Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware
From: Michal Hocko <mhocko@kernel.org>
Date: 2019-09-24 11:54:07
Also in:
linux-alpha, linux-mips, linux-s390, linux-sh, lkml, sparclinux
On Tue 24-09-19 13:23:49, Peter Zijlstra wrote:
On Tue, Sep 24, 2019 at 12:56:22PM +0200, Michal Hocko wrote:
[...]
quoted
To be honest I really fail to see why to object to a simple semantic that NUMA_NO_NODE imply all usable cpus. Could you explain that please?Because it feels wrong. The device needs to be _somewhere_. It simply cannot be node-less.
What if it doesn't have any numa preference for what ever reason? There is no other way to express that than NUMA_NO_NODE. Anyway, I am not going to argue more about this because it seems more of a discussion about "HW shouldn't be doing that although the specification allows that" which cannot really have any outcome except of "feels correct/wrong". If you really feel strongly about this then we should think of a proper way to prevent this to happen because an out-of-bound access is certainly not something we really want, right? -- Michal Hocko SUSE Labs