Re: [PATCH 3/4] locking/mutex: Pass proper call-site ip

[Steven Rostedt]

On Tue, 1 Mar 2022 10:05:12 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Mon, Feb 28, 2022 at 05:04:11PM -0800, Namhyung Kim wrote:
> > The __mutex_lock_slowpath() and friends are declared as noinline and
> > _RET_IP_ returns its caller as mutex_lock which is not meaningful.
> > Pass the ip from mutex_lock() to have actual caller info in the trace.  
> 
> Blergh, can't you do a very limited unwind when you do the tracing
> instead? 3 or 4 levels should be plenty fast and sufficient.

Is there a fast and sufficient way that works across architectures?

Could objtool help here?

-- Steve