diff options
author | Paul E. McKenney | 2017-05-26 16:16:40 -0700 |
---|---|---|
committer | Paul E. McKenney | 2017-07-24 16:03:22 -0700 |
commit | 825c5bd2fd47d30148db15fc121216c483682b01 (patch) | |
tree | b31f9dae8649d26b1cbbda9f8821ba2c917c13a1 | |
parent | 520eccdfe187591a51ea9ab4c1a024ae4d0f68d9 (diff) |
srcu: Move rcu_scheduler_starting() from Tiny RCU to Tiny SRCU
Other than lockdep support, Tiny RCU has no need for the
scheduler status. However, Tiny SRCU will need this to control
boot-time behavior independent of lockdep. Therefore, this commit
moves rcu_scheduler_starting() from kernel/rcu/tiny_plugin.h to
kernel/rcu/srcutiny.c. This in turn allows the complete removal of
kernel/rcu/tiny_plugin.h.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-rw-r--r-- | include/linux/rcupdate.h | 1 | ||||
-rw-r--r-- | include/linux/rcutiny.h | 8 | ||||
-rw-r--r-- | kernel/rcu/srcutiny.c | 8 | ||||
-rw-r--r-- | kernel/rcu/tiny.c | 2 | ||||
-rw-r--r-- | kernel/rcu/tiny_plugin.h | 47 |
5 files changed, 12 insertions, 54 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index f816fc72b51e..55c29e1650b9 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -105,6 +105,7 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); +extern int rcu_scheduler_active __read_mostly; void rcu_sched_qs(void); void rcu_bh_qs(void); void rcu_check_callbacks(int user); diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 5becbbccb998..b3dbf9502fd0 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -116,13 +116,11 @@ static inline void rcu_irq_exit_irqson(void) { } static inline void rcu_irq_enter_irqson(void) { } static inline void rcu_irq_exit(void) { } static inline void exit_rcu(void) { } - -#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SRCU) -extern int rcu_scheduler_active __read_mostly; +#ifdef CONFIG_SRCU void rcu_scheduler_starting(void); -#else /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SRCU) */ +#else /* #ifndef CONFIG_SRCU */ static inline void rcu_scheduler_starting(void) { } -#endif /* #else #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SRCU) */ +#endif /* #else #ifndef CONFIG_SRCU */ static inline void rcu_end_inkernel_boot(void) { } static inline bool rcu_is_watching(void) { return true; } diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 1a1c1047d2ed..76ac5f50b2c7 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -33,6 +33,8 @@ #include "rcu_segcblist.h" #include "rcu.h" +int rcu_scheduler_active __read_mostly; + static int init_srcu_struct_fields(struct srcu_struct *sp) { sp->srcu_lock_nesting[0] = 0; @@ -193,3 +195,9 @@ void synchronize_srcu(struct srcu_struct *sp) destroy_rcu_head_on_stack(&rs.head); } EXPORT_SYMBOL_GPL(synchronize_srcu); + +/* Lockdep diagnostics. */ +void __init rcu_scheduler_starting(void) +{ + rcu_scheduler_active = RCU_SCHEDULER_RUNNING; +} diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index f8488965250f..a64eee0db39e 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -56,8 +56,6 @@ static struct rcu_ctrlblk rcu_bh_ctrlblk = { .curtail = &rcu_bh_ctrlblk.rcucblist, }; -#include "tiny_plugin.h" - void rcu_barrier_bh(void) { wait_rcu_gp(call_rcu_bh); diff --git a/kernel/rcu/tiny_plugin.h b/kernel/rcu/tiny_plugin.h deleted file mode 100644 index f0a01b2a3062..000000000000 --- a/kernel/rcu/tiny_plugin.h +++ /dev/null @@ -1,47 +0,0 @@ -/* - * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition - * Internal non-public definitions that provide either classic - * or preemptible semantics. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * - * Copyright (c) 2010 Linaro - * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> - */ - -#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SRCU) -#include <linux/kernel_stat.h> - -int rcu_scheduler_active __read_mostly; -EXPORT_SYMBOL_GPL(rcu_scheduler_active); - -/* - * During boot, we forgive RCU lockdep issues. After this function is - * invoked, we start taking RCU lockdep issues seriously. Note that unlike - * Tree RCU, Tiny RCU transitions directly from RCU_SCHEDULER_INACTIVE - * to RCU_SCHEDULER_RUNNING, skipping the RCU_SCHEDULER_INIT stage. - * The reason for this is that Tiny RCU does not need kthreads, so does - * not have to care about the fact that the scheduler is half-initialized - * at a certain phase of the boot process. Unless SRCU is in the mix. - */ -void __init rcu_scheduler_starting(void) -{ - WARN_ON(nr_context_switches() > 0); - rcu_scheduler_active = IS_ENABLED(CONFIG_SRCU) - ? RCU_SCHEDULER_INIT : RCU_SCHEDULER_RUNNING; -} - -#endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SRCU) */ |