On Wed, Mar 22, 2023 at 09:16:55AM -0700, Dave Hansen wrote: > On 3/21/23 09:40, Matthew Wilcox wrote: > > On Tue, Mar 21, 2023 at 09:30:59AM +0100, Geert Uytterhoeven wrote: > >> -#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP) > >> +#if defined(CONFIG_NUMA) || defined(CONFIG_SMP) > > I'm amused by the thought of CONFIG_NUMA without CONFIG_SMP. > > Is it possible to have one node with memory and a single CPU, then > > another node with memory and no CPU? > > It's _possible_ for sure, just unlikely. The most likely place these > days is probably a teensy tiny VM that just happens to have some > performance-differentiated memory exposed to it for some reason. Maybe > it's got a slice of slow PMEM or fast High-Bandwidth memory for whatever > reason. Right, you can construct such a system, but do we support the CONFIG options of NUMA enabled and SMP disabled? It seems so niche that we shouldn't be spending time testing that combination.
