Re: [RFC PATCH 0/2] sysctl: Panic on RCU stall and schedule while atomic

Christian Borntraeger
2016-05-31T19:27:32Z

On 05/31/2016 09:07 PM, Daniel Bristot de Oliveira wrote:
> This patch series implements two kernel.panic_on_* like sysctl:
>
> kernel.panic_on_rcu_stall:
> panic() on RCU Stall detection.
>
> kernel.panic_on_sched_in_atomic:
> panic() on schedule while atomic detection.
>
> These sysctls are useful to capture a vmcore when is not possible
> to recompile the kernel to include the panic() call. For instance
> when supporting enterprise users.
>
> Daniel Bristot de Oliveira (2):
> rcu: sysctl: Panic on RCU Stall
> sched: sysctl: Panic on scheduling while atomic
>
> Documentation/sysctl/kernel.txt | 25 +++++++++++++++++++++++++
> include/linux/kernel.h | 2 ++
> kernel/rcu/tree.c | 8 ++++++++
> kernel/sched/core.c | 7 +++++++
> kernel/sysctl.c | 20 ++++++++++++++++++++
> 5 files changed, 62 insertions(+)

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>

for both changes. I too often had to add manual panics in a test
kernel and reproduce an issue. This will allow to take a (k)dump at a point
in time where the data structures might still explain what happened.
As this is an opt-in nobody, this should not cause any trouble for
people that do not want to take dumps.

Christian