From ce6eeff91f9fd6d537a50b4392bbf4ed2d35691b Mon Sep 17 00:00:00 2001
From: Mikey Sklar <mikeysklar@gmail.com>
Date: Fri, 23 Oct 2026 12:54:50 -0700
Subject: [PATCH] CI: split the Zephyr tests into more parallel jobs

native_sim, native_sim_asan and native_sim_lfs each get their own job,
so each job builds one firmware instead of three on 4 cores. Each bsim
suite is split by the zephyr_sample marker, so the tests that build
Zephyr samples, the slowest part of the suite, run in their own job.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 .github/workflows/run-zephyr-tests.yml | 24 ++++++++++++++++++------
 ports/zephyr-cp/Makefile               |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/run-zephyr-tests.yml b/.github/workflows/run-zephyr-tests.yml
index d9518c2d834..ebdd5daba21 100644
--- a/.github/workflows/run-zephyr-tests.yml
+++ b/.github/workflows/run-zephyr-tests.yml
@@ -13,19 +13,31 @@ jobs:
     name: ${{ matrix.shard }}
     strategy:
       fail-fast: ${{ github.event_name == 'merge_group' }}
-      # One job per board family, so the bsim suites, which take the longest, run
-      # side by side instead of after each other.
+      # One job per board, so each job builds one firmware. Each bsim suite is also split
+      # by the zephyr_sample marker, so the tests that build Zephyr samples get their own job.
       matrix:
         include:
           - shard: native_sim
-            boards: native_native_sim native_native_sim_asan native_native_sim_lfs
-            pytest_args: tests/ --ignore=tests/bsim -n $(nproc) --dist loadfile
+            boards: native_native_sim
+            pytest_args: tests/ --ignore=tests/bsim -k 'not native_native_sim_asan and not native_native_sim_lfs' -n $(nproc) --dist loadfile
+          - shard: native_sim_asan
+            boards: native_native_sim_asan
+            pytest_args: tests/ --ignore=tests/bsim -k native_native_sim_asan -n $(nproc) --dist loadfile
+          - shard: native_sim_lfs
+            boards: native_native_sim_lfs
+            pytest_args: tests/ --ignore=tests/bsim -k native_native_sim_lfs -n $(nproc) --dist loadfile
           - shard: nrf5340bsim
             boards: native_nrf5340bsim
-            pytest_args: tests/bsim -k native_nrf5340bsim -n $(nproc) --dist loadfile
+            pytest_args: tests/bsim -k native_nrf5340bsim -m 'not zephyr_sample' -n $(nproc) --dist loadfile
+          - shard: nrf5340bsim-samples
+            boards: native_nrf5340bsim
+            pytest_args: tests/bsim -k native_nrf5340bsim -m zephyr_sample -n $(nproc) --dist loadfile
           - shard: nrf54lm20bsim
             boards: native_nrf54lm20bsim
-            pytest_args: tests/bsim -k native_nrf54lm20bsim -n $(nproc) --dist loadfile
+            pytest_args: tests/bsim -k native_nrf54lm20bsim -m 'not zephyr_sample' -n $(nproc) --dist loadfile
+          - shard: nrf54lm20bsim-samples
+            boards: native_nrf54lm20bsim
+            pytest_args: tests/bsim -k native_nrf54lm20bsim -m zephyr_sample -n $(nproc) --dist loadfile
     env:
       CP_VERSION: ${{ inputs.cp-version }}
     steps:
diff --git a/ports/zephyr-cp/Makefile b/ports/zephyr-cp/Makefile
index adb1d658ee6..5d5554c4fbc 100644
--- a/ports/zephyr-cp/Makefile
+++ b/ports/zephyr-cp/Makefile
@@ -257,7 +257,7 @@ test-build-$(1):
 endef
 $(foreach board,$(TEST_BOARDS),$(eval $(call test_board_rule,$(board))))
 
-# CI runs this as three jobs, one per board family, narrowing TEST_BOARDS and
+# CI splits this into several jobs, one board each, narrowing TEST_BOARDS and
 # PYTEST_ARGS; see .github/workflows/run-zephyr-tests.yml.
 PYTEST_ARGS ?= tests/