Examples of techniques for packet flow tracing in a parallel processor complex are disclosed. In one example implementation according to aspects of the present disclosure, a computer-implemented method may include receiving, at the parallel processor complex, a task to be executed by the parallel processor complex, wherein the parallel processor complex comprises a trace processor and a plurality of task execution processors; creating, by the trace processor, a trace entry by allocating an element from a shared queue; loading, by the trace processor, the trace entry into a common trace buffer; and loading, by the trace processor, the trace entry into a host interface/queue pair index trace buffer.