Re: [PATCH 1/1] eal: add API to get CPU socket ID

On Mon, 14 Sep 2026 15:28:14 -0400
Randy L Tice [off-list ref] wrote:

Add rte_cpu_socket_id() so applications can map an OS logical CPU
ID to its NUMA socket without requiring an EAL lcore ID.

Existing public socket APIs depend on EAL lcore configuration or the
calling thread's EAL state. They do not cover code that needs to look
up topology by OS CPU ID, such as building socket memory policy.

Reuse the existing per-OS EAL CPU socket lookup internally, while
keeping the eal_cpu_socket_id() helper private to EAL.

Signed-off-by: Randy L Tice <redacted>
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New API's should be marked as experimental, so there is no ABI contract.
The return value of eal_cpu_socket_id() has no way with that signature
to return error. If given a bogus cpu, that code returns 0.

New functions in DPDK need to have a matching test. Somewhere in
the existing dpdk-test would be good.

There was a bigger patch series to give a full topology API to
deal with more complex chip arch; but it seems to have stalled.