On Mon, Nov 12, 2018 at 08:54:12AM -0800, Daniel Jordan wrote: > On Sat, Nov 10, 2018 at 03:48:14AM +0000, Elliott, Robert (Persistent Memory) wrote: > > > -----Original Message----- > > > From: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel- > > > owner@xxxxxxxxxxxxxxx> On Behalf Of Daniel Jordan > > > Sent: Monday, November 05, 2018 10:56 AM > > > Subject: [RFC PATCH v4 11/13] mm: parallelize deferred struct page > > > initialization within each node > > > > > > ... The kernel doesn't > > > know the memory bandwidth of a given system to get the most efficient > > > number of threads, so there's some guesswork involved. > > > > The ACPI HMAT (Heterogeneous Memory Attribute Table) is designed to report > > that kind of information, and could facilitate automatic tuning. > > > > There was discussion last year about kernel support for it: > > https://lore.kernel.org/lkml/20171214021019.13579-1-ross.zwisler@xxxxxxxxxxxxxxx/ > > Thanks for bringing this up. I'm traveling but will take a closer look when I > get back. So this series would give the total bandwidth for a memory target, but there's not a way to map that to a CPU count. In other words, it seems we couldn't determine how many CPUs it takes to reach the max bandwidth. If I haven't missed something, I'm going to remove that comment.
