diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-21 22:05:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-05-26 19:05:11 +0200 |
| commit | 07325d4a90d2d84de45cc07b134fd0f023dbb971 (patch) | |
| tree | 0c0437193ef9e2501abb778d25a7f5a3d3429935 /kernel/rcu | |
| parent | aaf2bc50df1f4bfc6857fc601fc7b21d5a18c6a1 (diff) | |
rcu: Provide rcu_irq_exit_check_preempt()
Provide a debug check which can be invoked from exception return to kernel
mode before an attempt is made to schedule. Warn if RCU is not ready for
this.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.089709607@linutronix.de
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index b7f8c494d1d1..d8e9dbbefcfa 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -765,6 +765,24 @@ void rcu_irq_exit_preempt(void) "RCU in extended quiescent state!"); } +#ifdef CONFIG_PROVE_RCU +/** + * rcu_irq_exit_check_preempt - Validate that scheduling is possible + */ +void rcu_irq_exit_check_preempt(void) +{ + lockdep_assert_irqs_disabled(); + + RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) <= 0, + "RCU dynticks_nesting counter underflow/zero!"); + RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nmi_nesting) != + DYNTICK_IRQ_NONIDLE, + "Bad RCU dynticks_nmi_nesting counter\n"); + RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(), + "RCU in extended quiescent state!"); +} +#endif /* #ifdef CONFIG_PROVE_RCU */ + /* * Wrapper for rcu_irq_exit() where interrupts are enabled. * |