Re: [RFC PATCH] sched/fair: Make tg->load_avg per node

From: Peter Zijlstra
Date: Wed Apr 12 2023 - 08:08:20 EST


On Thu, Mar 30, 2023 at 01:45:57PM -0400, Daniel Jordan wrote:

> The topology of my machine is different from yours, but it's the biggest
> I have, and I'm assuming cpu count is more important than topology when
> reproducing the remote accesses. I also tried on

Core count definitely matters some, but the thing that really hurts is
the cross-node (and cross-cache, which for intel happens to be the same
set) atomics.

I suppose the thing to measure is where this cost rises most sharply on
the AMD platforms -- is that cross LLC or cross Node?

I mean, setting up the split at boot time is fairly straight forward and
we could equally well split at LLC.