[bazel] allocate 5 cores per verilator test to allow for harness and overhead
An alternative to #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 <drewmacrae@google.com>
diff --git a/.bazelrc b/.bazelrc
index 2b9c1af..161691c 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -43,12 +43,12 @@
# 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
+# Configuration to override resource constrained test
+# scheduling. Enable with `--config=local_test_jobs_per_cpus`
+test:local_test_jobs_per_cpus --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. Setting
+# this will ignore tags like "cpu:5"
# We have verilator tests that take more than an hour to complete
test --test_timeout=60,300,1500,7200
