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

[Peter Zijlstra]

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.