Kernel Summit: Virtual Memory [LWN.net]

Kernel Summit: Virtual Memory

Posted Jul 20, 2004 9:01 UTC (Tue) by jmshh (guest, #8257)
Parent article: Kernel Summit: Virtual Memory

Is there any talk about the little brother of hotplug memory: ECC memory scrubbing? Most memory failures seem to be random bit flips. System lifetime could be extended seriously by fixing those before the next flip happens at the same address.

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Kernel Summit: Virtual Memory

Posted Jul 21, 2004 23:38 UTC (Wed) by brouhaha (guest, #1698) [Link]

ECC memory scrubbing is best done by the hardware. The AMD 760MP and 760MPX chip sets do this, as does the memory controller built into the Opteron and Athlon64. I'm not sure about scrubbing on Intel-based hardware (though the first system I ever used with ECC memory scrubbing was an Intel iAPX-432 system in the early 1980s).

If the hardware does not have scrubbing support, it can be done by a user level process with no special kernel support needed, but it will thrash the data cache. You should be able to scrub slowly enough that the overhead is minimal, while still maintaining the benefit of scrubbing.

Kernel Summit: Virtual Memory

Posted Jul 23, 2004 12:44 UTC (Fri) by chloe_zen (guest, #8258) [Link]

Scrubbing isn't as interesting to me as monitoring. The ecc module is little-known and seldom used, sadly.