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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-25 18:07:36 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-25 18:07:36 -0800 |
commit | 9c91e6a5befb89d1494dd156dd4563f9e948a74f (patch) | |
tree | 8e3b4bf856d682c72b1b6c20f594a0763f044ddd /Documentation | |
parent | 752272f16dd18f2cac58a583a8673c8e2fb93abb (diff) | |
parent | 5781823fd0d39082bfe2bbc20408aaa85a6e06ad (diff) | |
download | lwn-9c91e6a5befb89d1494dd156dd4563f9e948a74f.tar.gz lwn-9c91e6a5befb89d1494dd156dd4563f9e948a74f.zip |
Merge tag 'edac_for_5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
Pull EDAC updates from Borislav Petkov:
"A lot of changes this time around, details below.
From the next cycle onwards, we'll switch the EDAC tree to topic
branches (instead of a single edac-for-next branch) which should make
the changes handling more flexible, hopefully. We'll see.
Summary:
- Rework error logging functions to accept a count of errors
parameter (Hanna Hawa)
- Part one of substantial EDAC core + ghes_edac driver cleanup
(Robert Richter)
- Print additional useful logging information in skx_* (Tony Luck)
- Improve amd64_edac hw detection + cleanups (Yazen Ghannam)
- Misc cleanups, fixes and code improvements"
* tag 'edac_for_5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: (35 commits)
EDAC/altera: Use the Altera System Manager driver
EDAC/altera: Cleanup the ECC Manager
EDAC/altera: Use fast register IO for S10 IRQs
EDAC/ghes: Do not warn when incrementing refcount on 0
EDAC/Documentation: Describe CPER module definition and DIMM ranks
EDAC: Unify the mc_event tracepoint call
EDAC/ghes: Remove intermediate buffer pvt->detail_location
EDAC/ghes: Fix grain calculation
EDAC/ghes: Use standard kernel macros for page calculations
EDAC: Remove misleading comment in struct edac_raw_error_desc
EDAC/mc: Reduce indentation level in edac_mc_handle_error()
EDAC/mc: Remove needless zero string termination
EDAC/mc: Do not BUG_ON() in edac_mc_alloc()
EDAC: Introduce an mci_for_each_dimm() iterator
EDAC: Remove EDAC_DIMM_OFF() macro
EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function
EDAC/amd64: Get rid of the ECC disabled long message
EDAC/ghes: Fix locking and memory barrier issues
EDAC/amd64: Check for memory before fully initializing an instance
EDAC/amd64: Use cached data when checking for ECC
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/admin-guide/ras.rst | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst index 2b20f5f7380d..0310db624964 100644 --- a/Documentation/admin-guide/ras.rst +++ b/Documentation/admin-guide/ras.rst @@ -330,9 +330,12 @@ There can be multiple csrows and multiple channels. .. [#f4] Nowadays, the term DIMM (Dual In-line Memory Module) is widely used to refer to a memory module, although there are other memory - packaging alternatives, like SO-DIMM, SIMM, etc. Along this document, - and inside the EDAC system, the term "dimm" is used for all memory - modules, even when they use a different kind of packaging. + packaging alternatives, like SO-DIMM, SIMM, etc. The UEFI + specification (Version 2.7) defines a memory module in the Common + Platform Error Record (CPER) section to be an SMBIOS Memory Device + (Type 17). Along this document, and inside the EDAC subsystem, the term + "dimm" is used for all memory modules, even when they use a + different kind of packaging. Memory controllers allow for several csrows, with 8 csrows being a typical value. Yet, the actual number of csrows depends on the layout of @@ -349,12 +352,14 @@ controllers. The following example will assume 2 channels: | | ``ch0`` | ``ch1`` | +============+===========+===========+ | ``csrow0`` | DIMM_A0 | DIMM_B0 | - +------------+ | | - | ``csrow1`` | | | + | | rank0 | rank0 | + +------------+ - | - | + | ``csrow1`` | rank1 | rank1 | +------------+-----------+-----------+ | ``csrow2`` | DIMM_A1 | DIMM_B1 | - +------------+ | | - | ``csrow3`` | | | + | | rank0 | rank0 | + +------------+ - | - | + | ``csrow3`` | rank1 | rank1 | +------------+-----------+-----------+ In the above example, there are 4 physical slots on the motherboard @@ -374,11 +379,13 @@ which the memory DIMM is placed. Thus, when 1 DIMM is placed in each Channel, the csrows cross both DIMMs. Memory DIMMs come single or dual "ranked". A rank is a populated csrow. -Thus, 2 single ranked DIMMs, placed in slots DIMM_A0 and DIMM_B0 above -will have just one csrow (csrow0). csrow1 will be empty. On the other -hand, when 2 dual ranked DIMMs are similarly placed, then both csrow0 -and csrow1 will be populated. The pattern repeats itself for csrow2 and -csrow3. +In the example above 2 dual ranked DIMMs are similarly placed. Thus, +both csrow0 and csrow1 are populated. On the other hand, when 2 single +ranked DIMMs are placed in slots DIMM_A0 and DIMM_B0, then they will +have just one csrow (csrow0) and csrow1 will be empty. The pattern +repeats itself for csrow2 and csrow3. Also note that some memory +controllers don't have any logic to identify the memory module, see +``rankX`` directories below. The representation of the above is reflected in the directory tree in EDAC's sysfs interface. Starting in directory |