From ea089eebbd80e61d3c3cd03741dd5d9535c551fc Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 10 May 2017 13:29:45 +0200 Subject: numa: move source of default CPUs to NUMA node mapping into boards Originally CPU threads were by default assigned in round-robin fashion. However it was causing issues in guest since CPU threads from the same socket/core could be placed on different NUMA nodes. Commit fb43b73b (pc: fix default VCPU to NUMA node mapping) fixed it by grouping threads within a socket on the same node introducing cpu_index_to_socket_id() callback and commit 20bb648d (spapr: Fix default NUMA node allocation for threads) reused callback to fix similar issues for SPAPR machine even though socket doesn't make much sense there. As result QEMU ended up having 3 default distribution rules used by 3 targets /virt-arm, spapr, pc/. In effort of moving NUMA mapping for CPUs into possible_cpus, generalize default mapping in numa.c by making boards decide on default mapping and let them explicitly tell generic numa code to which node a CPU thread belongs to by replacing cpu_index_to_socket_id() with @cpu_index_to_instance_props() which provides default node_id assigned by board to specified cpu_index. Signed-off-by: Igor Mammedov Reviewed-by: Eduardo Habkost Message-Id: <1494415802-227633-2-git-send-email-imammedo@redhat.com> Reviewed-by: David Gibson Signed-off-by: Eduardo Habkost --- numa.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) (limited to 'numa.c') diff --git a/numa.c b/numa.c index d753687dec..bcdfca2309 100644 --- a/numa.c +++ b/numa.c @@ -443,9 +443,10 @@ void numa_default_auto_assign_ram(MachineClass *mc, NodeInfo *nodes, nodes[i].node_mem = size - usedmem; } -void parse_numa_opts(MachineClass *mc) +void parse_numa_opts(MachineState *ms) { int i; + MachineClass *mc = MACHINE_GET_CLASS(ms); for (i = 0; i < MAX_NODES; i++) { numa_info[i].node_cpu = bitmap_new(max_cpus); @@ -511,21 +512,18 @@ void parse_numa_opts(MachineClass *mc) break; } } - /* Historically VCPUs were assigned in round-robin order to NUMA - * nodes. However it causes issues with guest not handling it nice - * in case where cores/threads from a multicore CPU appear on - * different nodes. So allow boards to override default distribution - * rule grouping VCPUs by socket so that VCPUs from the same socket - * would be on the same node. - */ + + /* assign CPUs to nodes using board provided default mapping */ + if (!mc->cpu_index_to_instance_props) { + error_report("default CPUs to NUMA node mapping isn't supported"); + exit(1); + } if (i == nb_numa_nodes) { for (i = 0; i < max_cpus; i++) { - unsigned node_id = i % nb_numa_nodes; - if (mc->cpu_index_to_socket_id) { - node_id = mc->cpu_index_to_socket_id(i) % nb_numa_nodes; - } + CpuInstanceProperties props; + props = mc->cpu_index_to_instance_props(ms, i); - set_bit(i, numa_info[node_id].node_cpu); + set_bit(i, numa_info[props.node_id].node_cpu); } } -- cgit v1.2.3-55-g7522