Re: [PATCH v2 3/9] arm: Rely on generic printing of preemption model.

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2025-02-10 15:16:11 [+0000], Russell King (Oracle) wrote:
> On Mon, Feb 10, 2025 at 01:04:29PM +0100, Sebastian Andrzej Siewior wrote:
> > On 2025-02-03 15:16:26 [+0100], To linux-kernel@vger.kernel.org wrote:
> > > __die() invokes later __show_regs() -> show_regs_print_info() which
> > > prints the current preemption model.
> > > Remove it from the initial line.
> > > 
> > > Cc: Russell King <linux@armlinux.org.uk>
> > > Cc: linux-arm-kernel@lists.infradead.org
> > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > 
> > Is it okay, to route this via the sched tree?
> 
> Sorry, its not obvious where show_regs_print_info() prints this.
> dump_stack_print_info() itself doesn't directly. print_worker_info()
> doesn't. print_stop_info() doesn't. Not sure whether print_scx_info()
> does.
> 
> Maybe showing example output would help?

Patch 2/9 adds this. [ https://lore.kernel.org/all/20250203141632.440554-3-bigeasy@linutronix.de/ ]

This this applied, die("test") on ARM ends as:

[    1.595106] Kernel panic - not syncing: test
[    1.596044] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.14.0-rc2-00009-gb80a798df08c-dirty #13 PREEMPT 
[    1.596768] Tainted: [W]=WARN
[    1.596946] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022
[    1.597407] Call trace: 
[    1.598183]  unwind_backtrace from show_stack+0x10/0x14
[    1.599231]  show_stack from dump_stack_lvl+0x50/0x64
[    1.599492]  dump_stack_lvl from panic+0x114/0x358
[    1.599824]  panic from kernel_init+0x64/0x74
[    1.600048]  kernel_init from ret_from_fork+0x14/0x38
[    1.600349] Exception stack(0xdf829fb0 to 0xdf829ff8)
[    1.600730] 9fa0:                                     00000000 00000000 00000000 00000000
[    1.601102] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.601447] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    1.603163] ---[ end Kernel panic - not syncing: test ]---

Sebastian