Messages in this thread |  | | Date | Thu, 14 Nov 1996 16:46:28 -0800 | From | Steve VanDevender <> | Subject | Re: Linux & ECC memory |
| |
Kenneth Albanowski writes: > On Thu, 14 Nov 1996, Richard B. Johnson wrote: > > > ECC is handled in HARDWARE. It has to be. The idea is try to fix bad > > memory fetches rather than just executing the NMI which would declare > > that the system is broken then halt. I have not looked at the Linux NMI > > code, but with many errors of RAM using ECC, the NMI would not be executed > > because the bad fetch would be corrected. > > This is what I'm curious about. Does Linux's NMI code attempt to work > around some memory problems, or does it just panic? Also, can the glue > report successful error-correction, as well as failed error-correction? > (Or is it not useful to know if your memory has/had an error that was > correctable?)
It's necessary to have access to the additional bits used for ECC in order to attempt correction in software. I don't know of any systems that let you have access to the parity bit on a byte at the software level. ECC needs at least three extra bits per word to correct single-bit and detect double-bit errors.
> -- > Kenneth Albanowski (kjahds@kjahds.com, CIS: 70705,126)
|  |