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GaloisInc / BESSPIN-CloudGFE

The AWS cloud deployment of the BESSPIN GFE platform.
Apache License 2.0
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improve FireSim simulation speeds #100

Closed dhand-galois closed 4 years ago

dhand-galois commented 4 years ago

Despite what is claimed in the documentation, adding trace support to FireSim builds can decrease simulation performance even when not saving the trace to a file. The trace data is still transferred over the host connection and then ignored.

Thankfully, there is a simple solution - the trace start and end cycles are configured into the FPGA-side bridge component at runtime. Setting +trace-end0=1 instead of +trace-end0=-1 achieves nearly the same performance as an AFI built without tracing support (within 1-2 effective MHz).

This issue will track updating the swpkg scripts for each processor to include this change.

dhand-galois commented 4 years ago

Some stats:

Test Actual FPGA Freq Tracing Support Simulated Freq Debian Boot (sec)
Test 1 100MHz Yes - end=-1 39-40MHz 351
Test 2 100MHz No 61.33MHz 229
Test 3 75MHz No 48.14MHz 286
Test 4 100MHz Yes - end=1 59.85MHz 231

Roughly 50% speedup.

kiniry commented 4 years ago

How does this get packaged into final FireSim builds of GFE and LMCO's and UMich's processors?

dhand-galois commented 4 years ago

This has been merged into the build flow as of #105 and into FETT-Target as of https://github.com/DARPA-SSITH-Demonstrators/SSITH-FETT-Target/commit/f5a31db05599e7999cee5098fb7093a1dce1321e. All of the stand-alone FireSim swpkgs on S3 have also been updated to include this fix. So closing this as complete.