[PATCH net-next] configs/debug: run and debug PREEMPT

Stanislav Fomichev
2025-04-02T17:23:07Z

Recent change [0] resulted in a "BUG: using __this_cpu_read() in
preemptible" splat [1]. PREEMPT kernels have additional requirements
on what can and can not run with/without preemption enabled.
Expose those constrains in the debug kernels.

0: https://lore.kernel.org/netdev/20250314120048.12569-2-justin.iurman@uliege.be/
1: https://lore.kernel.org/netdev/20250402094458.006ba2a7@kernel.org/T/#mbf72641e9d7d274daee9003ef5edf6833201f1bc

Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
---
kernel/configs/debug.config | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/configs/debug.config b/kernel/configs/debug.config
index 8aafd050b754..e81327d2cd63 100644
--- a/kernel/configs/debug.config
+++ b/kernel/configs/debug.config
@@ -112,3 +112,8 @@ CONFIG_BRANCH_PROFILE_NONE=y
CONFIG_DYNAMIC_FTRACE=y
CONFIG_FTRACE=y
CONFIG_FUNCTION_TRACER=y
+#
+# Preemption
+#
+CONFIG_DEBUG_PREEMPT=y
+CONFIG_PREEMPT=y
--
2.49.0