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

[Peter Maydell]

On Wed, 12 Apr 2023 at 02:08, Gavin Shan <gshan@redhat.com> wrote:
>
> Hi Peter,
>
> On 3/27/23 9:26 PM, Igor Mammedov wrote:
> > 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>
> >
>
> Not sure if QEMU v8.0 is still available to integrate this series.
> Otherwise, it should be something for QEMU v8.1. By the way, I'm
> also uncertain who needs to be merge this series.

It barely touches arm specific boards, so I'm assuming it will
be reviewed and taken by whoever handles hw/core/machine.c

And yes, 8.0 is nearly out the door, this is 8.1 stuff.

thanks
-- PMM