Re: [PATCH] x86/platform/uv: Handle deconfigured sockets
From: Steve Wahl
Date: Mon Mar 16 2026 - 12:55:20 EST
On Tue, Mar 10, 2026 at 05:49:57PM -0500, Kyle Meyer wrote:
> When a socket is deconfigured, it's mapped to SOCK_EMPTY (0xffff). This
> causes a panic while allocating UV hub info structures.
>
> Fix this by using NUMA_NO_NODE, allowing UV hub info structures to be
> allocated on valid nodes.
>
> Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
Reviewed-by: Steve Wahl <steve.wahl@xxxxxxx>
> ---
> arch/x86/kernel/apic/x2apic_uv_x.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
> index 15209f220e1f..daf9853f7868 100644
> --- a/arch/x86/kernel/apic/x2apic_uv_x.c
> +++ b/arch/x86/kernel/apic/x2apic_uv_x.c
> @@ -1708,8 +1708,22 @@ static void __init uv_system_init_hub(void)
> struct uv_hub_info_s *new_hub;
>
> /* Allocate & fill new per hub info list */
> - new_hub = (bid == 0) ? &uv_hub_info_node0
> - : kzalloc_node(bytes, GFP_KERNEL, uv_blade_to_node(bid));
> + if (bid == 0) {
> + new_hub = &uv_hub_info_node0;
> + } else {
> + int nid;
> +
> + /*
> + * Deconfigured sockets are mapped to SOCK_EMPTY. Use
> + * NUMA_NO_NODE to allocate on a valid node.
> + */
> + nid = uv_blade_to_node(bid);
> + if (nid == (int)SOCK_EMPTY)
> + nid = NUMA_NO_NODE;
> +
> + new_hub = kzalloc_node(bytes, GFP_KERNEL, nid);
> + }
> +
> if (WARN_ON_ONCE(!new_hub)) {
> /* do not kfree() bid 0, which is statically allocated */
> while (--bid > 0)
> --
> 2.43.0
>
--
Steve Wahl, Hewlett Packard Enterprise