Re: [PATCH] panic/kexec: Allow forcing panic execution on a specific CPU
From: Andrew Morton
Date: Sat Jan 03 2026 - 13:29:34 EST
On Thu, 1 Jan 2026 14:32:37 +0200 Pnina Feder <pnina.feder@xxxxxxxxxxxx> wrote:
> Some platforms require panic handling to execute on a specific CPU
> for crash dump to work reliably. This may be due to firmware,
> interrupt routing, or platform-specific constraints where only one
> CPU is able to safely enter the crash kernel.
>
> Add an optional configuration that allows redirecting panic execution
> to a designated target CPU before invoking kexec into the crash kernel.
>
> When CONFIG_PANIC_FORCE_CPU is enabled, the initial panic CPU will
> forward the panic to the configured CPU using smp_call_function_single().
> If a panic is already in progress on another CPU, redirection is
> skipped and a warning is printed.
Requiring a recompile/reinstall isn't very user-friendly. Is it
possible to do this with a kernel boot option?