On Wed, 9 Jan 2019 20:38:51 -0500 (EST) Mathieu Desnoyers <[email protected]> wrote:
> Hi Paul, > > I've had a user report that trace_sched_waking() appears to be > invoked while !rcu_is_watching() in some situation, so I started > digging into the scheduler idle code. I'm wondering if this isn't a bug. Do you have the backtrace for where trace_sched_waking() was called without rcu watching? -- Steve > > It appears that interrupts are re-enabled before rcu_eqs_exit() is > invoked when exiting idle code from the scheduler. > > I wonder what happens if an interrupt handler (including scheduler code) > happens to issue a RCU read-side critical section before rcu_eqs_exit() > is called ? Is there some code on interrupt entry that ensures rcu eqs > state is exited in such scenario ? > > Thanks, > > Mathieu >
