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

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To: Pavel Machek <pavel@...>
Cc: Matthew Bloch <matthew@...>, <linux-kernel@...>
Date: Wednesday, December 26, 2007 - 6:17 am

On Wed, 26 Dec 2007 00:09:57 +0100
Pavel Machek wrote:

> On Sat 2007-12-22 12:09:59, Arjan van de Ven wrote:

> > memtest86+ does various magic to basically bypass the caches (by

that's... not nearly usable or enough. Caches are relatively smart
about things like use-once.... and they're huge. 12Mb today. You'd need
patterns bigger than 100Mb to get even close to being reasonably
confident that there's nothing left.

> ... and IIRC my celeron testing confirmed it, if

and a new syscall of some sorts I suspect; "flush all caches" is a ring
0 operation (and you probably need to do it in an ipi anyway on all
cpus)

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Re: Testing RAM from userspace / question about memmap= argu..., Arjan van de Ven, (Wed Dec 26, 6:17 am)