Messages in this thread | | | From | Matthew Bloch <> | Subject | Re: Testing RAM from userspace / question about memmap= arguments | Date | Thu, 20 Dec 2007 14:17:10 +0000 |
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Jon Masters wrote: > On Tue, 2007-12-18 at 17:06 +0000, Matthew Bloch wrote: > >> I can see a few potential problems, but since my understanding of the >> low-level memory mapping is muddy at best, I won't speculate; I'd just >> appreciate any more expert views on whether this does work, or could be >> made to work. > > Yo, > > I don't think your testing approach is thorough enough. Clearly (knowing > your line of business - as a virtual machine provider), you want to do > pre-production testing as part of your provisioning. I would suggest > instead of using mlock() from userspace of simply writing a kernel > module that does this for every page of available memory.
Yes this is to improve the efficiency of server burn-ins. I would consider a kernel module, but I still wouldn't be able to test the memory in which the kernel is sitting, which is my problem. I'm not sure even a kernel module could reliably test the memory in which it is residing (memtest86+ relocates itself to do this). Also I don't see how userspace testing is any less thorough than doing it in the kernel; I just need a creative way of accessing every single page of memory.
I may do some experiments with the memmap args, some bad RAM and shuffling it between DIMM sockets when I have the time :)
-- Matthew
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