On 02.08.2012, Georgios Petasis wrote:
So, this is a processor bug? I would expect that Linux should detect
these
automatically...
If I remember all correctly, there were two mainly independend issues
with C1E in Linux, one which is processor-related, and one
BIOS-related. Processor-bugs are adressed by loading fixes via
microcode updates at boot-time. Check your dmesg output if this is the
case with your CPU. There should be something like that (laptop with
i5 cpu):
[root@wildsau ~]# dmesg | grep microcode
microcode: CPU0 sig=0x20655, pf=0x10, revision=0x2
microcode: CPU0 updated to revision 0x3, date = 2011-09-01
microcode: CPU1 sig=0x20655, pf=0x10, revision=0x2
microcode: CPU1 updated to revision 0x3, date = 2011-09-01
microcode: CPU2 sig=0x20655, pf=0x10, revision=0x2
microcode: CPU2 updated to revision 0x3, date = 2011-09-01
microcode: CPU3 sig=0x20655, pf=0x10, revision=0x2
microcode: CPU3 updated to revision 0x3, date = 2011-09-01
microcode: Microcode Update Driver: v2.00
<tigran@xxxxxxxxxxxxxxxxxxxx>, Peter Oruba
So, my AMD 920 cpu is not only slow, it has also some errata
incompatible
with Fedora. Nice :D
Nearly all CPUs have errata :-)
The problem you encounter is not a Fedora one, it's most likely a
BIOS-problem, or the E400 routines in the kernel doesn't get triggered
by your hardware. It's impossible for me to see where the problem
finally originates in your case. The AMD people are generally cute
ones and really
interested in such thing, so if you care to dig into this further, you
could consider mailing Borislav Petkov directly
(borislav.petkov@xxxxxxx).
If I remember that right, there was a fix pending around april/may
2011 for this, and a quick look into process.c shows that the E400
case is taken care of by the kernel. Look into your dmesg output and
boot.log (and other logfiles: /var/log/messages etc.) for "AMD E400
aware idle routine" or something similar/related.
