summaryrefslogtreecommitdiff
path: root/Documentation/admin-guide/ras.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/admin-guide/ras.rst')
-rw-r--r--Documentation/admin-guide/ras.rst28
1 files changed, 15 insertions, 13 deletions
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst
index 0310db624964..7b481b2a368e 100644
--- a/Documentation/admin-guide/ras.rst
+++ b/Documentation/admin-guide/ras.rst
@@ -156,11 +156,11 @@ the labels provided by the BIOS won't match the real ones.
ECC memory
----------
-As mentioned on the previous section, ECC memory has extra bits to be
-used for error correction. So, on 64 bit systems, a memory module
-has 64 bits of *data width*, and 74 bits of *total width*. So, there are
-8 bits extra bits to be used for the error detection and correction
-mechanisms. Those extra bits are called *syndrome*\ [#f1]_\ [#f2]_.
+As mentioned in the previous section, ECC memory has extra bits to be
+used for error correction. In the above example, a memory module has
+64 bits of *data width*, and 72 bits of *total width*. The extra 8
+bits which are used for the error detection and correction mechanisms
+are referred to as the *syndrome*\ [#f1]_\ [#f2]_.
So, when the cpu requests the memory controller to write a word with
*data width*, the memory controller calculates the *syndrome* in real time,
@@ -212,7 +212,7 @@ EDAC - Error Detection And Correction
purposes.
When the subsystem was pushed upstream for the first time, on
- Kernel 2.6.16, for the first time, it was renamed to ``EDAC``.
+ Kernel 2.6.16, it was renamed to ``EDAC``.
Purpose
-------
@@ -351,15 +351,17 @@ controllers. The following example will assume 2 channels:
+------------+-----------+-----------+
| | ``ch0`` | ``ch1`` |
+============+===========+===========+
- | ``csrow0`` | DIMM_A0 | DIMM_B0 |
- | | rank0 | rank0 |
- +------------+ - | - |
+ | |**DIMM_A0**|**DIMM_B0**|
+ +------------+-----------+-----------+
+ | ``csrow0`` | rank0 | rank0 |
+ +------------+-----------+-----------+
| ``csrow1`` | rank1 | rank1 |
+------------+-----------+-----------+
- | ``csrow2`` | DIMM_A1 | DIMM_B1 |
- | | rank0 | rank0 |
- +------------+ - | - |
- | ``csrow3`` | rank1 | rank1 |
+ | |**DIMM_A1**|**DIMM_B1**|
+ +------------+-----------+-----------+
+ | ``csrow2`` | rank0 | rank0 |
+ +------------+-----------+-----------+
+ | ``csrow3`` | rank1 | rank1 |
+------------+-----------+-----------+
In the above example, there are 4 physical slots on the motherboard