Covered both trace inserts the enable service writes itself

2026-09-20T21:55:38Z

The enable records two running events so that a buffer handed to an analysis tool is never empty, and those two inserts are the only ones in the kernel that run inside the service that turns tracing on. The buffer pointer and the event enable bits are both set a few lines above, so neither can be found in any other state on the way in, and both inserts sat at 4 of 12. A new test enables with a buffer sized from the kernel's own structures to hold exactly one event, which puts both inserts on the wrap boundary, and with three notifications: one that counts, one that filters the running event's own class, and one that turns tracing off. The last two are what reach the second insert's filtered and no-buffer arms, and both are ordinary application behaviour rather than a contrivance - a notification that stops tracing is what an application capturing a single bufferful of history does. The forced-state passes hold one SMP protection across the write, the enable and the restore. tx_trace_enable.c:392 goes to 12 of 12 and :391 to 10 of 12 on the union of the eight configurations, from 4 each. The two arms left are the first insert's own copies of the filtered and no-buffer tests, which nothing can reach between the assignments above it and the insert. 133/133 in each of the eight, and 50 standalone repeats of the new test green in every one of them. Assisted-by: Claude Code (Opus 5)

threadx.git/test/smp/regression/threadx_trace_enable_trace_test.c, branch v6.4.1_cert

Covered both trace inserts the enable service writes itself