Re: Optimizing memory access with DPDK allocated memory

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 20 May 2022 10:34:46 +0200
Antonio Di Bacco <a.dibacco.ks@gmail.com> wrote:

> Let us say I have two memory channels each one with its own 16GB memory
> module, I suppose the first memory channel will be used when addressing
> physical memory in the range 0 to 0x4 0000 0000 and the second when
> addressing physical memory in the range 0x4 0000 0000 to  0x7 ffff ffff.
> Correct?
> Now, I need to have a 2GB buffer with one "writer" and one "reader", the
> writer writes on half of the buffer (call it A) and, in the meantime, the
> reader reads on the other half (B). When the writer finishes writing its
> half buffer (A), signal it to the reader and they swap,  the reader starts
> to read from A and writer starts to write to B.
> If I allocate the whole buffer (on two 1GB hugepages) across the two memory
> channels, one half of the buffer is allocated on the end of first channel
> while the other half is allocated on the start of the second memory
> channel, would this increase performances compared to the whole buffer
> allocated within the same memory channel?

Most systems just interleave memory chips based on number of filled slots.
This is handled by BIOS before kernel even starts.
The DPDK has a number of memory channels parameter and what it does
is try and optimize memory allocation by spreading.

Looks like you are inventing your own limited version of what memif does.