Goal

As a support engineer performing deep-dive live analysis with bpftrace or SystemTap, I need USDT probes compiled into production RPMs so I can attach dynamic tracing to ns-slapd without recompiling or restarting.

STAP_PROBE points already exist in the codebase and 3 example SystemTap scripts ship in profiling/stap/, but production RPMs compile without --enable-systemtap and don't list systemtap-sdt-devel in BuildRequires. The probes compile to single NOP instructions with zero overhead when not traced.

Add systemtap-sdt-devel to BuildRequires and pass --enable-systemtap in %configure. Add new probes for work queue operations: work_q_enqueue, work_q_dequeue, worker_busy, worker_idle – these complement the existing probes with thread pool lifecycle coverage. When tracing is attached, the kernel replaces each NOP with an INT3 trap – same privilege model as gdb/strace.

Acceptance criteria

• Verify the RPM builds successfully with --enable-systemtap enabled
• Verify existing probe points are present in the built binary (check via readelf -n or tplist)
• Verify the 4 new work queue probes fire correctly when traced with bpftrace under load
• Verify the existing SystemTap scripts in profiling/stap/ work against the new build