[PATCH v2 0/9] tracing vs rcu vs nmi

Peter Zijlstra
2020-02-12T21:14:08Z

Hi all,

These here patches are the result of Mathieu and Steve trying to get commit
865e63b04e9b2 ("tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle
tracepoints") reverted again.

One of the things discovered is that tracing MUST NOT happen before nmi_enter()
or after nmi_exit(). Audit results of the previous version are still valid.

Changes since -v1:

- Added tags
- Changed #4; changed nmi_enter() to use __preempt_count_add() vs
marking preempt_count_add() notrace.
- Changed #5; confusion on which functions are notrace due to Makefile
- Added #9; remove limitation on the perf-function-trace coupling