edac.txt

linux2.6.16版本

	This attribute file displays, in count of megabytes, of memory
	that this instance of memory controller manages.


Total Uncorrectable Errors count attribute file:

	'ue_count'

	This attribute file displays the total count of uncorrectable
	errors that have occurred on this memory controller. If panic_on_ue
	is set this counter will not have a chance to increment,
	since EDAC will panic the system.


Total UE count that had no information attribute fileY:

	'ue_noinfo_count'

	This attribute file displays the number of UEs that
	have occurred have occurred with  no informations as to which DIMM
	slot is having errors.


Total Correctable Errors count attribute file:

	'ce_count'

	This attribute file displays the total count of correctable
	errors that have occurred on this memory controller. This
	count is very important to examine. CEs provide early
	indications that a DIMM is beginning to fail. This count
	field should be monitored for non-zero values and report
	such information to the system administrator.


Total Correctable Errors count attribute file:

	'ce_noinfo_count'

	This attribute file displays the number of CEs that
	have occurred wherewith no informations as to which DIMM slot
	is having errors. Memory is handicapped, but operational,
	yet no information is available to indicate which slot
	the failing memory is in. This count field should be also
	be monitored for non-zero values.

Device Symlink:

	'device'

	Symlink to the memory controller device



============================================================================
'csrowX' DIRECTORIES

In the 'csrowX' directories are EDAC control and attribute files for
this 'X" instance of csrow:


Total Uncorrectable Errors count attribute file:

	'ue_count'

	This attribute file displays the total count of uncorrectable
	errors that have occurred on this csrow. If panic_on_ue is set
	this counter will not have a chance to increment, since EDAC
	will panic the system.


Total Correctable Errors count attribute file:

	'ce_count'

	This attribute file displays the total count of correctable
	errors that have occurred on this csrow. This
	count is very important to examine. CEs provide early
	indications that a DIMM is beginning to fail. This count
	field should be monitored for non-zero values and report
	such information to the system administrator.


Total memory managed by this csrow attribute file:

	'size_mb'

	This attribute file displays, in count of megabytes, of memory
	that this csrow contatins.


Memory Type attribute file:

	'mem_type'

	This attribute file will display what type of memory is currently
	on this csrow. Normally, either buffered or unbuffered memory.


EDAC Mode of operation attribute file:

	'edac_mode'

	This attribute file will display what type of Error detection
	and correction is being utilized.


Device type attribute file:

	'dev_type'

	This attribute file will display what type of DIMM device is
	being utilized. Example:  x4


Channel 0 CE Count attribute file:

	'ch0_ce_count'

	This attribute file will display the count of CEs on this
	DIMM located in channel 0.


Channel 0 UE Count attribute file:

	'ch0_ue_count'

	This attribute file will display the count of UEs on this
	DIMM located in channel 0.


Channel 0 DIMM Label control file:

	'ch0_dimm_label'

	This control file allows this DIMM to have a label assigned
	to it. With this label in the module, when errors occur
	the output can provide the DIMM label in the system log.
	This becomes vital for panic events to isolate the
	cause of the UE event.

	DIMM Labels must be assigned after booting, with information
	that correctly identifies the physical slot with its
	silk screen label. This information is currently very
	motherboard specific and determination of this information
	must occur in userland at this time.


Channel 1 CE Count attribute file:

	'ch1_ce_count'

	This attribute file will display the count of CEs on this
	DIMM located in channel 1.


Channel 1 UE Count attribute file:

	'ch1_ue_count'

	This attribute file will display the count of UEs on this
	DIMM located in channel 0.


Channel 1 DIMM Label control file:

	'ch1_dimm_label'

	This control file allows this DIMM to have a label assigned
	to it. With this label in the module, when errors occur
	the output can provide the DIMM label in the system log.
	This becomes vital for panic events to isolate the
	cause of the UE event.

	DIMM Labels must be assigned after booting, with information
	that correctly identifies the physical slot with its
	silk screen label. This information is currently very
	motherboard specific and determination of this information
	must occur in userland at this time.


============================================================================
SYSTEM LOGGING

If logging for UEs and CEs are enabled then system logs will have
error notices indicating errors that have been detected:

MC0: CE page 0x283, offset 0xce0, grain 8, syndrome 0x6ec3, row 0,
channel 1 "DIMM_B1": amd76x_edac

MC0: CE page 0x1e5, offset 0xfb0, grain 8, syndrome 0xb741, row 0,
channel 1 "DIMM_B1": amd76x_edac


The structure of the message is:
	the memory controller			(MC0)
	Error type				(CE)
	memory page				(0x283)
	offset in the page			(0xce0)
	the byte granularity 			(grain 8)
		or resolution of the error
	the error syndrome			(0xb741)
	memory row				(row 0)
	memory channel				(channel 1)
	DIMM label, if set prior		(DIMM B1
	and then an optional, driver-specific message that may
		have additional information.

Both UEs and CEs with no info will lack all but memory controller,
error type, a notice of "no info" and then an optional,
driver-specific error message.



============================================================================
PCI Bus Parity Detection


On Header Type 00 devices the primary status is looked at
for any parity error regardless of whether Parity is enabled on the
device.  (The spec indicates parity is generated in some cases).
On Header Type 01 bridges, the secondary status register is also
looked at to see if parity ocurred on the bus on the other side of
the bridge.


SYSFS CONFIGURATION

Under /sys/devices/system/edac/pci are control and attribute files as follows:


Enable/Disable PCI Parity checking control file:

	'check_pci_parity'


	This control file enables or disables the PCI Bus Parity scanning
	operation. Writing a 1 to this file enables the scanning. Writing
	a 0 to this file disables the scanning.

	Enable:
	echo "1" >/sys/devices/system/edac/pci/check_pci_parity

	Disable:
	echo "0" >/sys/devices/system/edac/pci/check_pci_parity



Panic on PCI PARITY Error:

	'panic_on_pci_parity'


	This control files enables or disables panic'ing when a parity
	error has been detected.


	module/kernel parameter: panic_on_pci_parity=[0|1]

	Enable:
	echo "1" >/sys/devices/system/edac/pci/panic_on_pci_parity

	Disable:
	echo "0" >/sys/devices/system/edac/pci/panic_on_pci_parity


Parity Count:

	'pci_parity_count'

	This attribute file will display the number of parity errors that
	have been detected.



PCI Device Whitelist:

	'pci_parity_whitelist'

	This control file allows for an explicit list of PCI devices to be
	scanned for parity errors. Only devices found on this list will
	be examined.  The list is a line of hexadecimel VENDOR and DEVICE
	ID tuples:

	1022:7450,1434:16a6

	One or more can be inserted, seperated by a comma.

	To write the above list doing the following as one command line:

	echo "1022:7450,1434:16a6"
		> /sys/devices/system/edac/pci/pci_parity_whitelist



	To display what the whitelist is, simply 'cat' the same file.


PCI Device Blacklist:

	'pci_parity_blacklist'

	This control file allows for a list of PCI devices to be
	skipped for scanning.
	The list is a line of hexadecimel VENDOR and DEVICE ID tuples:

	1022:7450,1434:16a6

	One or more can be inserted, seperated by a comma.

	To write the above list doing the following as one command line:

	echo "1022:7450,1434:16a6"
		> /sys/devices/system/edac/pci/pci_parity_blacklist


	To display what the whitelist current contatins,
	simply 'cat' the same file.

=======================================================================

PCI Vendor and Devices IDs can be obtained with the lspci command. Using
the -n option lspci will display the vendor and device IDs. The system
adminstrator will have to determine which devices should be scanned or
skipped.



The two lists (white and black) are prioritized. blacklist is the lower
priority and will NOT be utilized when a whitelist has been set.
Turn OFF a whitelist by an empty echo command:

	echo > /sys/devices/system/edac/pci/pci_parity_whitelist

and any previous blacklist will be utililzed.