After upgrading to 2.6.37, I started having frequent error messages like those shown below, about MCE. This happens in all terminals, in a Debian sid box that did (and does) not show this behavior with 2.6.35 (just some "[Hardware Error]: Machine check events logged" messages at syslog). Already reported to Debian, http://bugs.debian.org/613973 and suggested to report that here too. Messages follow: [ 300.004017] [Hardware Error]: No human readable MCE decoding support on this CPU type. [ 300.004025] [Hardware Error]: Run the message through 'mcelog --ascii' to decode. [ 300.004028] Disabling lock debugging due to kernel taint [ 300.004031] [Hardware Error]: No human readable MCE decoding support on this CPU type. [ 300.004033] [Hardware Error]: Run the message through 'mcelog --ascii' to decode. [ 300.004036] [Hardware Error]: Machine check events logged Browsing a bit about this, seems that Andi Kleen patch in his mce branch http://git.kernel.org/?p=linux/kernel/git/ak/linux-mce-2.6.git;a=commitdiff h=6e3c7411d2b86bff210c59caa432e8e862037bfd is related to this problem. I found that patch after reading last question in http://www.mcelog.org/faq.html This problem is still in at least 2.6.38-rc6 (I'd expect it in rc7 too, reading 2.6.38-rc7 changelog I see neither merging from Andi Kleen linux-mce-2.6 nor references to MCE) Processor at this box is an AMD Athlon XP 2800+
I have encountered the same problem using Gentoo kernels 2.6.37 & 2.6.38 & the vanilla kernel 2.6.38.2 . It is avoided with 'append="nomce"'. The messages involved should never be sent to a user's terminal & only subject to an option should be sent to root's terminals. I will attach screenshots showing what happens in all running terminals & my kernel .config . Below is my original bug report to Gentoo http://bugs.gentoo.org/show_bug.cgi?id=352372 : "I recently upgraded my kernel from 2.6.33 to 2.6.37 & began to receive multiple messages in every terminal (Konsole & XFCE's Terminal) saying kernel: [Hardware Error]: No human readable MCE decoding support on this CPU type. kernel: [Hardware Error]: Run the message through 'mcelog --ascii' to decode. these messages also occur in the Syslog file with the added line kernel: [Hardware Error]: Machine check events logged This 3rd line used to occur in Syslog also when using 2.6.33, but not the others & none of the lines was written to any terminal I was running. The messages can be eradicated by booting with 'append="nomce"', but that appears to stop the whole MCE process, not just the messages. Looking through the kernel configuration with 'make menuconfig' suggests that the problem is that CONFIG_EDAC_DECODE_MCE is what is needed, but as the help states "Decode MCEs in human-readable form (only on AMD for now)". My machine has an Intel Core2 Duo processor".
Created attachment 54022 [details] kernel .config file for 2.6.38.2 This is the .config file for Gentoo & vanilla 2.6.38 kernels I used.
Created attachment 54032 [details] result of Gentoo 'emerge --info' This shows details of my system set-up.
Created attachment 54042 [details] screenshot of spurious messages on root terminal
Created attachment 54052 [details] screenshot of spurious messages on user's Konsole
Created attachment 54062 [details] screenshot of spurious messages on user's Konsole running Mutt
Seems fixed with 3.0