Messages in this thread | | | Date | Fri, 1 Nov 2002 14:14:59 -0500 (EST) | From | Ken Ryan <> | Subject | Re: [STATUS 2.5] October 30, 2002 |
| |
>Given that, "scrubbing" RAM seems to be somewhat useless on a >running system. The next write to the affected area will fix the >ECC bits, that't what is supposed to clear up the condition.
If a region of RAM isn't written to it won't help, and may accumulate additional errors. Kernel code, for instance, can then rot away. Scrubbing guarantees that all locations in memory get rewritten periodically, so correctable errors are removed.
I first saw this when I was brought in to help on a design for a spacecraft. Even rad-hard devices (these weren't) will flip a bit in a matter of hours due to background radiation. Non-hardened memories can get errors within minutes. Scrubbing assured the system would only notice once every few years (when too many bits get flipped in a word during the scrub interval).
Ken Ryan
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |