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Documentation/edac.txt: Reflect the sysfs changes at the document

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Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Mauro Carvalho Chehab 2009-09-24 17:28:50 -03:00
parent f338d73691
commit 35be954467
1 changed files with 29 additions and 27 deletions
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56
Documentation/edac.txt
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@ -766,7 +766,7 @@ exports one
For injecting a memory error, there are some sysfs nodes, under
/sys/devices/system/edac/mc/mc?/:
inject_addrmatch:
inject_addrmatch/*:
Controls the error injection mask register. It is possible to specify
several characteristics of the address to match an error code:
dimm = the affected dimm. Numbers are relative to a channel;
@ -781,10 +781,12 @@ exports one
For example, to generate an error at rank 1 of dimm 2, for any channel,
any bank, any page, any column:
echo "dimm:2 rank:1" >/sys/devices/system/edac/mc/mc0/inject_addrmatch
echo 2 >/sys/devices/system/edac/mc/mc0/inject_addrmatch/dimm
echo 1 >/sys/devices/system/edac/mc/mc0/inject_addrmatch/rank
To return to the default behaviour of matching any, you can do:
echo "dimm:any rank:any" >/sys/devices/system/edac/mc/mc0/inject_addrmatch
echo any >/sys/devices/system/edac/mc/mc0/inject_addrmatch/dimm
echo any >/sys/devices/system/edac/mc/mc0/inject_addrmatch/rank
inject_eccmask:
specifies what bits will have troubles,
@ -813,7 +815,7 @@ exports one
For example, the following code will generate an error for any write access
at socket 0, on any DIMM/address on channel 2:
echo "channel:2" > /sys/devices/system/edac/mc/mc0/inject_addrmatch
echo 2 >/sys/devices/system/edac/mc/mc0/inject_addrmatch/channel
echo 2 >/sys/devices/system/edac/mc/mc0/inject_type
echo 64 >/sys/devices/system/edac/mc/mc0/inject_eccmask
echo 3 >/sys/devices/system/edac/mc/mc0/inject_section
@ -829,18 +831,23 @@ exports one
3) Nehalem specific Corrected Error memory counters
Nehalem have some registers to count memory errors, reporting it on a
way that it is different from what EDAC API allows. Due to that, a
separate sysfs note were created to handle such counters.
Nehalem have some registers to count memory errors. The driver uses those
registers to report Corrected Errors on devices with Registered Dimms.
They can be read by looking at the contents of "corrected_error_counts"
counter. Due to hardware limits, the output is different on machines
with unregistered memories and machines with registered ones.
However, those counters don't work with Unregistered Dimms. As the chipset
offers some counters that also work with UDIMMS (but with a worse level of
granularity than the default ones), the driver exposes those registers for
UDIMM memories.
With unregistered memories, it outputs:
They can be read by looking at the contents of all_channel_counts/
$ cat /sys/devices/system/edac/mc/mc0/corrected_error_counts
all channels UDIMM0: 0 UDIMM1: 0 UDIMM2: 0
$ for i in /sys/devices/system/edac/mc/mc0/all_channel_counts/*; do echo $i; cat $i; done
/sys/devices/system/edac/mc/mc0/all_channel_counts/udimm0
0
/sys/devices/system/edac/mc/mc0/all_channel_counts/udimm1
0
/sys/devices/system/edac/mc/mc0/all_channel_counts/udimm2
0
What happens here is that errors on different csrows, but at the same
dimm number will increment the same counter.
@ -849,21 +856,16 @@ exports one
csrow1: channel 0, dimm1
csrow2: channel 1, dimm0
csrow3: channel 2, dimm0
The hardware will increment UDIMM0 for an error at either csrow0, csrow2
or csrow3.
With registered memories, it outputs:
$cat /sys/devices/system/edac/mc/mc0/corrected_error_counts
channel 0 RDIMM0: 0 RDIMM1: 0 RDIMM2: 0
channel 1 RDIMM0: 0 RDIMM1: 0 RDIMM2: 0
channel 2 RDIMM0: 0 RDIMM1: 0 RDIMM2: 0
So, with registered memories, there's a direct map between a csrow and a
counter.
The hardware will increment udimm0 for an error at the first dimm at either
csrow0, csrow2 or csrow3;
The hardware will increment udimm1 for an error at the second dimm at either
csrow0, csrow2 or csrow3;
The hardware will increment udimm2 for an error at the third dimm at either
csrow0, csrow2 or csrow3;
4) Standard error counters
The standard error counters are generated when an mcelog error is received
by the driver. Since it is counted by software, it is possible that some
errors could be lost.
by the driver. Since, with udimm, this is counted by software, it is
possible that some errors could be lost. With rdimm's, they displays the
contents of the registers