diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2020-03-21 12:26:03 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-03-21 16:00:24 +0100 |
| commit | 49915ac35ca7b07c54295a72d905be5064afb89e (patch) | |
| tree | da7e2b9c50d6ecdfa94db8b0d409fcb1527681eb | |
| parent | 40db173965c05a1d803451240ed41707d5bd978d (diff) | |
lockdep: Annotate irq_work
Mark irq_work items with IRQ_WORK_HARD_IRQ which should be invoked in
hardirq context even on PREEMPT_RT. IRQ_WORK without this flag will be
invoked in softirq context on PREEMPT_RT.
Set ->irq_config to 1 for the IRQ_WORK items which are invoked in softirq
context so lockdep knows that these can safely acquire a spinlock_t.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200321113242.643576700@linutronix.de
| -rw-r--r-- | include/linux/irq_work.h | 2 | ||||
| -rw-r--r-- | include/linux/irqflags.h | 13 | ||||
| -rw-r--r-- | kernel/irq_work.c | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 1 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 1 |
5 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 02da997ad12c..3b752e80c017 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -18,6 +18,8 @@ /* Doesn't want IPI, wait for tick: */ #define IRQ_WORK_LAZY BIT(2) +/* Run hard IRQ context, even on RT */ +#define IRQ_WORK_HARD_IRQ BIT(3) #define IRQ_WORK_CLAIMED (IRQ_WORK_PENDING | IRQ_WORK_BUSY) diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 9c17f9c827aa..f23f540e0ebb 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -69,6 +69,17 @@ do { \ current->irq_config = 0; \ } while (0) +# define lockdep_irq_work_enter(__work) \ + do { \ + if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\ + current->irq_config = 1; \ + } while (0) +# define lockdep_irq_work_exit(__work) \ + do { \ + if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\ + current->irq_config = 0; \ + } while (0) + #else # define trace_hardirqs_on() do { } while (0) # define trace_hardirqs_off() do { } while (0) @@ -83,6 +94,8 @@ do { \ # define lockdep_softirq_exit() do { } while (0) # define lockdep_hrtimer_enter(__hrtimer) do { } while (0) # define lockdep_hrtimer_exit(__hrtimer) do { } while (0) +# define lockdep_irq_work_enter(__work) do { } while (0) +# define lockdep_irq_work_exit(__work) do { } while (0) #endif #if defined(CONFIG_IRQSOFF_TRACER) || \ diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 828cc30774bc..48b5d1b6af4d 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -153,7 +153,9 @@ static void irq_work_run_list(struct llist_head *list) */ flags = atomic_fetch_andnot(IRQ_WORK_PENDING, &work->flags); + lockdep_irq_work_enter(work); work->func(work); + lockdep_irq_work_exit(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d91c9156fab2..5066d1dd3077 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1113,6 +1113,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq != rnp->gp_seq && (rnp->ffmask & rdp->grpmask)) { init_irq_work(&rdp->rcu_iw, rcu_iw_handler); + atomic_set(&rdp->rcu_iw.flags, IRQ_WORK_HARD_IRQ); rdp->rcu_iw_pending = true; rdp->rcu_iw_gp_seq = rnp->gp_seq; irq_work_queue_on(&rdp->rcu_iw, rdp->cpu); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 4be756b88a48..3e2dc9b8858c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -245,6 +245,7 @@ static void nohz_full_kick_func(struct irq_work *work) static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = { .func = nohz_full_kick_func, + .flags = ATOMIC_INIT(IRQ_WORK_HARD_IRQ), }; /* |