ywkang
b8213d43a9
Restores per-PE HBM controller partitioning that was lost in
commit 5917b34 ("Replace xbar/bridge/single-NOC with explicit
router mesh"), which had over-consolidated the per-slice HBM CTRL
into a single cube-wide ``hbm_ctrl`` connected to every router —
the opposite of what ADR-0019 D1/D4 specifies.
Builder splits ``hbm_ctrl`` into 8 ``hbm_ctrl.pe{X}`` instances per
cube, each reachable ONLY through PE_X's attaching router via the
existing ``peX.hbm`` attach metadata from cube_mesh.yaml. Cube
aggregate BW now matches the spec (8 PEs × 8 PCs × 32 GB/s =
2048 GB/s) instead of collapsing to 256 GB/s.
AddressResolver decodes the target PE from the HBM PA's hbm_offset
(``offset // slice_size``) and returns ``hbm_ctrl.pe{X}``. PathRouter
uses the existing ``_adj_local`` adjacency for same-cube PE_DMA so
the cube's own UCIe port can no longer appear as a zero-distance
shortcut between routers — local PE_DMA now traverses the mesh,
restoring the ADR-0019 D4 worked example
``PE0.pe_dma → r0c0 → … → r1c4 → hbm_ctrl``.
Tests:
- New tests/test_per_pe_hbm_partition.py: 14 tests covering
topology shape, per-PE router exclusivity, PA resolution,
single-hop local path, cross-PE mesh traversal, and end-to-end
latency monotonicity. Probe CLI now reports
pe-local < pe-same-half < pe-cross-half (was uniform 141ns).
- Existing tests updated for new node ids and replaced two
assertions that locked in the wrong consolidation:
test_noc_mesh.test_hbm_connects_to_all_routers and
test_topology_compile.test_hbm_ctrl_connects_all_routers are
now per-PE exclusivity assertions; test_routing
.test_all_pe_hbm_equidistant becomes
test_cross_pe_hbm_distance_increases_with_mesh_hops.
- test_ipcq_buffer_kind_locations.test_hbm_pe_hop_charged_at_large_payload
threshold recalibrated 4000→1500 ns: the prior figure reflected
serialization on the over-consolidated single hbm_ctrl; per-PE
partitioning removes that artificial contention so the gap
shrinks to the genuine PE↔HBM-hop cost.
Full suite: 645 passed, 1 skipped.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
602 B
602 B
| 1 | buffer_kind | sip_topology | n_sips | n_elem | bytes_per_pe | latency_ns |
|---|---|---|---|---|---|---|
| 2 | hbm | torus_2d | 6 | 128 | 256 | 2120.0399999999754 |
| 3 | hbm | torus_2d | 6 | 1024 | 2048 | 2716.74499999995 |
| 4 | hbm | torus_2d | 6 | 8192 | 16384 | 7315.185000000081 |
| 5 | hbm | torus_2d | 6 | 32768 | 65536 | 23081.265000008738 |
| 6 | sram | torus_2d | 6 | 128 | 256 | 2060.0399999999754 |
| 7 | sram | torus_2d | 6 | 1024 | 2048 | 2908.74499999995 |
| 8 | sram | torus_2d | 6 | 8192 | 16384 | 9523.185000000081 |
| 9 | sram | torus_2d | 6 | 32768 | 65536 | 32201.265000008752 |
| 10 | tcm | torus_2d | 6 | 128 | 256 | 1964.0399999999754 |
| 11 | tcm | torus_2d | 6 | 1024 | 2048 | 2476.74499999995 |
| 12 | tcm | torus_2d | 6 | 8192 | 16384 | 6403.185000000081 |
| 13 | tcm | torus_2d | 6 | 32768 | 65536 | 19865.265000008738 |