Re: [PATCH -v4 9/9] tracing: add function graph tracer support forMIPS

[Steven Rostedt]

On Thu, 2009-10-22 at 08:59 -0700, David Daney wrote:

> This is what I was talking about up-thread.  Leaf functions may have no 
> function prolog.  If you do code scanning you will fail.  While scanning 
> backwards, there is no way to know when you have entered a new function. 
>   Looking for function return sequences 'jr ra' doesn't work as there 
> may be functions with multiple return sites, functions that never 
> return, or arbitrary data before the function.  I think you have to 
> force a frame pointer to be established if you want this to work.

Functions that run off into another function?? I guess the compiler
could do that, but with -pg enable, I would think is broken.

-- Steve


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/