx.de> wrote:
>> On 12/29/2017 09:12 PM, Linus Torvalds wrote:
>>> instead, and see if that makes a difference, that would narrow down
>>> the possible root cause of this problem.
>>
>> not at this ThinkPad T440s (didn't test at the server with an i7-3930).
>>
>> Boot stops just at:
>>
>>         tsc: Refined TSC clocksource calibration: 2494.225 MHz
>>         clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x23f3ea95b09, max_idle_ns: 440795287034 ns
> 
> Uhhuh. So for Alexander Troy, just getting rid of the -march=core2
> fixed the boot.
> 
> But not for you.
> 
> Strange. It really looked like the exact same thing.
> 
>> This is a "Intel(R) Core(TM) i5-4300U CPU @ 1.90GHz" with gcc-6.4
> 
> Yeah, other reporters of this have used gcc-6.4.0 too.
> 
> But there's been some muddying of the waters there too - changing
> compilers have fixed it for some cases, but there's at least one
> report that a kernel build with gcc-7.2.0 still had the issue (and
> another that said it didn't).
> 
> But the MCORE2 was consistent for several people - including you.
> Until this point.
> 
> Strange.
> 
> The only other thing (apart from the compiler flag) that MCORE2
> results in is to enable
> 
>  CONFIG_X86_INTEL_USERCOPY
>  CONFIG_X86_USE_PPRO_CHECKSUM
>  CONFIG_X86_P6_NOP
> 
> and the two first of those shouldn't even matter on x86-64, and I
> don't see that last one making any difference either.
> 
> So because it looks so impossible that the "-march=core2" didn't make
> a difference for you, I'll ask you to please double-check that you
> actually booted into the right kernel.
> 
> Sorry for doubting you, but your report just broke the _one_
> consistent thing we've seen about this bug.
> 
>               Linus
> 


I double-checked it.

The bad news - the issue is not solved with the changed cflags.
The good news - I could compile eventually a working config for my desktop  (works fine with 4.14.10 with generic CPU) having a higher screen resolution during boot.

So I made a "make distclean", followed by a "sudo zcat /proc/config.gz > .config", changed the .config to use MCORE2 instead of GENERIC and defined the string "-local" to ensure that the modules directory is really unique.
Then I run "time make -j4 && sudo make modules_install && sudo cp arch/x86_64/boot/bzImage /boot/vmlinuz-0 && sudo grub-mkconfig -o /boot/grub/grub.cfg", booted and made 3 fotos which were uploaded to [1], look for IMG_*

[1] https://zwiebeltoralf.de/pub/


-- 
Toralf
PGP C4EACDDE 0076E94E