IntelĀ® Trace Collector 9.1 Update 2 User and Reference Guide
PCTRACE-FAST [on|off]
VT_PCTRACE_FAST
on for performance tracing, off for correctness checking
Controls whether the fast, but less reliable stack unwinding is used or the slower, but less error-prone unwinding through libunwind. The fast unwinding relies on frame pointers, therefore all code must be compiled accordingly for it to work correctly.