Functions not getting picked up by dtrace

[Mark Johnston]

On Mon, Feb 29, 2016 at 01:39:33PM -0800, hiren panchasara wrote:
> I've seen this earlier with others too but this one is the latest
> confusing me: em_xmit() in $src/dev/e1000/if_em.c
> 
> Other functions with similar signature are listed in 'dtrace -l'.

em_xmit() is a static function with a single call site, so it's getting
inlined into its caller. DTrace FBT can't instrument inlined functions.

> 
> Is is because of some optimization? How do I undo it for testing
> purposes?

There's a __noinline attribute that you can use for this.