Replaces the unsourced 32 KB/layer placeholder in the analytical chart
with T*(N-1)/N where T = h_q * S_q * (d_head*2 + 8) ~ 2.1 KB
(per-PE (m, l, O) payload) and N is the participant count of the
reduce-only chain per stage. Cases 2/3/6 analytical bars now match
the simulator-measured numbers within ~10% (was 6-30x over).
Also:
- Bumps the measurement S_kv from 8 K to 64 K to verify Cases 1, 2, 3, 6
are genuinely S_kv-independent and Cases 4, 5 scale linearly.
- In-bar descriptor on the paired chart is now wrapped to fit the bar
width, black, no background box, and centered between the analytical
and measured bars so the label applies to both.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Filename cleanup so every long-ctx GQA artifact has a consistent
"gqa_long_ctx_6cases_*" prefix (or "gqa_decode_long_ctx_6cases_*"
for decode-only charts). Old "4cases" / mixed names retired.
Renames (long_ctx + figures, content unchanged):
gqa_hbm_budget.png -> gqa_long_ctx_6cases_hbm_budget.png
gqa_4cases_summary.png -> gqa_long_ctx_6cases_summary.png
gqa_4cases_memory_comm_analytical -> gqa_long_ctx_6cases_memory_comm_analytical.png
gqa_4cases_memory_comm_paired -> gqa_long_ctx_6cases_memory_comm_paired.png
gqa_kv_sharding_6cases_diagram -> gqa_long_ctx_6cases_kv_sharding_diagram.png
gqa_kv_sharding_6cases_table -> gqa_long_ctx_6cases_kv_sharding_table.png
gqa_3cases_measured_comm.json -> gqa_long_ctx_6cases_measured_comm.json
gqa_decode_long_ctx_4cases_*.png -> gqa_decode_long_ctx_6cases_*.png
(figures dir; long_ctx never had old)
New 4-chart 6-case set in long_ctx output dir (regenerated by
paper_plot_gqa_decode_long_ctx_4cases.py, which now reads all 6
sweep_decode.json panels — Cases 1-6 with the same colour scheme
used elsewhere: red = overflow per-PE HBM, grey = neutral, blue
= Pareto-best ★):
gqa_decode_long_ctx_6cases_latency.png
gqa_decode_long_ctx_6cases_memory.png
gqa_decode_long_ctx_6cases_parallelism.png
gqa_decode_long_ctx_6cases_traffic.png
Generator scripts updated to write the new filenames + handle the
two new d_head-TP variants (Cases 4, 5) in their per-PE memory and
active-PE-count helpers. Figure widths bumped 10 -> 12 in to fit 6
multi-line case labels.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two new long-ctx decode attention kernels for the d_head-TP sharding
variants the 6-case chart predicts:
· _gqa_attention_decode_long_ctx_cube_sp_pe_tp_dhead.py
Cube-SP × PE-TP-d_head (Case 4 in chart). Per cube holds
S_kv/C tokens of full d_head; per PE holds same tokens but
only d_head/P dims. Partial Q·Kᵀ scores reduced intra-cube
before softmax; outer (m,ℓ,O) merge two-phase (intra+inter).
· _gqa_attention_decode_long_ctx_cube_tp_dhead_pe_sp.py
Cube-TP-d_head × PE-SP (Case 5). Per cube holds full S_kv
with only d_head/C dims; per PE holds S_kv/P of those dims.
Partial scores reduced inter-cube (UCIe) before softmax.
Sweep dispatch (gqa_decode_long_ctx_4cases.py) extended with two
new panels so the milestone-1h-gqa sweep covers all 6 cases.
Smoke test scripts/verify_case4_dhead_tp.py runs Cases 4/5/6 at
S_kv=2K to validate the kernels load and execute end-to-end.
Plus the figure-generation toolchain that produced the committed
PNGs in the prior commit (dd3337f):
· paper_plot_gqa_4cases_summary.py - 3-panel summary +
2-panel (analytical / paired-measured) chart generator.
_plot_comm now takes mode="analytical" | "paired".
· paper_plot_gqa_kv_sharding_diagram.py - 6-case 2-D KV-tensor
diagram + companion comparison-table PNG.
· measure_gqa_decode_placement_comm.py - runs all 6 kernels at
S_kv=8K, sums actual IPCQ-copy bytes from engine.op_log,
scales partial-score AR ×128 to S_kv=1M, writes
gqa_3cases_measured_comm.json (committed).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
mukesh