diff options
Diffstat (limited to 'kernel/rcu/update.c')
| -rw-r--r-- | kernel/rcu/update.c | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index f19271dce0a9..9e03db9ea9c0 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -121,27 +121,30 @@ EXPORT_SYMBOL(rcu_read_lock_sched_held); * Should expedited grace-period primitives always fall back to their * non-expedited counterparts? Intended for use within RCU. Note * that if the user specifies both rcu_expedited and rcu_normal, then - * rcu_normal wins. + * rcu_normal wins. (Except during the time period during boot from + * when the first task is spawned until the rcu_exp_runtime_mode() + * core_initcall() is invoked, at which point everything is expedited.) */ bool rcu_gp_is_normal(void) { - return READ_ONCE(rcu_normal); + return READ_ONCE(rcu_normal) && + rcu_scheduler_active != RCU_SCHEDULER_INIT; } EXPORT_SYMBOL_GPL(rcu_gp_is_normal); -static atomic_t rcu_expedited_nesting = - ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0); +static atomic_t rcu_expedited_nesting = ATOMIC_INIT(1); /* * Should normal grace-period primitives be expedited? Intended for * use within RCU. Note that this function takes the rcu_expedited - * sysfs/boot variable into account as well as the rcu_expedite_gp() - * nesting. So looping on rcu_unexpedite_gp() until rcu_gp_is_expedited() - * returns false is a -really- bad idea. + * sysfs/boot variable and rcu_scheduler_active into account as well + * as the rcu_expedite_gp() nesting. So looping on rcu_unexpedite_gp() + * until rcu_gp_is_expedited() returns false is a -really- bad idea. */ bool rcu_gp_is_expedited(void) { - return rcu_expedited || atomic_read(&rcu_expedited_nesting); + return rcu_expedited || atomic_read(&rcu_expedited_nesting) || + rcu_scheduler_active == RCU_SCHEDULER_INIT; } EXPORT_SYMBOL_GPL(rcu_gp_is_expedited); @@ -178,8 +181,7 @@ EXPORT_SYMBOL_GPL(rcu_unexpedite_gp); */ void rcu_end_inkernel_boot(void) { - if (IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT)) - rcu_unexpedite_gp(); + rcu_unexpedite_gp(); if (rcu_normal_after_boot) WRITE_ONCE(rcu_normal, 1); } @@ -257,7 +259,7 @@ EXPORT_SYMBOL_GPL(rcu_callback_map); int notrace debug_lockdep_rcu_enabled(void) { - return rcu_scheduler_active && debug_locks && + return rcu_scheduler_active != RCU_SCHEDULER_INACTIVE && debug_locks && current->lockdep_recursion == 0; } EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled); @@ -591,7 +593,7 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks); void synchronize_rcu_tasks(void) { /* Complain if the scheduler has not started. */ - RCU_LOCKDEP_WARN(!rcu_scheduler_active, + RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE, "synchronize_rcu_tasks called too soon"); /* Wait for the grace period. */ @@ -813,6 +815,23 @@ static void rcu_spawn_tasks_kthread(void) #endif /* #ifdef CONFIG_TASKS_RCU */ +/* + * Test each non-SRCU synchronous grace-period wait API. This is + * useful just after a change in mode for these primitives, and + * during early boot. + */ +void rcu_test_sync_prims(void) +{ + if (!IS_ENABLED(CONFIG_PROVE_RCU)) + return; + synchronize_rcu(); + synchronize_rcu_bh(); + synchronize_sched(); + synchronize_rcu_expedited(); + synchronize_rcu_bh_expedited(); + synchronize_sched_expedited(); +} + #ifdef CONFIG_PROVE_RCU /* @@ -865,6 +884,7 @@ void rcu_early_boot_tests(void) early_boot_test_call_rcu_bh(); if (rcu_self_test_sched) early_boot_test_call_rcu_sched(); + rcu_test_sync_prims(); } static int rcu_verify_early_boot_tests(void) |