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authorMauro Carvalho Chehab <mchehab@redhat.com>2009-09-24 17:28:50 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-05-10 11:49:30 -0300
commit35be95446734cbb10b088a6b38269ac4a8ac3a86 (patch)
tree3c271b0454d00fe3d2eb03b12c17ae86fb30e64c /Documentation/edac.txt
parentf338d736910edf00e8426ee4322cfda585268d50 (diff)
downloadlinux-35be95446734cbb10b088a6b38269ac4a8ac3a86.tar.gz
Documentation/edac.txt: Reflect the sysfs changes at the document
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/edac.txt')
-rw-r--r--Documentation/edac.txt56
1 files changed, 29 insertions, 27 deletions
diff --git a/Documentation/edac.txt b/Documentation/edac.txt
index bd3f8a3905a..0b875e8da96 100644
--- a/Documentation/edac.txt
+++ b/Documentation/edac.txt
@@ -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