LTTng and the out-of-tree tracer catch-22, from Plumbers 2026
from the export-symbol-or-bust dept.
Two decades of LTTng, and its maintainer still cannot upstream it piece by piece because the kernel will not export symbols with no in-tree user. Jake Edge's write-up is a fair, detailed look at a real engineering knot rather than a flame war. Anyone who has carried an out-of-tree module will nod along.
At the Linux Plumbers Conference, Mathieu Desnoyers led a session on how LTTng could work better alongside ftrace and perf. The discussion covered the rule against exporting unused symbols, duplicated tracing infrastructure, different ring-buffer needs, and whether a middle path exists between staying out of tree and merging everything at once.
Read the rest of this story (LWN.net)
