svn commit: r192050 - in head/sys: amd64/amd64 amd64/include
conf i386/i386 i386/include
alc at cs.rice.edu
Sat May 16 18:39:35 UTC 2009
John Baldwin wrote:
> Author: jhb
> Date: Wed May 13 17:53:04 2009
> New Revision: 192050
> URL: http://svn.freebsd.org/changeset/base/192050
> Implement simple machine check support for amd64 and i386.
> - For CPUs that only support MCE (the machine check exception) but not MCA
> (i.e. Pentium), all this does is print out the value of the machine check
> registers and then panic when a machine check exception occurs.
> - For CPUs that support MCA (the machine check architecture), the support is
> a bit more involved.
> - First, there is limited support for decoding the CPU-independent MCA
> error codes in the kernel, and the kernel uses this to output a short
> description of any machine check events that occur.
> - When a machine check exception occurs, all of the MCx banks on the
> current CPU are scanned and any events are reported to the console
> before panic'ing.
> - To catch events for correctable errors, a periodic timer kicks off a
> task which scans the MCx banks on all CPUs. The frequency of these
> checks is controlled via the "hw.mca.interval" sysctl.
> - Userland can request an immediate scan of the MCx banks by writing
> a non-zero value to "hw.mca.force_scan".
> - If any correctable events are encountered, the appropriate details
> are stored in a 'struct mca_record' (defined in <machine/mca.h>).
> The "hw.mca.count" is a count of such records and each record may
> be queried via the "hw.mca.records" tree by specifying the record
> index (0 .. count - 1) as the next name in the MIB similar to using
> PIDs with the kern.proc.* sysctls. The idea is to export machine
> check events to userland for more detailed processing.
> - The periodic timer and hw.mca sysctls are only present if the CPU
> supports MCA.
> Discussed with: emaste (briefly)
> MFC after: 1 month
> head/sys/amd64/amd64/mca.c (contents, props changed)
> head/sys/amd64/include/mca.h (contents, props changed)
> head/sys/i386/i386/mca.c (contents, props changed)
> head/sys/i386/include/mca.h (contents, props changed)
After this change my Phenom II locks up hard within minutes of booting.
There are no messages, and I am unable to break into the debugger from a
The same exact kernel is running fine on a Core 2 Quad.
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