Re: [PATCH] watchdog: Force console verbose when reporting lockups

[Doug Anderson]

Hi,

On Tue, Oct 6, 2026 at 10:17 PM Tzung-Bi Shih <tzungbi@xxxxxxxxxx> wrote:
>
> When a hard or soft lockup is detected, the watchdog prints a header at
> KERN_EMERG (<0>), followed by diagnostic details (modules, registers,
> and backtraces) at KERN_WARNING/KERN_DEFAULT (<4>) and KERN_INFO (<6>).
> If console_loglevel is quiet (<= 4), the console skips those <4>/<6>
> diagnostic messages before vpanic() has a chance to call
> console_verbose().  With the buddy detector, this leaves only the
> detector CPU's panic stack on the console and nothing about the locked
> CPU:
>
>   <0>[ 1535.991833][    C6] watchdog: Watchdog detected hard LOCKUP on cpu 7
>   <0>[ 1535.995960][    C6] Kernel panic - not syncing: Hard LOCKUP
>   <4>[ 1535.995970][    C6] CPU: 6 UID: 0 PID: 0 Comm: swapper/6 ...
>   <4>[ 1535.995997][    C6] Call trace:
>   ...
>   <4>[ 1535.996063][    C6]  watchdog_hardlockup_check+0x1e0/0x288
>   <4>[ 1535.996075][    C6]  watchdog_buddy_check_hardlockup+0xb4/0xc0
>
> Similar to commit 168e06f7937d ("kernel/hung_task.c: force console
> verbose before panic"), call console_verbose() before printing the
> lockup report so the diagnostic output is not suppressed.
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> ---
>  kernel/watchdog.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>