Re: [PATCH] mm/mempolicy: add sysfs interface to override NUMA node bandwidth

From: Yee Li

Date: Thu Mar 12 2026 - 23:40:00 EST


Hi Joshua,

Thanks for your feedback and kind wishes.

I just wanted to touch on this. Is this true? Weighted interleave already
exposes sysfs that lets the user set the weights they want. On one hand
I think it would be helpful for there to be a tool to see what the
effects of setting bandwidth information on a system could be, if it
had other side effects. I'm not sure if there is a strong case to do this
purely for weighted interleave auto-tuning, which already has a manual
weight override and pretty simple calculations : -)

I agree — writing a small userspace tool to compute the weights based on
actual measured bandwidths (from mlc or stream) is a really good approach.

Thank you for the helpful clarification. Just to be sure, are there
other intended things that the user can test other than what weights
weighted interleave would resolve to?

We can continue DRAM + CXL weighted interleave performance testing later, following Gregory Price's experiments [1].
[1] Link:
https://lore.kernel.org/linux-mm/20240103224209.2541-1-gregory.price@xxxxxxxxxxxx/