copy faults from user_string* functions

[Frank Ch. Eigler]

Hi, Eric -

On Fri, Jul 26, 2013 at 05:56:02PM +0000, Eric Wong wrote:
> [...]
> Is there any optional way to get stap to trigger page faults to get
> that data?

Not easily.  Perhaps from the tracing site, the code could load a few
bytes of the strings whose addresses are being passed.  Perhaps try an
mlock() or some other explicit data-segment-dereference loop during
program startup?

> When tracing, losing a little performance is OK, especially with
> cmogstored (which is entirely network/disk bound).

Understood.

- FChE