Messages in this thread | | | Date | Thu, 10 Jun 2010 13:14:57 -0600 | Subject | Re: Aerospace and linux | From | Brian Gordon <> |
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Thank you both. This has been very helpful for me.
I think I read two conclusions: 1) R/O is a small percentage of RAM 2) To cover this small precentage would be non-trivial
Thank you both very much for your time and knowledge, I'll move along now.
On Thu, Jun 10, 2010 at 12:46 PM, Chris Friesen <cfriesen@nortel.com> wrote: > On 06/10/2010 12:38 PM, Brian Gordon wrote: > >> On the more exotic end, I have also seen systems that have dual >> redundant processors / memories. Then they add compare logic between >> the redundant processors that compare most pins each clock cycle. If >> any pins are not identical at a clock cycle, then something has gone >> wrong (SEU, hardware failure, etc..) > > Some phone switches do this. Some of them also have at least two copies > of everything in memory and will do transactional operations that can be > rolled back if there is a hardware glitch. > >> So, some pages of RAM are going to be read-only and the data in those >> pages came from some source (file system?). Can anyone describe a >> high level strategy to occasionaly provide some coverage of this data? > >> So far I have thought about page descriptors adding an MD5 hash >> whenever they are read-only and first being "loaded/mapped?" and then >> a background daemon could occasionaly verify. > > Makes sense to me. You might also pick an on-disk format with extra > checksumming so you could compare the on-disk checksum with the > in-memory checksum. > > Chris > > -- > The author works for GENBAND Corporation (GENBAND) who is solely > responsible for this email and its contents. All enquiries regarding > this email should be addressed to GENBAND. Nortel has provided the use > of the nortel.com domain to GENBAND in connection with this email solely > for the purpose of connectivity and Nortel Networks Inc. has no > liability for the email or its contents. GENBAND's web site is > http://www.genband.com > -- 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/
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