Hi, Bisect pointed commit ce3147990450a68b3f549088b30f087742a08b5d ("fs/locks: allow a lock request to block other requests.") to failure boot of NFSv4 with root on several boards. Log is here: https://krzk.eu/#/builders/21/builds/836/steps/12/logs/serial0 With several errors: kernel BUG at ../fs/locks.c:336! Unable to handle kernel NULL pointer dereference at virtual address 00000004 Configuration: 1. exynos_defconfig 2. Arch ARM Linux 3. Boards: a. Odroid family (ARMv7, octa-core (Cortex-A7+A15), Exynos5422 SoC) b. Toradex Colibri VF50 (ARMv7, UP, Cortex-A5) 4. Systemd: v236, 238 5. All boards boot from TFTP with NFS root (NFSv4) On Colibri VF50 I got slightly different errors: [ 11.663204] Internal error: Oops - undefined instruction: 0 [#1] ARM [ 12.455273] Unable to handle kernel NULL pointer dereference at virtual address 00000004 and only with some specific GCC (v6.3) or with other conditions which I did not bisect yet. Maybe Colibri's failure is unrelated to that commit. Best regards, Krzysztof