diff options
| author | Frederic Weisbecker <frederic@kernel.org> | 2021-04-09 00:38:59 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-05-10 16:03:35 -0700 |
| commit | 8e9c01c717df7e05c5bd1ca86aaa3a74b31f37f1 (patch) | |
| tree | 8f58eebf79cb94cd852cb024c231d2b1fe03332d /kernel | |
| parent | 7bf0a6141ab9c1d113bd85d6d13d43903a4278ba (diff) | |
srcu: Initialize SRCU after timers
Once srcu_init() is called, the SRCU core will make use of delayed
workqueues, which rely on timers. However init_timers() is called
several steps after rcu_init(). This means that a call_srcu() after
rcu_init() but before init_timers() would find itself within a dangerously
uninitialized timer core.
This commit therefore creates a separate call to srcu_init() after
init_timer() completes, which ensures that we stay in early SRCU mode
until timers are safe(r).
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcu.h | 6 | ||||
| -rw-r--r-- | kernel/rcu/srcutree.c | 5 | ||||
| -rw-r--r-- | kernel/rcu/tiny.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 1 |
4 files changed, 5 insertions, 8 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index bf0827d4b659..ca3f2af32bf8 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -422,12 +422,6 @@ do { \ #endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */ -#ifdef CONFIG_SRCU -void srcu_init(void); -#else /* #ifdef CONFIG_SRCU */ -static inline void srcu_init(void) { } -#endif /* #else #ifdef CONFIG_SRCU */ - #ifdef CONFIG_TINY_RCU /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ static inline bool rcu_gp_is_normal(void) { return true; } diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index f4f0cbf7a02b..9ec35c158740 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1384,6 +1384,11 @@ void __init srcu_init(void) { struct srcu_struct *ssp; + /* + * Once that is set, call_srcu() can follow the normal path and + * queue delayed work. This must follow RCU workqueues creation + * and timers initialization. + */ srcu_init_done = true; while (!list_empty(&srcu_boot_list)) { ssp = list_first_entry(&srcu_boot_list, struct srcu_struct, diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index c8a029fbb114..340b3f8b090d 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -221,5 +221,4 @@ void __init rcu_init(void) { open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); rcu_early_boot_tests(); - srcu_init(); } diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8e78b2430c16..c35b15229cff 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4735,7 +4735,6 @@ void __init rcu_init(void) WARN_ON(!rcu_gp_wq); rcu_par_gp_wq = alloc_workqueue("rcu_par_gp", WQ_MEM_RECLAIM, 0); WARN_ON(!rcu_par_gp_wq); - srcu_init(); /* Fill in default value for rcutree.qovld boot parameter. */ /* -After- the rcu_node ->lock fields are initialized! */ |