kernbench2/tests/test_intercube_sfr_config.py

"""Tests for configure_sfr_intercube_multisip neighbor table wiring.

Verifies full IPCQ hardware wiring (independent of DPPolicy):
  - intra-cube (2×4 PE grid)  → intra_N/S/E/W
  - intercube same-lane       → N/S/E/W
  - inter-SIP same-(cube, pe) → global_N/S/E/W
"""
from __future__ import annotations

from pathlib import Path

from kernbench.ccl.install import load_ccl_config, resolve_algorithm_config
from kernbench.ccl.sfr_config import configure_sfr_intercube_multisip
from kernbench.sim_engine.engine import GraphEngine
from kernbench.topology.builder import resolve_topology

TOPOLOGY_PATH = Path(__file__).parent.parent / "topology.yaml"

N_CUBES = 16
PES_PER_CUBE = 8


def _engine_and_spec():
    topo = resolve_topology(str(TOPOLOGY_PATH))
    engine = GraphEngine(topo.topology_obj, enable_data=True)
    return engine, topo.topology_obj.spec


def _merged_cfg():
    cfg = load_ccl_config()
    return resolve_algorithm_config(cfg, name="intercube_allreduce")


class TestConfigureSfrNeighborTables:
    def test_world_size_and_rank_to_pe(self):
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        plan = configure_sfr_intercube_multisip(engine, spec, cfg)

        n_sips = int(spec["system"]["sips"]["count"])
        expected = n_sips * N_CUBES * PES_PER_CUBE
        assert plan["world_size"] == expected
        assert len(plan["rank_to_pe"]) == expected

    # ── Intra-cube (intra_N/S/E/W) ────────────────────────────────

    def test_pe0_intra_cube_has_intra_E_and_intra_S(self):
        """pe0 is NW of the 2×4 PE grid: intra_E=pe1, intra_S=pe4."""
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        qp = engine._components["sip0.cube0.pe0.pe_ipcq"].queue_pairs
        assert "intra_E" in qp
        assert qp["intra_E"]["peer"].pe == 1
        assert "intra_S" in qp
        assert qp["intra_S"]["peer"].pe == 4
        assert "intra_W" not in qp
        assert "intra_N" not in qp

    def test_pe5_intra_cube_has_all_four(self):
        """pe5 (row=1, col=1 in 2×4 grid) has all 4 intra directions.

        Intra neighbors: intra_N=pe1, intra_E=pe6, intra_W=pe4,
        intra_S not present (row=1 is bottom row).
        """
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        qp = engine._components["sip0.cube0.pe5.pe_ipcq"].queue_pairs
        assert qp["intra_N"]["peer"].pe == 1
        assert qp["intra_E"]["peer"].pe == 6
        assert qp["intra_W"]["peer"].pe == 4
        assert "intra_S" not in qp  # bottom row

    # ── Intercube same-lane (N/S/E/W) ─────────────────────────────

    def test_corner_cube0_pe0_has_intercube_E_and_S(self):
        """Cube 0 (NW mesh corner): intercube E→cube1, S→cube4."""
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        qp = engine._components["sip0.cube0.pe0.pe_ipcq"].queue_pairs
        assert qp["E"]["peer"].cube == 1
        assert qp["E"]["peer"].pe == 0  # same-lane
        assert qp["S"]["peer"].cube == 4
        assert qp["S"]["peer"].pe == 0
        assert "W" not in qp, "cube 0 has no west neighbor"
        assert "N" not in qp, "cube 0 has no north neighbor"

    def test_interior_cube5_pe3_has_all_four_intercube_same_lane(self):
        """Cube 5 interior, pe3: intercube N/S/E/W all present, same-lane."""
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        qp = engine._components["sip0.cube5.pe3.pe_ipcq"].queue_pairs
        for d, expected_cube in [("N", 1), ("S", 9), ("E", 6), ("W", 4)]:
            assert qp[d]["peer"].cube == expected_cube
            assert qp[d]["peer"].pe == 3  # same-lane

    def test_all_pes_have_intercube_wiring(self):
        """Every PE on every interior cube has intercube same-lane wiring."""
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        # Interior cube 5: every PE should have N/S/E/W same-lane.
        for pe in range(PES_PER_CUBE):
            qp = engine._components[f"sip0.cube5.pe{pe}.pe_ipcq"].queue_pairs
            for d in ("N", "S", "E", "W"):
                assert d in qp, f"sip0.cube5.pe{pe} missing intercube {d}"
                assert qp[d]["peer"].pe == pe, (
                    f"sip0.cube5.pe{pe} {d} not same-lane"
                )

    # ── Inter-SIP (global_*) ──────────────────────────────────────

    def test_every_pe_on_every_cube_has_inter_sip(self):
        """All PEs on all cubes wired for inter-SIP via global_*."""
        engine, spec = _engine_and_spec()
        cfg = _merged_cfg()
        configure_sfr_intercube_multisip(engine, spec, cfg)

        for cube_id in range(N_CUBES):
            for pe in range(PES_PER_CUBE):
                qp = engine._components[
                    f"sip0.cube{cube_id}.pe{pe}.pe_ipcq"
                ].queue_pairs
                assert "global_E" in qp, (
                    f"sip0.cube{cube_id}.pe{pe} missing global_E"
                )
                assert "global_W" in qp
                # Peer must be same (cube, pe) on another SIP.
                assert qp["global_E"]["peer"].sip == 1
                assert qp["global_E"]["peer"].cube == cube_id
                assert qp["global_E"]["peer"].pe == pe