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

[Pavel Machek <pavel@ucw.cz>]

On Sun 2007-12-23 07:06:58, David Newall wrote:
> 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.

memtest can be ran from userspace, that's the point.

>> 	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?

Yes, that's what CPU microcode update is for. And I want to test my
RAM with up-to-date microcode.

>> 	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!

No, it may be power supply leading to RAM problems. Yes, I want to
detect that.
								Pavel
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