A recent change in utrace necessitated a corresponding change to uprobes, which
had a ripple effect on our SystemTap-based ITrace code in Performance Inspector.
The uprobes code is currently embedded in the SystemTap project. The latest
release of SystemTap (0.8) has the updated uprobes, plus some uprobes
enhancements that allow the probing of functions by symbolic name versus a
virtual memory address for a given PID. This change greatly simplifies the
SystemTap-based ITrace, allowing us to remove a lot of extra code. The attached
patch (it-update.patch) changes the SystemTap-based ITrace code accordingly, as
well as including some minor cleanups.
Additionally, the stapitrace-readme.patch (attached) adds a statement to
src/stap/README that indicates that this SystemTap-based version of ITrace
depends on SystemTap 0.8.