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authorTomas Mudrunka <tomas.mudrunka@gmail.com>2023-03-21 11:34:30 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-04-05 19:42:55 -0700
commitbd23024b9774e681cbe6cc3afcb24244dfcb2390 (patch)
tree660d52ca5ef5b776a2299b5a189add72d34c39c9 /Documentation/filesystems/proc.rst
parentc9bb52738b39fabc8b6b9446f0d194eedb3e5a10 (diff)
downloadlwn-bd23024b9774e681cbe6cc3afcb24244dfcb2390.tar.gz
lwn-bd23024b9774e681cbe6cc3afcb24244dfcb2390.zip
mm/memtest: add results of early memtest to /proc/meminfo
Currently the memtest results were only presented in dmesg. When running a large fleet of devices without ECC RAM it's currently not easy to do bulk monitoring for memory corruption. You have to parse dmesg, but that's a ring buffer so the error might disappear after some time. In general I do not consider dmesg to be a great API to query RAM status. In several companies I've seen such errors remain undetected and cause issues for way too long. So I think it makes sense to provide a monitoring API, so that we can safely detect and act upon them. This adds /proc/meminfo entry which can be easily used by scripts. Link: https://lkml.kernel.org/r/20230321103430.7130-1-tomas.mudrunka@gmail.com Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems/proc.rst')
-rw-r--r--Documentation/filesystems/proc.rst8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 9d5fd9424e8b..8740362f31c6 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -996,6 +996,7 @@ Example output. You may not have all of these fields.
VmallocUsed: 40444 kB
VmallocChunk: 0 kB
Percpu: 29312 kB
+ EarlyMemtestBad: 0 kB
HardwareCorrupted: 0 kB
AnonHugePages: 4149248 kB
ShmemHugePages: 0 kB
@@ -1146,6 +1147,13 @@ VmallocChunk
Percpu
Memory allocated to the percpu allocator used to back percpu
allocations. This stat excludes the cost of metadata.
+EarlyMemtestBad
+ The amount of RAM/memory in kB, that was identified as corrupted
+ by early memtest. If memtest was not run, this field will not
+ be displayed at all. Size is never rounded down to 0 kB.
+ That means if 0 kB is reported, you can safely assume
+ there was at least one pass of memtest and none of the passes
+ found a single faulty byte of RAM.
HardwareCorrupted
The amount of RAM/memory in KB, the kernel identifies as
corrupted.