Skip to content

Congestion-Aware Initial Accumulated Cost #3031

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Merged
merged 62 commits into from
Jun 20, 2025
Merged

Congestion-Aware Initial Accumulated Cost #3031

merged 62 commits into from
Jun 20, 2025

Conversation

soheilshahrouz
Copy link
Contributor

@soheilshahrouz soheilshahrouz commented May 10, 2025 •
edited
Loading

This PR adds a new option to bias routing away from congested channels during early iterations by adjusting the initial accumulated cost based on estimated CHANX/CHANY utilization.

@soheilshahrouz
enum class e_route_type
f76808d
@soheilshahrouz
add estimate_routing_chann_util()
a9435b4
@soheilshahrouz
add set_estimated_routing_util()
6a03592
@soheilshahrouz
add empty() to prefix sum class
823c1a0
@soheilshahrouz
const reference
3208425
@soheilshahrouz
add chan_util_threshold and congestion_weight arguments to set_estima…
f28832e 
…ted_routing_util()
@soheilshahrouz
implemented channel congestion factoring in map lookahead
b68b529
@soheilshahrouz
call set_estimated_routing_util() at the end of placement
93b1d03
@soheilshahrouz
add cmd line options for router lookahead congestion related params
177f73c
@soheilshahrouz
correct x_factor in congestion estimate of map lookahead
0c148d7
@soheilshahrouz
initialize acc_cost based on post-placement channel util estimate
21add30
@soheilshahrouz
initialize chan_util_weight and chan_util_threshold with some cmd lin…
30e0796 
…e options
@soheilshahrouz
init acc_cost with channel util info only if such info is availale
38e748f
@soheilshahrouz
Merge branch 'master' into temp_lookahead_chan_cong
808b2ef
@soheilshahrouz
document empty() method for prefix sum classes
133c3de
@soheilshahrouz
move t_rr_node_route_inf from vpr_types.h to rr_node_types.h
56e8ee5
@soheilshahrouz
add doxygen comment for NetCostHandler::estimate_routing_chann_util()
d6a8222
@soheilshahrouz
remove dead code in Placer::copy_locs_to_global_state()
dcf76f2
@soheilshahrouz
move chan_util_threshold and chan_util_weight from routing context to…
83813fa 
… t_route_opts

check if ExtendedMapLookahead fails
@soheilshahrouz
remove changes made to routerlookahead
3ca5542
@soheilshahrouz
make format
c36bfb9
@github-actions github-actions bot added VPR VPR FPGA Placement & Routing Tool lang-cpp C/C++ code libvtrutil labels May 10, 2025
@soheilshahrouz
Copy link
Contributor Author

soheilshahrouz commented May 11, 2025 •
edited
Loading

To-do list

  1. compute channel widths by iterating over RR nodes ---> done
  2. support 3d ---> CHANX/CHANY utilization for all layers are computed. CHANX nodes that represent vertical connection are mistakenly initilized with acc_cost of the CHANX at that location.

@soheilshahrouz
Copy link
Contributor Author

soheilshahrouz commented May 12, 2025 •
edited
Loading

titan_quick_qor

channel width place_time wl cpd route_time pack_time heap_pops total_swaps
300 1.0007 0.9991 0.9965 0.9993 0.9950 1.0067 1
270 1.0054 0.9984 1.0047 0.9615 0.9965 0.9914 1
250 0.9876 0.9981 1.0031 0.8403 0.9924 0.8510 1

In experiments with a channel width of 250, bitcoin_miner failed for both the master branch and this branch.

@soheilshahrouz
Copy link
Contributor Author

VTR benchmarks minimum channel width search

Metric feature.txt
vtr_flow_elapsed_time 1.109599868
odin_synth_time
parmys_synth_time 0.9942209611
abc_depth 1
abc_synth_time 1.001840561
num_clb 1
num_memories 1
num_mult 1
max_vpr_mem 0.9914816969
num_pre_packed_blocks 1
num_post_packed_blocks 1
device_grid_tiles 1
pack_time 1.000728945
placed_wirelength_est 1
place_time 1.025983213
placed_CPD_est 1
min_chan_width 0.9906351292
routed_wirelength 1.002237975
min_chan_width_route_time 1.352100907
crit_path_routed_wirelength 1.001354999
critical_path_delay 1.000111178
geomean_nonvirtual_intradomain_critical_path_delay 1.000111178
crit_path_route_time 0.9794380194

Minimum channel width was reduced in two circuits.

@soheilshahrouz
Copy link
Contributor Author

VTR benchmarks
1.3minW

circuit route_time cpd heap_pops wl place_time pack_time
mcml.v 0.9625 0.9999531016 1.019235354 1.000281936 0.9766849315 1.001701838
LU32PEEng.v 0.9503321734 1.000014647 0.990690786 1.00014595 0.9954708105 0.9987463762
bgm.v 0.9737302977 0.9996530479 0.997730871 1.000230386 1.023058997 1.002453988
LU8PEEng.v 1.014973262 1.000074797 1.00165337 0.9988697785 1.0022553 0.9980750722
arm_core.v 1 1.000592746 0.9855161027 0.9969095411 1.004594181 1.045816253
stereovision2.v 1.005747126 0.9996107903 1.000784028 0.9993899826 1.076231263 1
stereovision1.v 1.088560886 1.00187781 1.121788749 1.00002572 1.027617952 0.9646504321

@vaughnbetz
Copy link
Contributor

Looks good, thanks. We should get koios as well, since this is a big change.

@soheilshahrouz
Copy link
Contributor Author

soheilshahrouz commented Jun 1, 2025 •
edited
Loading

W=300

circuit CPD WL route_time heap_pops
tpu_like.small.os.v 1 1 1.015254237 1
tpu_like.small.ws.v 1 1 1.007668712 1
dla_like.small.v 1 0.999768608 1.018815717 1.004269293
bnn.v 1 0.9994662975 1.009292352 1.002568516
attention_layer.v 1 1 1.010739857 1
conv_layer_hls.v 1 1 0.9164619165 1
conv_layer.v 1 0.9993863978 1.053030303 1.00142193
eltwise_layer.v 1 0.9999351936 1.01025641 0.9879354833
robot_rl.v 1 1 0.9909090909 1
reduction_layer.v 1 1 0.9980430528 1
spmv.v 1 1 1.015789474 1
softmax.v 1 1 1.006349206 1
lenet.v 1.039334614 0.9979187016 1.005524862 0.9996246427
clstm_like.small.v 1 1 1.01551481 1
clstm_like.medium.v 0.9050457455 1.001017806 1.082175466 1.023845394
clstm_like.large.v 0.9523361003 1.000231865 0.974962828 0.9789848833
lstm.v 1 1 1.010317256 1
gemm_layer.v 0.8776401523 1.002186012 0.9898989899 1.013215695
tpu_like.large.os.v 1 1 1.0078075 1
tpu_like.large.ws.v 0.9912466445 0.9995306955 1.050833995 1.000956747
tdarknet_like.large.v 1 1 1.033892216 1
dla_like.medium.v 1 0.9998589942 1.004281637 0.994174936
bwave_like.float.small.v 1.020427253 1.000608795 0.9642172524 0.9816747451
bwave_like.fixed.small.v 1 1 1.013428827 1
dnnweaver.v 0.9881222569 1.001165979 0.9958448753 1.027681813
tdarknet_like.small.v 1 1 1.010583283 1
bwave_like.float.large.v 0.9734685948 1.001004839 0.9627392414 0.961273596
bwave_like.fixed.large.v 1 1.001696565 1.037675234 1.061526364
dla_like.large.v 0.9755507261 1.000620627 1.000162533 0.9959337593
proxy.1.v 1 0.9999891434 1.009653311 0.9993780357
proxy.2.v 1 1.000104018 0.9421366655 0.9980725353
proxy.3.v 1 1.000798333 0.9704296935 0.9980512289
proxy.4.v 1.009819358 1.000263529 1.012186732 1.009834591
proxy.5.v 1 1 0.9941634241 1
proxy.6.v 1 0.9998606597 1.00491763 1.00369854
proxy.7.v 1 1.000165903 1.00448682 1.013426537
proxy.8.v 1 0.9994262478 0.9944341373 0.9971751271
geomean 0.9927835526 1.000135276 1.003915663 1.001479038

@soheilshahrouz
Copy link
Contributor Author

vtr_reg_nightly_test7/3d_sb_titan_other_auto_bb

circuit CPD WL route_time heap_pops
carpat_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.03
CH_DFSIN_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
CHERI_stratixiv_arch_timing.blif 1.00 1.00 1.05 1.02
EKF-SLAM_Jacobians_stratixiv_arch_timing.blif 1.00 1.00 1.04 1.03
fir_cascade_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
jacobi_stratixiv_arch_timing.blif 1.00 1.00 1.07 1.12
JPEG_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.01
leon2_stratixiv_arch_timing.blif 1.00 1.00 0.96 0.93
leon3mp_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.01
MCML_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.00
MMM_stratixiv_arch_timing.blif 1.00 1.00 1.05 1.00
radar20_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
random_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
Reed_Solomon_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
smithwaterman_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
stap_steering_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
sudoku_check_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.01
SURF_desc_stratixiv_arch_timing.blif 1.00 1.00 0.98 1.01
ucsb_152_tap_fir_stratixiv_arch_timing.blif 1.00 1.00 1.04 1.00
uoft_raytracer_stratixiv_arch_timing.blif 1.00 1.00 1.03 1.04
wb_conmax_stratixiv_arch_timing.blif 1.00 1.00 0.99 1.00
picosoc_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.00
murax_stratixiv_arch_timing.blif 1.00 1.00 1.04 1.00
geomean 1.00 1.00 1.01 1.01

@soheilshahrouz
Copy link
Contributor Author

vtr_reg_nightly_test7/3d_cb_titan_other_auto_bb

circuit CPD WL route_time heap_pops
carpat_stratixiv_arch_timing.blif 1.00 1.00 1.00 0.99
CH_DFSIN_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
CHERI_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.01
EKF-SLAM_Jacobians_stratixiv_arch_timing.blif 1.00 1.00 1.11 1.15
fir_cascade_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.00
jacobi_stratixiv_arch_timing.blif 1.00 1.00 1.03 1.01
JPEG_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
leon2_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.01
leon3mp_stratixiv_arch_timing.blif 1.00 1.00 0.98 0.99
MCML_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
MMM_stratixiv_arch_timing.blif 1.00 1.00 1.02 0.99
radar20_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
random_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
Reed_Solomon_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
smithwaterman_stratixiv_arch_timing.blif 1.00 1.00 1.01 1.00
stap_steering_stratixiv_arch_timing.blif 1.00 1.00 0.99 1.00
sudoku_check_stratixiv_arch_timing.blif 1.00 1.00 1.00 0.99
SURF_desc_stratixiv_arch_timing.blif 1.00 1.00 1.04 1.03
ucsb_152_tap_fir_stratixiv_arch_timing.blif 1.00 1.00 1.00 1.00
uoft_raytracer_stratixiv_arch_timing.blif 1.00 1.00 0.99 1.01
wb_conmax_stratixiv_arch_timing.blif 1.00 1.00 0.98 1.00
picosoc_stratixiv_arch_timing.blif 1.00 1.00 0.99 1.00
murax_stratixiv_arch_timing.blif 1.00 1.00 1.02 1.00
geomean 1.00 1.00 1.01 1.01

@soheilshahrouz
Copy link
Contributor Author

vtr_reg_nightly_test7/vtr_reg_qor_large_run_flat

Metric feature.txt
vtr_flow_elapsed_time 1.043
odin_synth_time
parmys_synth_time 1.038
abc_depth 1
abc_synth_time 1.025
num_clb 1
num_memories 1
num_mult 1
max_vpr_mem 1.003
num_pre_packed_blocks 1
num_post_packed_blocks 1
device_grid_tiles 1
pack_time 1.005
placed_wirelength_est 1
place_time 1.024
placed_CPD_est 1
routed_wirelength 1.011
critical_path_delay 0.993
geomean_nonvirtual_intradomain_critical_path_delay 0.993
crit_path_route_time 1.049

@soheilshahrouz
Copy link
Contributor Author

@vaughnbetz
I added QoR for flat routing and 3D. This PR is ready to merge

@vaughnbetz
Copy link
Contributor

Please summarize where we see benefits, and take a look at the minimum channel width results (cpu time is up --> just the two circuits with better results?)

@soheilshahrouz
Copy link
Contributor Author

soheilshahrouz commented Jun 16, 2025 •
edited
Loading

Please summarize where we see benefits, and take a look at the minimum channel width results (cpu time is up --> just the two circuits with better results?)

The minimum channel width is reduced for both mcml and LU32PEEng. For LU32PEEng, this leads to an 8.6x increase in routing time at minimum channel width. mcml experiences only a minimum channel width route time increase of 1.07x. In both cases, the increased runtime can be attributed to more iterations in the binary search for the minimum channel width.

When the channel width is low enough to cause congestion, routing converges faster if the acc_cost of RR nodes in congested channels starts with a value larger than 1.

vaughnbetz
vaughnbetz approved these changes Jun 16, 2025
View reviewed changes
Copy link
Contributor

@vaughnbetz vaughnbetz left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Some testing for --route, and think about whether the state transfer from place->route would be cleaner if the router loaded everything.

AmirhosseinPoolad and others added 4 commits June 17, 2025 13:39
@AmirhosseinPoolad
Merge branch 'master' into temp_lookahead_chan_cong
23f7763
@soheilshahrouz
add RoutingChanUtilEstimator class
8349c44 
When the placement was read from a file, NetCostHandler was never read, and channel util estimate was never computed. RoutingChanUtilEstimator computes BBs in the routing stage and calculates channel utilization there
@soheilshahrouz
add doxygen comment for RoutingChanUtilEstimator
764bc14
@soheilshahrouz
update command_line_usage.rst with router_initial_acc_cost_chan_conge…
e9ceccd 
…stion_threshold and router_initial_acc_cost_chan_congestion_weight
@github-actions github-actions bot added the docs Documentation label Jun 18, 2025
@soheilshahrouz soheilshahrouz merged commit 39e5c88 into master Jun 20, 2025
33 checks passed
@soheilshahrouz soheilshahrouz deleted the temp_lookahead_chan_cong branch June 20, 2025 03:32
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@vaughnbetz vaughnbetz

Assignees
No one assigned
Labels
docs Documentation lang-cpp C/C++ code libvtrutil VPR VPR FPGA Placement & Routing Tool
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
3 participants
@soheilshahrouz @vaughnbetz @AmirhosseinPoolad