Re: [PATCH v4 0/3] NUMA: Apply cluster-NUMA-node boundary for aarch64 and riscv machines

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 17 Mar 2023 14:25:39 +0800
Gavin Shan <gshan@redhat.com> wrote:

> For arm64 and riscv architecture, the driver (/base/arch_topology.c) is
> used to populate the CPU topology in the Linux guest. It's required that
> the CPUs in one cluster can't span mutiple NUMA nodes. Otherwise, the Linux
> scheduling domain can't be sorted out, as the following warning message
> indicates. To avoid the unexpected confusion, this series attempts to
> warn about such kind of irregular configurations.
> 
>    -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
> 
> PATCH[1] Warn about the irregular configuration if required
> PATCH[2] Enable the validation for aarch64 machines
> PATCH[3] Enable the validation for riscv machines
> 
> v3: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg01226.html
> v2: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg01080.html
> v1: https://lists.nongnu.org/archive/html/qemu-arm/2023-02/msg00886.html
> 
> Changelog
> =========
> v4:
>   * Pick r-b and ack-b from Daniel/Philippe                   (Gavin)
>   * Replace local variable @len with possible_cpus->len in
>     validate_cpu_cluster_to_numa_boundary()                   (Philippe)
> v3:
>   * Validate cluster-to-NUMA instead of socket-to-NUMA
>     boundary                                                  (Gavin)
>   * Move the switch from MachineState to MachineClass         (Philippe)
>   * Warning instead of rejecting the irregular configuration  (Daniel)
>   * Comments to mention cluster-to-NUMA is platform instead
>     of architectural choice                                   (Drew)
>   * Drop PATCH[v2 1/4] related to qtests/numa-test            (Gavin)
> v2:
>   * Fix socket-NUMA-node boundary issues in qtests/numa-test  (Gavin)
>   * Add helper set_numa_socket_boundary() and validate the
>     boundary in the generic path                              (Philippe)
> 
> Gavin Shan (3):
>   numa: Validate cluster and NUMA node boundary if required
>   hw/arm: Validate cluster and NUMA node boundary
>   hw/riscv: Validate cluster and NUMA node boundary
> 
>  hw/arm/sbsa-ref.c   |  2 ++
>  hw/arm/virt.c       |  2 ++
>  hw/core/machine.c   | 42 ++++++++++++++++++++++++++++++++++++++++++
>  hw/riscv/spike.c    |  2 ++
>  hw/riscv/virt.c     |  2 ++
>  include/hw/boards.h |  1 +
>  6 files changed, 51 insertions(+)
> 

Acked-by: Igor Mammedov <imammedo@redhat.com>