Re: [patch] sched: fix single-depth wchan output

[Ken Chen <kenchen@google.com>]

On Wed, Nov 5, 2008 at 10:11 PM, Ingo Molnar <mingo@elte.hu> wrote:
> hm, this adds overhead - and the thing is that WCHAN is rather
> uninformative to begin with (because it's a single dimension), so we
> should phase it out, not expand it.
>
> How about adding a /proc/<PID>/stacktrace file that gives us the stack
> trace of any task in the system? That would be useful for a number of
> other purposes as well, and about 100 times more useful than wchan.
> (often it would be more useful than sysrq-t dumps)

Sure, my main motivation is to remove frame pointer generation. x86_64
unconditionally adds fp for kernel/sched.c right now.  I'm all for
phasing out wchan if people don't think there is value in it.

- Ken