Translating physical/linear address to virtual address

[ruben@mrbrklyn.com (Ruben Safir)]

On 10/03/2015 12:04 AM, Martin Ichilevici de Oliveira wrote:
> My goal is to use this data to make informed decisions on pages
> distribution in NUMA machines (with libnuma). The problem is that, as
> far as I understood, physical and linear addresses won't necessarily be
> the same between runs of the same program. Virtual addresses, on the
> other hand, can be made to be consistent (by turning address space layout
> randomization off).
> 
> Using virtual addresses also have the advantage that I can do all memory
> management in userspace, with libnuma.


Your not really understanding some basic architectural problems.  Memory
is shifted from segment to segment, the OS has paging, the hardware
hides memory addressing as well, and then there is DME.  How the
motherboard chips lays out and allows access to memory segments is not
something that can be manually controlled, even by the OS because it is
firmware driven.

I'm not saying that what you are doing is impossible, but it doesn't
sound like you approach is likely to work.


http://www.nylxs.com/docs/grad_school/arch/memory.pdf

http://www.nylxs.com/docs/grad_school/arch/