| Message ID | 20140624010833.GF4323@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
Hi David, On 23.06.2014 [18:08:33 -0700], Nishanth Aravamudan wrote: > With generic sparse NUMA node parsing in place ("numa: enable sparse > node numbering"), ppc can be updated to iterate over only the > user-specified nodes. > > qemu-system-ppc64 -machine pseries,accel=kvm,usb=off -m 4096 > -realtime mlock=off -numa node,nodeid=3 -numa node,nodeid=2 -smp 4 I'd like to do so something similar for x86 as a follow-on patch, but I don't really know what the SRAT should look like, or what the APIC mapping should be to have sparse NUMA numbering? Some cursory googling indicates you've run into this in practice? Possibly with a bad APIC? Thanks, Nish
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 82f183f..d07857a 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -707,7 +707,10 @@ static int spapr_populate_memory(sPAPREnvironment *spapr, void *fdt) /* RAM: Node 1 and beyond */ mem_start = node0_size; - for (i = 1; i < nb_numa_nodes; i++) { + for (i = 1; i < max_numa_node; i++) { + if (!numa_info[i].present) { + continue; + } mem_reg_property[0] = cpu_to_be64(mem_start); if (mem_start >= ram_size) { node_size = 0;
With generic sparse NUMA node parsing in place ("numa: enable sparse node numbering"), ppc can be updated to iterate over only the user-specified nodes. qemu-system-ppc64 -machine pseries,accel=kvm,usb=off -m 4096 -realtime mlock=off -numa node,nodeid=3 -numa node,nodeid=2 -smp 4 Before: info numa: node 0 cpus: 0 2 node 0 size: 2048 MB node 1 cpus: 1 3 node 1 size: 2048 MB numactl --hardware: available: 2 nodes (0-1) node 0 cpus: 0 2 node 0 size: 2027 MB node 0 free: 1875 MB node 1 cpus: 1 3 node 1 size: 2045 MB node 1 free: 1980 MB node distances: node 0 1 0: 10 40 1: 40 10 After: info numa: node 2 cpus: 0 2 node 2 size: 2048 MB node 3 cpus: 1 3 node 3 size: 2048 MB numactl --hardware: available: 3 nodes (0,2-3) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 2 cpus: 0 2 node 2 size: 2027 MB node 2 free: 1943 MB node 3 cpus: 1 3 node 3 size: 2045 MB node 3 free: 1904 MB node distances: node 0 2 3 0: 10 40 40 2: 40 10 40 3: 40 40 10 Note, the empty node 0 is due to the Linux kernel. Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>