From: Peter Zijlstra <[email protected]> The try_invoke_on_locked_down_task() function currently requires that interrupts be enabled, but it is called with interrupts disabled from rcu_print_task_stall(), resulting in an "IRQs not enabled as expected" diagnostic. This commit therefore updates try_invoke_on_locked_down_task() to use raw_spin_lock_irqsave() instead of raw_spin_lock_irq(), thus allowing use from either context.
Link: https://lore.kernel.org/lkml/[email protected]/ Link: https://lore.kernel.org/lkml/[email protected]/ Reported-by: [email protected] Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/sched/core.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e7e4534..f768bb0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2989,7 +2989,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) /** * try_invoke_on_locked_down_task - Invoke a function on task in fixed state - * @p: Process for which the function is to be invoked. + * @p: Process for which the function is to be invoked, can be @current. * @func: Function to invoke. * @arg: Argument to function. * @@ -3007,12 +3007,11 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg) { - bool ret = false; struct rq_flags rf; + bool ret = false; struct rq *rq; - lockdep_assert_irqs_enabled(); - raw_spin_lock_irq(&p->pi_lock); + raw_spin_lock_irqsave(&p->pi_lock, rf.flags); if (p->on_rq) { rq = __task_rq_lock(p, &rf); if (task_rq(p) == rq) @@ -3029,7 +3028,7 @@ bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct t ret = func(p, arg); } } - raw_spin_unlock_irq(&p->pi_lock); + raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); return ret; } -- 2.9.5
