Gentoo Archives: gentoo-user

From: Fernando Rodriguez <cyklonite@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Boot freeze/kthreadd stack trace - AMD_PMU_INIT
Date: Mon, 28 Nov 2016 12:01:01
In Reply to: [gentoo-user] Boot freeze/kthreadd stack trace - AMD_PMU_INIT by ""
1 On 11/21/2016 01:15 AM, Taiidan@×××.com wrote:
2 > Specs:
3 > blob free coreboot on a kgpe-d16 (amd opteron)
4 >
5 >
6 > Happens with both the livecd/usb and a kernel I compiled on another
7 > machine (however with that one I simply get a black screen and a bootloop)
9 Look at CONFIG_PANIC_TIMEOUT. If it's set to anything other than 0 your
10 kernel will reboot itself on panic after the timeout. It's probably
11 panicing when initialing the video drivers since you get a blank screen
12 so you'll probably want to boot with a vga fb driver (blacklist or
13 delete all other video modules) and post the backtrace if it still panics.
16 > Other distros kernels work fine, it is just gentoo.
18 Then I suggest you try grabbing the kernel's config file from another
19 distro and use that as a starting point to configure your kernel
21 > The livecd and compiled kernel work fine on all my other computers/VMM's.
22 >
23 > Upon loading I get to amd performance counters, it freezes and 5-10 secs
24 > later I receive stack trace for kthreadd "hung" (amd_pmu_init - seems to
25 > be the primary reason) I never get to a login prompt.
26 >
27 > It isn't microcode related as I removed the microcode packages from the
28 > other distros I tried.
29 >
30 > Any ideas? Is there any additional info that would be helpful? How can I
31 > dump the boot text?
33 It's gonna be trial and error. Keep disabling features and try a
34 different kernel version (the one that worked with other distros) until
35 you pinpoint the problem. The only hints you got are the panic backtrces
36 and boot output. Then file a bug.
38 As for dumping the boot output if you can't get to userland I think the
39 only way is with a serial or net console. Also look at
40 CONFIG_BOOT_PRINTK_DELAY, it can setup a delay before every printk
41 message so you at least get time to read it.
43 --
45 Fernando Rodriguez