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Re: [PATCH v4 1/3] numa: Validate cluster and NUMA node boundary if requ
From: |
Alistair Francis |
Subject: |
Re: [PATCH v4 1/3] numa: Validate cluster and NUMA node boundary if required |
Date: |
Tue, 21 Mar 2023 21:39:26 +1000 |
On Fri, Mar 17, 2023 at 4:29 PM Gavin Shan <gshan@redhat.com> wrote:
>
> For some architectures like ARM64, multiple CPUs in one cluster can be
> associated with different NUMA nodes, which is irregular configuration
> because we shouldn't have this in baremetal environment. The irregular
> configuration causes Linux guest to misbehave, as the following warning
> messages indicate.
>
> -smp 6,maxcpus=6,sockets=2,clusters=1,cores=3,threads=1 \
> -numa node,nodeid=0,cpus=0-1,memdev=ram0 \
> -numa node,nodeid=1,cpus=2-3,memdev=ram1 \
> -numa node,nodeid=2,cpus=4-5,memdev=ram2 \
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at kernel/sched/topology.c:2271
> build_sched_domains+0x284/0x910
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-268.el9.aarch64 #1
> pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : build_sched_domains+0x284/0x910
> lr : build_sched_domains+0x184/0x910
> sp : ffff80000804bd50
> x29: ffff80000804bd50 x28: 0000000000000002 x27: 0000000000000000
> x26: ffff800009cf9a80 x25: 0000000000000000 x24: ffff800009cbf840
> x23: ffff000080325000 x22: ffff0000005df800 x21: ffff80000a4ce508
> x20: 0000000000000000 x19: ffff000080324440 x18: 0000000000000014
> x17: 00000000388925c0 x16: 000000005386a066 x15: 000000009c10cc2e
> x14: 00000000000001c0 x13: 0000000000000001 x12: ffff00007fffb1a0
> x11: ffff00007fffb180 x10: ffff80000a4ce508 x9 : 0000000000000041
> x8 : ffff80000a4ce500 x7 : ffff80000a4cf920 x6 : 0000000000000001
> x5 : 0000000000000001 x4 : 0000000000000007 x3 : 0000000000000002
> x2 : 0000000000001000 x1 : ffff80000a4cf928 x0 : 0000000000000001
> Call trace:
> build_sched_domains+0x284/0x910
> sched_init_domains+0xac/0xe0
> sched_init_smp+0x48/0xc8
> kernel_init_freeable+0x140/0x1ac
> kernel_init+0x28/0x140
> ret_from_fork+0x10/0x20
>
> Improve the situation to warn when multiple CPUs in one cluster have
> been associated with different NUMA nodes. However, one NUMA node is
> allowed to be associated with different clusters.
>
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> Acked-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> hw/core/machine.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> include/hw/boards.h | 1 +
> 2 files changed, 43 insertions(+)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 45e3d24fdc..a2329f975d 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -1255,6 +1255,45 @@ static void machine_numa_finish_cpu_init(MachineState
> *machine)
> g_string_free(s, true);
> }
>
> +static void validate_cpu_cluster_to_numa_boundary(MachineState *ms)
> +{
> + MachineClass *mc = MACHINE_GET_CLASS(ms);
> + NumaState *state = ms->numa_state;
> + const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(ms);
> + const CPUArchId *cpus = possible_cpus->cpus;
> + int i, j;
> +
> + if (state->num_nodes <= 1 || possible_cpus->len <= 1) {
> + return;
> + }
> +
> + /*
> + * The Linux scheduling domain can't be parsed when the multiple CPUs
> + * in one cluster have been associated with different NUMA nodes.
> However,
> + * it's fine to associate one NUMA node with CPUs in different clusters.
> + */
> + for (i = 0; i < possible_cpus->len; i++) {
> + for (j = i + 1; j < possible_cpus->len; j++) {
> + if (cpus[i].props.has_socket_id &&
> + cpus[i].props.has_cluster_id &&
> + cpus[i].props.has_node_id &&
> + cpus[j].props.has_socket_id &&
> + cpus[j].props.has_cluster_id &&
> + cpus[j].props.has_node_id &&
> + cpus[i].props.socket_id == cpus[j].props.socket_id &&
> + cpus[i].props.cluster_id == cpus[j].props.cluster_id &&
> + cpus[i].props.node_id != cpus[j].props.node_id) {
> + warn_report("CPU-%d and CPU-%d in socket-%ld-cluster-%ld "
> + "have been associated with node-%ld and
> node-%ld "
> + "respectively. It can cause OSes like Linux to "
> + "misbehave", i, j, cpus[i].props.socket_id,
> + cpus[i].props.cluster_id, cpus[i].props.node_id,
> + cpus[j].props.node_id);
> + }
> + }
> + }
> +}
> +
> MemoryRegion *machine_consume_memdev(MachineState *machine,
> HostMemoryBackend *backend)
> {
> @@ -1340,6 +1379,9 @@ void machine_run_board_init(MachineState *machine,
> const char *mem_path, Error *
> numa_complete_configuration(machine);
> if (machine->numa_state->num_nodes) {
> machine_numa_finish_cpu_init(machine);
> + if (machine_class->cpu_cluster_has_numa_boundary) {
> + validate_cpu_cluster_to_numa_boundary(machine);
> + }
> }
> }
>
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 6fbbfd56c8..c9793b2789 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -273,6 +273,7 @@ struct MachineClass {
> bool nvdimm_supported;
> bool numa_mem_supported;
> bool auto_enable_numa;
> + bool cpu_cluster_has_numa_boundary;
> SMPCompatProps smp_props;
> const char *default_ram_id;
>
> --
> 2.23.0
>
>