Fix closest-CPU-NUMA detection regression for GPU executors

[nileshnegi]

Motivation

Restore the Linux-NUMA-indexed cpuAgents[] table that the GPU-to-closest-CPU lookup in CollectTopology() depends on.

Technical Details

After #303, CPU agents were enumerated via hsa_iterate_agents + HSA_AGENT_INFO_NODE and stored at the HSA/KFD topology node id, which is not guaranteed to equal the Linux NUMA index (e.g., on systems where GPU agents are enumerated before CPU agents in the KFD topology). When the two diverged, cpuAgents[i] stayed default-initialized, the closestCpuAgent lookup never matched, and GetClosestCpuNumaToGpu() returned -1 for every GPU. That broke the topology display (all GPUs reported "no closest NUMA") and produced malformed transfer descriptors like "R0C-1" in any preset that consumes the result.

Switch back to the allocation-based enumeration that preserves cpuAgents[i] == "agent owning Linux NUMA i" while still tolerating NUMA nodes restricted by the process's cpuset / mempolicy: AllocateMemory(MEM_CPU) already rejects such nodes since #303, so we skip them on ERR_FATAL and leave the slot zero-initialized. Restricted NUMAs cannot service transfers anyway, so a zero-handle entry is the correct sentinel and harmless to the handle comparison performed by the closest-CPU lookup.

Also, drop the explicit hsa_init() / hsa_shut_down() around the iteration: HIP already manages HSA lifetime for this process, and tearing it down between topology collection and the rest of the run is unnecessary.

Test Plan

Test Result

Verified on 8 x gfx950, 2 NUMA nodes:

• ./TransferBench now prints the expected "NUMA 00 -> GPUs 0 1 2 3" / "NUMA 01 -> GPUs 4 5 6 7" mapping that pre-Fixing NUMA checks (set_mempolicy) #303 (e8edacf) produced.

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

[Copilot]

Pull request overview

Restores the pre-#303 behavior where cpuAgents[i] is indexed by Linux NUMA node, fixing a regression where GPU-to-closest-CPU lookups returned -1 because HSA/KFD node ids did not always match Linux NUMA indices.

Changes:

• Replace hsa_iterate_agents + HSA_AGENT_INFO_NODE enumeration with allocation-based discovery using AllocateMemory({MEM_CPU, i}, ...) and hsa_amd_pointer_info::agentOwner.
• Skip NUMA nodes restricted by cpuset/mempolicy (leaving zero-initialized sentinel) instead of aborting.
• Drop explicit hsa_init()/hsa_shut_down() around the iteration since HIP manages HSA lifetime.

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[nileshnegi]

Fixed in #305