[PATCH v2] powerpc: allow configuring max stack dump depth

[Paul Mackerras]

Johannes Berg writes:

> On my screen, when something crashes, I only have space for maybe
> 16 functions of the stack trace before the information above it
> scrolls off the screen. It's easy to hack the kernel to print out
> only that much, but it's harder to remember to do it. This patch
> introduces a config option for it so that I can keep the setting
> in my config.
> 
> Signed-off-by: Johannes Berg <johannes at sipsolutions.net>
> ---
> Sure, here's an updated version. I used DEBUG_KERNEL since the
> ADVANCED_CONFIGURATION help text implies it's for MM and can cause the
> kernel to not boot, not something this config is related to.

Um, with this I get a compile error when DEBUG_KERNEL=n:

  CC      arch/powerpc/kernel/process.o
/home/paulus/kernel/powerpc/arch/powerpc/kernel/process.c:1001: error: 'CONFIG_PRINT_STACK_DEPTH' undeclared here (not in a function)
make[2]: *** [arch/powerpc/kernel/process.o] Error 1

I think it needs to look like this:

+config PRINT_STACK_DEPTH
+	int "Stack depth to print" if DEBUG_KERNEL
+	default 64
+	help
+	  This option allows you to set the stack depth that the kernel
+	  prints in stack traces. This can be useful if your display is
+	  too small and stack traces cause important information to
+	  scroll off the screen.
+

Paul.