Re: Testing RAM from userspace / question about memmap= arguments

[David Newall <david@davidnewall.com>]

Pavel Machek wrote:
> memtest has following problems:
>
> 	0) it is kind of hard to run memtest over ssh
>   

It's kind of hard to run anything over SSH if it has to be run before 
userspace is up.  But the kernel can collect results from a modified 
memtest, after it chains back.

> 	1) if linux fixes some problem with PCI quirk or microcode
> 	upload, memtest will not see the fix
>   

What are you saying?  Linux is going to fix faulty RAM?  The point with 
testing RAM is you *want* to see it fail; you don't want Linux to fix it.

> 	2) if memory only fails while something else happens (DMA to
> 	other piece of memory? Hard disk load glitching powre
> 	supply?), memtest will not see the problem.

These are not RAM faults.  The very last thing you want is evidence that 
you've got a faulty piece of RAM when the fault is actually a hard disk 
glitch!