Re: [PATCH 2/2] RAS: Introduce the FRU Memory Poison Manager

[Yazen Ghannam <yazen.ghannam@amd.com>]

On 2/14/2024 4:06 AM, Borislav Petkov wrote:
> On Tue, Feb 13, 2024 at 09:35:16PM -0600, Yazen Ghannam wrote:
>> Memory errors are an expected occurrence on systems with high memory
>> density. Generally, errors within a small number of unique physical
>> locations is acceptable, based on manufacturer and/or admin policy.
>> During run time, memory with errors may be retired so it is no longer
>> used by the system. This is done in the kernel memory manager, and the
>> effect will remain until the system is restarted.
>>
>> If a memory location is consistently faulty, then the same run time
>> error handling may occur in the next reboot cycle. Running jobs may be
>> terminated due to previously known bad memory. This could be prevented
>> if information from the previous boot was not lost.
>>
>> Some add-in cards with driver-managed memory have on-board persistent
>> storage. Their driver may save memory error information to the
>> persistent storage during run time. The information may then be restored
>> after reset, and known bad memory may be retired before use. A running
>> log of bad memory locations is kept across multiple resets.
> 
> Too many "may"s above, please tone them down.
>

Will try :)
  
>> A similar solution is desirable for CPUs. However, this solution should
> 
> GPUs you mean?
>

I mean CPUs. GPUs would fall under the "add-in" card scenario.
  
>> leverage industry-standard components, as much as possible, rather than
>> a bespoke platform driver.
>>
>> Two components are needed: a record format and a persistent storage
>> interface.
>>
>> A UEFI CPER "FRU Memory Poison Section" is being proposed, along with a
>> "Memory Poison Descriptor", to use for this purpose. These new structures
>> are minimal, saving space on limited non-volatile memory, and extensible.
>>
>> CPER-aware persistent storage interfaces, like ACPI ERST and EFI Runtime
>> Variables, can be used. A new interface is not required.
> 
> I don't think stuff which is being proposed belongs here.
>

Do you mean this should be left out of the commit message?
  
>> Implement a new module to manage the record formats on persistent
>> storage. Use the requirements for an AMD MI300-based system to start.
>> Vendor- and platform-specific details can be abstracted later as needed.
> 
> This is a big diff so I'm splitting mails.
> 

Okay.

Thanks,
Yazen