Messages in this thread | | | Date | Fri, 21 Jul 2017 19:23:45 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH 3/3] ghes_edac: add platform check to enable ghes_edac |
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On Fri, Jul 21, 2017 at 02:01:31PM -0300, Mauro Carvalho Chehab wrote: > I see the value of having a threshold in BIOS, provided that it is > well documented, and whose value can be adjusted, if needed. > > One of the things I wanted to implement in ras-daemon were an > algorithm that would be doing such threshold in software.
We have that now in the kernel: drivers/ras/cec.c
We did it exactly for that purpose - not upsetting users unnecessarily.
> The thing with a BIOS threshold is that the user has no way to > audit the algorithm. So, when BIOS start reporting such errors, > it may be already too late: the systems may be in the verge of > losing data (or some data was already lost).
Not only that: thresholds depend on the DIMM types which means, BIOS must know what DIMM types are in there which I doubt. So exposing that to configuration instead of "deciding" for people would be better.
> That's critical on cluster systems with thousands of machines: > while the impact of disabling a cluster node to do some maintainance > is marginal, the impact of an uncorrected error on a single > machine may compromise weeks of expensive processing. > > That's why some users prefer to monitor every single corrected > error, and compare with the probability distribution they > know that the risk of uncorrected errors is acceptable.
Yap, you need to have stuff like that configurable - BIOS can't predict all possible use cases.
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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