On Fri, Aug 14, 2020 at 05:54:19PM -0300, Daniel Henrique Barboza wrote: > The ibm,max-associativity-domains is considering that only a single > associativity domain can exist in the same NUMA level. This is true > today because we do not support any type of NUMA distance user > customization, and all nodes are in the same distance to each other. > > To enhance NUMA distance support in the pSeries machine we need to > make this limit flexible. This patch rewrites the max-associativity > logic to consider that multiple associativity domains can co-exist > in the same NUMA level. We're using the legacy_numa() helper to > avoid leaking unneeded guest changes.
Hrm. I find the above a bit hard to understand. Having the limit be
one less than the number of nodes at every level except the last seems
kind of odd to me.
> Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
> ---
> hw/ppc/spapr.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 073a59c47d..b0c4b80a23 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -919,13 +919,20 @@ static void spapr_dt_rtas(SpaprMachineState *spapr,
> void *fdt)
> cpu_to_be32(SPAPR_MEMORY_BLOCK_SIZE & 0xffffffff),
> cpu_to_be32(ms->smp.max_cpus / ms->smp.threads),
> };
> - uint32_t maxdomain = cpu_to_be32(spapr->extra_numa_nodes > 1 ? 1 : 0);
> +
> + /* The maximum domains for a given NUMA level, supposing that every
> + * additional NUMA node belongs to the same domain (aside from the
> + * 4th level, where we must support all available NUMA domains), is
> + * total number of domains - 1. */
> + uint32_t total_nodes_number = ms->numa_state->num_nodes +
> + spapr->extra_numa_nodes;
> + uint32_t maxdomain = cpu_to_be32(total_nodes_number - 1);
> uint32_t maxdomains[] = {
> cpu_to_be32(4),
> maxdomain,
> maxdomain,
> maxdomain,
> - cpu_to_be32(ms->numa_state->num_nodes + spapr->extra_numa_nodes),
> + cpu_to_be32(total_nodes_number),
> };
>
> _FDT(rtas = fdt_add_subnode(fdt, 0, "rtas"));
> @@ -962,6 +969,13 @@ static void spapr_dt_rtas(SpaprMachineState *spapr, void
> *fdt)
> qemu_hypertas->str, qemu_hypertas->len));
> g_string_free(qemu_hypertas, TRUE);
>
> + if (spapr_machine_using_legacy_numa(spapr)) {
> + maxdomain = cpu_to_be32(spapr->extra_numa_nodes > 1 ? 1 : 0);
> + maxdomains[1] = maxdomain;
> + maxdomains[2] = maxdomain;
> + maxdomains[3] = maxdomain;
> + }
> +
> if (smc->pre_5_1_assoc_refpoints) {
> nr_refpoints = 2;
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature
