[PATCH v3] vmcoreinfo: Track and log recoverable hardware errors

[Breno Leitao]

Hello Mauro,

On Wed, Jul 30, 2025 at 06:21:37PM +0200, Mauro Carvalho Chehab wrote:
> Em Wed, 30 Jul 2025 06:11:52 -0700
> Breno Leitao <leitao at debian.org> escreveu:
> > On Wed, Jul 30, 2025 at 10:13:13AM +0800, Shuai Xue wrote:
> > > In ghes_log_hwerr(), you're counting both CPER_SEV_CORRECTED and
> > > CPER_SEV_RECOVERABLE errors:  
> > 
> > Thanks. I was reading this code a bit more, and I want to make sure my
> > understanding is correct, giving I was confused about CORRECTED and
> > RECOVERABLE errors.
> > 
> > CPER_SEV_CORRECTED means it is corrected in the background, and the OS
> > was not even notified about it. That includes 1-bit ECC error.
> > THose are not the errors we are interested in, since they are irrelavant
> > to the OS.
> 
> Hardware-corrected errors aren't irrelevant. The rasdaemon utils capture
> such errors, as they may be a symptom of a hardware defect. In a matter
> of fact, at rasdamon, thresholds can be set to trigger an action, like
> for instance, disable memory blocks that contain defective memories.

Sorry, I meant that Hardware-corrected errors aren't relevant in the
context of this patch, where we are errors that the OS has some
influence and decision.

> This is specially relevant on HPC and supercomputer workloads, where
> it is a lot cheaper to disable a block of bad memory than to lose
> an entire job because that could take several weeks of run time on
> a supercomputer, just because a defective memory ended causing a
> failure at the application.

Agree. These errors are used in several ways, including to detect
hardware aging and hardware replacement at maintenance windows.

In this patchset, I am more focused on what information to add to
crashdump, so, it makes it easy to correlate crashes to hardware events,
and RECOVERABLE are the main ones.