Re: AMD EPYC 25 (19h): Hardware Error: Machine Check: 0 Bank 17: d42040000000011b

From: Paul Menzel
Date: Fri Apr 14 2023 - 05:26:37 EST


Dear Borislav,


Thank you for your quick and helpful reply.

Am 12.04.23 um 18:32 schrieb Borislav Petkov:
On Wed, Apr 12, 2023 at 05:11:26PM +0200, Paul Menzel wrote:
On a Dell PowerEdge R7525 with AMD EPYC 7763 64-Core Processor, Linux
5.15.94 logs the machine check exceptions (MCE) below:

```
[5154053.127240] mce: [Hardware Error]: Machine check events logged
[5154053.133711] mce: [Hardware Error]: CPU 3: Machine Check: 0 Bank 17: d42040000000011b
[5154053.141948] mce: [Hardware Error]: TSC 0 ADDR b3cbdbbc0 PPIN 2b615bef7f48098 SYND 6bd210000a801002 IPID 9600650f00

Build the latest kernel with CONFIG_X86_MCE_INJECT and
CONFIG_EDAC_DECODE_MCE enabled and CONFIG_RAS_CEC *disabled*. Then boot
it on that machine with and do the following below.

The files are in debugfs:

/sys/kernel/debug/mce-inject/
├── addr
├── bank
├── cpu
├── flags
├── ipid
├── misc
├── README
├── status
└── synd

so you go and do

echo 0xd42040000000011b > status
echo 0xb3cbdbbc0 > addr
echo 3 > cpu
echo "sw" > flags
echo 0x6bd210000a801002 > synd
echo 0x9600650f00 > ipid
echo 17 > bank

Remember to keep the bank write last because this one injects the error.

It should dump the decoded error in dmesg.

Yes, that worked:

```
[ 436.584741] mce: [Hardware Error]: Machine check events logged
[ 436.590638] [Hardware Error]: Corrected error, no action required.
[ 436.596869] [Hardware Error]: CPU:3 (19:1:1) MC17_STATUS[Over|CE|-|AddrV|-|SyndV|CECC|-|-|-]: 0xd42040000000011b
[ 436.607083] [Hardware Error]: Error Addr: 0x0000000b3cbdbbc0
[ 436.612763] [Hardware Error]: IPID: 0x0000009600650f00, Syndrome: 0x6bd210000a801002
[ 436.620569] [Hardware Error]: Unified Memory Controller Ext. Error Code: 0, DRAM ECC error.
[ 436.628942] [Hardware Error]: cache level: L3/GEN, tx: GEN, mem-tx: RD
```

It says “no action required”, but out of the identical 14 servers with the same workload this is the only one having shown this errors three times.

Maybe the DIMM at bank 17 should just be replaced.

[…]


Kind regards,

Paul