[bazel] allocate 5 cores per verilator test to allow for harness and …

…overhead An alternative to lowRISC#16913 to prevent harnesses from getting pre-empted by a simulation load. We also stop overriding resource based allocation by removing --local_test_jobs arg and update documentation Signed-off-by: Drew Macrae <[email protected]>
drewmacrae · Dec 22, 2022 · e6bd406 · e6bd406
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commit e6bd406
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Showing 2 changed files with 6 additions and 7 deletions.
diff --git a/.bazelrc b/.bazelrc
@@ -43,12 +43,11 @@ coverage:coverage_clang --repo_env=BAZEL_LLVM_COV=/usr/bin/llvm-cov
 # cached previously. See https://bazel.build/configure/coverage?hl=en#remote-execution
 coverage:coverage_clang --nocache_test_results
 
-# Verilator is built for 4 cores and can time out if bazel is running more
-# than 1 test per four cores.
-# Until we get the built-in tag "cpu:4" to work for verilator tests, we can run
-# 1 test per 4 cores to avoid verilator performance falloff and timeouts we'd
-# otherwise see on machines with fewer than 40 cores.
-test --local_test_jobs=HOST_CPUS*0.25
+# # Uncomment this or add to ~/.bazelrc to override resource constrained test
+# # scheduling.
+# test --local_test_jobs=HOST_CPUS*0.22
+# # Verilator is built for 4 cores, but requires a harness and additional overhead.
+# # Empirically 72 cores can support 16 simultaneous tests, but not 17.
 
 # We have verilator tests that take more than an hour to complete
 test --test_timeout=60,300,1500,7200

diff --git a/rules/opentitan_test.bzl b/rules/opentitan_test.bzl
@@ -152,7 +152,7 @@ def verilator_params(
         "@//hw:verilator",
         "@//hw:fusesoc_ignore",
     ]
-    required_tags = ["verilator", "cpu:4"]
+    required_tags = ["verilator", "cpu:5"]
     kwargs.update(
         args = default_args + args,
         data = required_data + data,