FS#31606 - [linux] 3.5.3 - 3.9.x cpu cores : 0

Attached to Project: Arch Linux
Opened by Alfredo Amatriain (amatriain) - Wednesday, 19 September 2012, 09:06 GMT
Last edited by Tobias Powalowski (tpowa) - Monday, 06 May 2013, 13:29 GMT
Task Type Bug Report
Category Upstream Bugs
Status Closed
Assigned To Tobias Powalowski (tpowa)
Thomas Bächler (brain0)
Architecture All
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 1
Private No

Details

In an LG X110 netbook when I try to run lscpu it crashes with a "Floating point exception" message:

$ lscpu
Floating point exception

I get nothing of relevance in /var/log/messages.log , /var/log/everything.log or journalctl.

I have util-linux 2.21.2-5 installed:

$ pacman -Qs util-linux
local/util-linux 2.21.2-5 (base)

This is the output from /proc/cpuinfo:

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz
stepping : 2
microcode : 0x20a
cpu MHz : 800.000
cache size : 512 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm dtherm
bogomips : 3201.53
clflush size : 64
cache_alignment : 64
address sizes : 32 bits physical, 32 bits virtual
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 28
model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz
stepping : 2
microcode : 0x20a
cpu MHz : 800.000
cache size : 512 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 0
apicid : 1
initial apicid : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm dtherm
bogomips : 3201.53
clflush size : 64
cache_alignment : 64
address sizes : 32 bits physical, 32 bits virtual
power management:
This task depends upon

Closed by  Tobias Powalowski (tpowa)
Monday, 06 May 2013, 13:29 GMT
Reason for closing:  Upstream
Comment by Alexander F. Rødseth (xyproto) - Wednesday, 19 September 2012, 09:27 GMT
There's a new version of util-linux in [testing]. Could you please test if it solves this problem? Thanks.
Comment by Daniel Wallace (gtmanfred) - Wednesday, 19 September 2012, 09:33 GMT
I had the same bug, new version of util-linux fixes it here
Comment by Alexander F. Rødseth (xyproto) - Wednesday, 19 September 2012, 09:42 GMT
Assume this is fixed in testing, then. Leave this one open until the package leaves testing?
Comment by Alfredo Amatriain (amatriain) - Wednesday, 19 September 2012, 10:20 GMT
When trying to install util-linux from [testing], I get file conflicts:

$ sudo pacman -S util-linux
resolving dependencies...
looking for inter-conflicts...
:: util-linux and eject are in conflict. Remove eject? [y/N] y

Targets (2): eject-2.1.5-7 [removal] util-linux-2.22-5

Total Installed Size: 8.66 MiB
Net Upgrade Size: 1.30 MiB

Proceed with installation? [Y/n]
(1/1) checking package integrity [######################] 100%
(1/1) loading package files [######################] 100%
(1/1) checking for file conflicts [######################] 100%
error: failed to commit transaction (conflicting files)
util-linux: /bin/kill exists in filesystem
util-linux: /bin/su exists in filesystem
util-linux: /etc/pam.d/su exists in filesystem
util-linux: /sbin/sulogin exists in filesystem
util-linux: /usr/bin/mesg exists in filesystem
util-linux: /usr/bin/utmpdump exists in filesystem
util-linux: /usr/bin/wall exists in filesystem
util-linux: /usr/share/man/man1/kill.1.gz exists in filesystem
util-linux: /usr/share/man/man1/mesg.1.gz exists in filesystem
util-linux: /usr/share/man/man1/su.1.gz exists in filesystem
util-linux: /usr/share/man/man1/utmpdump.1.gz exists in filesystem
util-linux: /usr/share/man/man1/wall.1.gz exists in filesystem
util-linux: /usr/share/man/man8/sulogin.8.gz exists in filesystem
Errors occurred, no packages were upgraded.


Some of those files are quite critical (/bin/su for instance), so I'm a bit nervous about trying to fix it manually. Should I update other packages from [testing] before updating util-linux?
Comment by Tom Gundersen (tomegun) - Wednesday, 19 September 2012, 10:54 GMT
@Alfredo: cherry-picking packages from testing is generally a bad idea (unless you know which ones you need).

I think installing coreutils + sysvinit + sysvinit-tools + procps-ng + util-linux should be sufficient. However, a safer option is to either just wait for it to reach core or to enable all of testing.
Comment by Dave Reisner (falconindy) - Wednesday, 19 September 2012, 12:45 GMT
This isn't fixed in testing because it's caused by a kernel bug. Your second cpu has 0 cores, according to /proc/cpuinfo.
Comment by Alfredo Amatriain (amatriain) - Wednesday, 19 September 2012, 12:55 GMT
Is it a known bug? I'm pretty sure my netbook has just one single-core cpu.
I'm running linux package version 3.5.4-1

$ uname -r
3.5.4-1-ARCH
Comment by Alexander F. Rødseth (xyproto) - Wednesday, 19 September 2012, 13:26 GMT
Alfredo, this is how it's supposed to look:
http://wiki.gentoo.org/wiki/Asus_Eee_PC_1000H#CPU

Notice: "cpu cores : 1" for both entries.

Your processor does not have two cores, but pretends to, with Hyperthreading (HT).

I think Dave nailed it. Well spotted, Dave!
Comment by Evangelos Foutras (foutrelis) - Friday, 21 September 2012, 18:15 GMT
Sounds like the kernel bug I've filed:

https://bugzilla.kernel.org/show_bug.cgi?id=46001
Comment by Alfredo Amatriain (amatriain) - Saturday, 22 September 2012, 09:29 GMT
@foutrelis I added a comment to the bug you posted in the upstream bugtracker. It looks like an upstream bug.
Comment by Tobias Powalowski (tpowa) - Wednesday, 23 January 2013, 15:03 GMT
Status on 3.7.x?
Comment by Alfredo Amatriain (amatriain) - Wednesday, 23 January 2013, 20:44 GMT
Since the last kernel upgrade (from 3.6.9 to 3.7.3) I've been unable to succesfully boot the machine in which this bug happens using the latest kernel. Currently I can only boot it with the latest linux-lts (currently 3.0.59), in which the bug doesn't happen.

I will dig a bit but if I cannot boot the machine with 3.7.3 I obviously won't be able to confirm it either way.
Comment by Tobias Powalowski (tpowa) - Wednesday, 27 February 2013, 11:10 GMT
Status on 3.8?
Comment by Evangelos Foutras (foutrelis) - Wednesday, 27 February 2013, 11:33 GMT
Bug still exists in 3.8 and the upstream report [1] hasn't received any attention from kernel devs.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=46001
Comment by Alfredo Amatriain (amatriain) - Wednesday, 27 February 2013, 19:40 GMT
With kernel 3.7.9-2 lscpu no longer crashes.
However /proc/cpuinfo still reports 0 cores in the second cpu.
Not solved in 3.7.

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