mirror of
https://github.com/adulau/aha.git
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Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: fix requeue_pi key imbalance futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions rcu: Place root rcu_node structure in separate lockdep class rcu: Make hot-unplugged CPU relinquish its own RCU callbacks rcu: Move rcu_barrier() to rcutree futex: Move exit_pi_state() call to release_mm() futex: Nullify robust lists after cleanup futex: Fix locking imbalance panic: Fix panic message visibility by calling bust_spinlocks(0) before dying rcu: Replace the rcu_barrier enum with pointer to call_rcu*() function rcu: Clean up code based on review feedback from Josh Triplett, part 4 rcu: Clean up code based on review feedback from Josh Triplett, part 3 rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=y rcu: Clean up code to address Ingo's checkpatch feedback rcu: Clean up code based on review feedback from Josh Triplett, part 2 rcu: Clean up code based on review feedback from Josh Triplett
This commit is contained in:
commit
f579bbcd9b
14 changed files with 405 additions and 316 deletions
|
@ -33,8 +33,8 @@
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|||
#define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
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#define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
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#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
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#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITS | FUTEX_PRIVATE_FLAG)
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#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITS | FUTEX_PRIVATE_FLAG)
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#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)
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#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)
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#define FUTEX_WAIT_REQUEUE_PI_PRIVATE (FUTEX_WAIT_REQUEUE_PI | \
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FUTEX_PRIVATE_FLAG)
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#define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \
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@ -77,7 +77,7 @@ extern int rcu_scheduler_active;
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#error "Unknown RCU implementation specified to kernel configuration"
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#endif
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#define RCU_HEAD_INIT { .next = NULL, .func = NULL }
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#define RCU_HEAD_INIT { .next = NULL, .func = NULL }
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#define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT
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#define INIT_RCU_HEAD(ptr) do { \
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(ptr)->next = NULL; (ptr)->func = NULL; \
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@ -129,12 +129,6 @@ static inline void rcu_read_lock(void)
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rcu_read_acquire();
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}
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/**
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* rcu_read_unlock - marks the end of an RCU read-side critical section.
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*
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* See rcu_read_lock() for more information.
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*/
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/*
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* So where is rcu_write_lock()? It does not exist, as there is no
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* way for writers to lock out RCU readers. This is a feature, not
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@ -144,6 +138,12 @@ static inline void rcu_read_lock(void)
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* used as well. RCU does not care how the writers keep out of each
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* others' way, as long as they do so.
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*/
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/**
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* rcu_read_unlock - marks the end of an RCU read-side critical section.
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*
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* See rcu_read_lock() for more information.
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*/
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static inline void rcu_read_unlock(void)
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{
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rcu_read_release();
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@ -196,6 +196,8 @@ static inline void rcu_read_lock_sched(void)
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__acquire(RCU_SCHED);
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rcu_read_acquire();
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}
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/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
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static inline notrace void rcu_read_lock_sched_notrace(void)
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{
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preempt_disable_notrace();
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@ -213,6 +215,8 @@ static inline void rcu_read_unlock_sched(void)
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__release(RCU_SCHED);
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preempt_enable();
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}
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/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
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static inline notrace void rcu_read_unlock_sched_notrace(void)
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{
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__release(RCU_SCHED);
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@ -30,10 +30,14 @@
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#ifndef __LINUX_RCUTREE_H
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#define __LINUX_RCUTREE_H
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struct notifier_block;
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extern void rcu_sched_qs(int cpu);
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extern void rcu_bh_qs(int cpu);
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extern int rcu_cpu_notify(struct notifier_block *self,
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unsigned long action, void *hcpu);
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extern int rcu_needs_cpu(int cpu);
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extern int rcu_expedited_torture_stats(char *page);
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#ifdef CONFIG_TREE_PREEMPT_RCU
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@ -85,16 +89,11 @@ static inline void synchronize_rcu_bh_expedited(void)
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extern void __rcu_init(void);
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extern void rcu_check_callbacks(int cpu, int user);
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extern void rcu_restart_cpu(int cpu);
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extern long rcu_batches_completed(void);
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extern long rcu_batches_completed_bh(void);
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extern long rcu_batches_completed_sched(void);
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static inline void rcu_init_sched(void)
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{
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}
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#ifdef CONFIG_NO_HZ
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void rcu_enter_nohz(void);
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void rcu_exit_nohz(void);
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@ -107,7 +106,7 @@ static inline void rcu_exit_nohz(void)
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}
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#endif /* CONFIG_NO_HZ */
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/* A context switch is a grace period for rcutree. */
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/* A context switch is a grace period for RCU-sched and RCU-bh. */
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static inline int rcu_blocking_is_gp(void)
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{
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return num_online_cpus() == 1;
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|
|
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@ -778,7 +778,6 @@ static void __init do_initcalls(void)
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*/
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static void __init do_basic_setup(void)
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{
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rcu_init_sched(); /* needed by module_init stage. */
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init_workqueues();
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cpuset_init_smp();
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usermodehelper_init();
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|
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@ -991,8 +991,6 @@ NORET_TYPE void do_exit(long code)
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tsk->mempolicy = NULL;
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#endif
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#ifdef CONFIG_FUTEX
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if (unlikely(!list_empty(&tsk->pi_state_list)))
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exit_pi_state_list(tsk);
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if (unlikely(current->pi_state_cache))
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kfree(current->pi_state_cache);
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#endif
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@ -570,12 +570,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
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/* Get rid of any futexes when releasing the mm */
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#ifdef CONFIG_FUTEX
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if (unlikely(tsk->robust_list))
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if (unlikely(tsk->robust_list)) {
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exit_robust_list(tsk);
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tsk->robust_list = NULL;
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}
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#ifdef CONFIG_COMPAT
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if (unlikely(tsk->compat_robust_list))
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if (unlikely(tsk->compat_robust_list)) {
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compat_exit_robust_list(tsk);
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tsk->compat_robust_list = NULL;
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}
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#endif
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if (unlikely(!list_empty(&tsk->pi_state_list)))
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exit_pi_state_list(tsk);
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#endif
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/* Get rid of any cached register state */
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@ -916,8 +916,8 @@ retry:
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hb1 = hash_futex(&key1);
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hb2 = hash_futex(&key2);
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double_lock_hb(hb1, hb2);
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retry_private:
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double_lock_hb(hb1, hb2);
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op_ret = futex_atomic_op_inuser(op, uaddr2);
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if (unlikely(op_ret < 0)) {
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@ -2117,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
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* Unqueue the futex_q and determine which it was.
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*/
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plist_del(&q->list, &q->list.plist);
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drop_futex_key_refs(&q->key);
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if (timeout && !timeout->task)
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ret = -ETIMEDOUT;
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@ -90,6 +90,8 @@ NORET_TYPE void panic(const char * fmt, ...)
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atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
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bust_spinlocks(0);
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if (!panic_blink)
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panic_blink = no_blink;
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@ -136,7 +138,6 @@ NORET_TYPE void panic(const char * fmt, ...)
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mdelay(1);
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i++;
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}
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bust_spinlocks(0);
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}
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EXPORT_SYMBOL(panic);
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@ -46,22 +46,15 @@
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#include <linux/module.h>
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#include <linux/kernel_stat.h>
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enum rcu_barrier {
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RCU_BARRIER_STD,
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RCU_BARRIER_BH,
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RCU_BARRIER_SCHED,
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};
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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static struct lock_class_key rcu_lock_key;
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struct lockdep_map rcu_lock_map =
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STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
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EXPORT_SYMBOL_GPL(rcu_lock_map);
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#endif
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static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
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static atomic_t rcu_barrier_cpu_count;
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static DEFINE_MUTEX(rcu_barrier_mutex);
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static struct completion rcu_barrier_completion;
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int rcu_scheduler_active __read_mostly;
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static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
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static struct rcu_head rcu_migrate_head[3];
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static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);
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/*
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* Awaken the corresponding synchronize_rcu() instance now that a
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* grace period has elapsed.
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@ -164,129 +157,10 @@ void synchronize_rcu_bh(void)
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}
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EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
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static void rcu_barrier_callback(struct rcu_head *notused)
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{
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if (atomic_dec_and_test(&rcu_barrier_cpu_count))
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complete(&rcu_barrier_completion);
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}
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/*
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* Called with preemption disabled, and from cross-cpu IRQ context.
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*/
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static void rcu_barrier_func(void *type)
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{
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int cpu = smp_processor_id();
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struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
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atomic_inc(&rcu_barrier_cpu_count);
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switch ((enum rcu_barrier)type) {
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case RCU_BARRIER_STD:
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call_rcu(head, rcu_barrier_callback);
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break;
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case RCU_BARRIER_BH:
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call_rcu_bh(head, rcu_barrier_callback);
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break;
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case RCU_BARRIER_SCHED:
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call_rcu_sched(head, rcu_barrier_callback);
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break;
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}
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}
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static inline void wait_migrated_callbacks(void)
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{
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wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
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smp_mb(); /* In case we didn't sleep. */
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}
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/*
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* Orchestrate the specified type of RCU barrier, waiting for all
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* RCU callbacks of the specified type to complete.
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*/
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static void _rcu_barrier(enum rcu_barrier type)
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{
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BUG_ON(in_interrupt());
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/* Take cpucontrol mutex to protect against CPU hotplug */
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mutex_lock(&rcu_barrier_mutex);
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init_completion(&rcu_barrier_completion);
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/*
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* Initialize rcu_barrier_cpu_count to 1, then invoke
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* rcu_barrier_func() on each CPU, so that each CPU also has
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* incremented rcu_barrier_cpu_count. Only then is it safe to
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* decrement rcu_barrier_cpu_count -- otherwise the first CPU
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* might complete its grace period before all of the other CPUs
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* did their increment, causing this function to return too
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* early.
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*/
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atomic_set(&rcu_barrier_cpu_count, 1);
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on_each_cpu(rcu_barrier_func, (void *)type, 1);
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if (atomic_dec_and_test(&rcu_barrier_cpu_count))
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complete(&rcu_barrier_completion);
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wait_for_completion(&rcu_barrier_completion);
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mutex_unlock(&rcu_barrier_mutex);
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wait_migrated_callbacks();
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}
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|
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/**
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* rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
|
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*/
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void rcu_barrier(void)
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{
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_rcu_barrier(RCU_BARRIER_STD);
|
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}
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EXPORT_SYMBOL_GPL(rcu_barrier);
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|
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/**
|
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* rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
|
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*/
|
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void rcu_barrier_bh(void)
|
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{
|
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_rcu_barrier(RCU_BARRIER_BH);
|
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}
|
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EXPORT_SYMBOL_GPL(rcu_barrier_bh);
|
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|
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/**
|
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* rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
|
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*/
|
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void rcu_barrier_sched(void)
|
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{
|
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_rcu_barrier(RCU_BARRIER_SCHED);
|
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}
|
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EXPORT_SYMBOL_GPL(rcu_barrier_sched);
|
||||
|
||||
static void rcu_migrate_callback(struct rcu_head *notused)
|
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{
|
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if (atomic_dec_and_test(&rcu_migrate_type_count))
|
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wake_up(&rcu_migrate_wq);
|
||||
}
|
||||
|
||||
extern int rcu_cpu_notify(struct notifier_block *self,
|
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unsigned long action, void *hcpu);
|
||||
|
||||
static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
|
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unsigned long action, void *hcpu)
|
||||
{
|
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rcu_cpu_notify(self, action, hcpu);
|
||||
if (action == CPU_DYING) {
|
||||
/*
|
||||
* preempt_disable() in on_each_cpu() prevents stop_machine(),
|
||||
* so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
|
||||
* returns, all online cpus have queued rcu_barrier_func(),
|
||||
* and the dead cpu(if it exist) queues rcu_migrate_callback()s.
|
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*
|
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* These callbacks ensure _rcu_barrier() waits for all
|
||||
* RCU callbacks of the specified type to complete.
|
||||
*/
|
||||
atomic_set(&rcu_migrate_type_count, 3);
|
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call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
|
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call_rcu_sched(rcu_migrate_head + 1, rcu_migrate_callback);
|
||||
call_rcu(rcu_migrate_head + 2, rcu_migrate_callback);
|
||||
} else if (action == CPU_DOWN_PREPARE) {
|
||||
/* Don't need to wait until next removal operation. */
|
||||
/* rcu_migrate_head is protected by cpu_add_remove_lock */
|
||||
wait_migrated_callbacks();
|
||||
}
|
||||
|
||||
return NOTIFY_OK;
|
||||
return rcu_cpu_notify(self, action, hcpu);
|
||||
}
|
||||
|
||||
void __init rcu_init(void)
|
||||
|
|
|
@ -606,8 +606,6 @@ static struct rcu_torture_ops sched_ops_sync = {
|
|||
.name = "sched_sync"
|
||||
};
|
||||
|
||||
extern int rcu_expedited_torture_stats(char *page);
|
||||
|
||||
static struct rcu_torture_ops sched_expedited_ops = {
|
||||
.init = rcu_sync_torture_init,
|
||||
.cleanup = NULL,
|
||||
|
@ -650,7 +648,7 @@ rcu_torture_writer(void *arg)
|
|||
old_rp = rcu_torture_current;
|
||||
rp->rtort_mbtest = 1;
|
||||
rcu_assign_pointer(rcu_torture_current, rp);
|
||||
smp_wmb();
|
||||
smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
|
||||
if (old_rp) {
|
||||
i = old_rp->rtort_pipe_count;
|
||||
if (i > RCU_TORTURE_PIPE_LEN)
|
||||
|
|
330
kernel/rcutree.c
330
kernel/rcutree.c
|
@ -49,13 +49,6 @@
|
|||
|
||||
#include "rcutree.h"
|
||||
|
||||
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
||||
static struct lock_class_key rcu_lock_key;
|
||||
struct lockdep_map rcu_lock_map =
|
||||
STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
|
||||
EXPORT_SYMBOL_GPL(rcu_lock_map);
|
||||
#endif
|
||||
|
||||
/* Data structures. */
|
||||
|
||||
#define RCU_STATE_INITIALIZER(name) { \
|
||||
|
@ -70,6 +63,9 @@ EXPORT_SYMBOL_GPL(rcu_lock_map);
|
|||
.gpnum = -300, \
|
||||
.completed = -300, \
|
||||
.onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
|
||||
.orphan_cbs_list = NULL, \
|
||||
.orphan_cbs_tail = &name.orphan_cbs_list, \
|
||||
.orphan_qlen = 0, \
|
||||
.fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
|
||||
.n_force_qs = 0, \
|
||||
.n_force_qs_ngp = 0, \
|
||||
|
@ -81,24 +77,16 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
|
|||
struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
|
||||
DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
|
||||
|
||||
extern long rcu_batches_completed_sched(void);
|
||||
static struct rcu_node *rcu_get_root(struct rcu_state *rsp);
|
||||
static void cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp,
|
||||
struct rcu_node *rnp, unsigned long flags);
|
||||
static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags);
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp);
|
||||
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
|
||||
static void __rcu_process_callbacks(struct rcu_state *rsp,
|
||||
struct rcu_data *rdp);
|
||||
static void __call_rcu(struct rcu_head *head,
|
||||
void (*func)(struct rcu_head *rcu),
|
||||
struct rcu_state *rsp);
|
||||
static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp);
|
||||
static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
|
||||
int preemptable);
|
||||
|
||||
#include "rcutree_plugin.h"
|
||||
/*
|
||||
* Return true if an RCU grace period is in progress. The ACCESS_ONCE()s
|
||||
* permit this function to be invoked without holding the root rcu_node
|
||||
* structure's ->lock, but of course results can be subject to change.
|
||||
*/
|
||||
static int rcu_gp_in_progress(struct rcu_state *rsp)
|
||||
{
|
||||
return ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum);
|
||||
}
|
||||
|
||||
/*
|
||||
* Note a quiescent state. Because we do not need to know
|
||||
|
@ -137,6 +125,10 @@ static int blimit = 10; /* Maximum callbacks per softirq. */
|
|||
static int qhimark = 10000; /* If this many pending, ignore blimit. */
|
||||
static int qlowmark = 100; /* Once only this many pending, use blimit. */
|
||||
|
||||
module_param(blimit, int, 0);
|
||||
module_param(qhimark, int, 0);
|
||||
module_param(qlowmark, int, 0);
|
||||
|
||||
static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
|
||||
static int rcu_pending(int cpu);
|
||||
|
||||
|
@ -173,9 +165,7 @@ cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
|
|||
static int
|
||||
cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
|
||||
{
|
||||
/* ACCESS_ONCE() because we are accessing outside of lock. */
|
||||
return *rdp->nxttail[RCU_DONE_TAIL] &&
|
||||
ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum);
|
||||
return *rdp->nxttail[RCU_DONE_TAIL] && !rcu_gp_in_progress(rsp);
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -369,7 +359,7 @@ static long dyntick_recall_completed(struct rcu_state *rsp)
|
|||
/*
|
||||
* Snapshot the specified CPU's dynticks counter so that we can later
|
||||
* credit them with an implicit quiescent state. Return 1 if this CPU
|
||||
* is already in a quiescent state courtesy of dynticks idle mode.
|
||||
* is in dynticks idle mode, which is an extended quiescent state.
|
||||
*/
|
||||
static int dyntick_save_progress_counter(struct rcu_data *rdp)
|
||||
{
|
||||
|
@ -475,30 +465,34 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
|
|||
long delta;
|
||||
unsigned long flags;
|
||||
struct rcu_node *rnp = rcu_get_root(rsp);
|
||||
struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
|
||||
struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
|
||||
|
||||
/* Only let one CPU complain about others per time interval. */
|
||||
|
||||
spin_lock_irqsave(&rnp->lock, flags);
|
||||
delta = jiffies - rsp->jiffies_stall;
|
||||
if (delta < RCU_STALL_RAT_DELAY || rsp->gpnum == rsp->completed) {
|
||||
if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
|
||||
spin_unlock_irqrestore(&rnp->lock, flags);
|
||||
return;
|
||||
}
|
||||
rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
|
||||
|
||||
/*
|
||||
* Now rat on any tasks that got kicked up to the root rcu_node
|
||||
* due to CPU offlining.
|
||||
*/
|
||||
rcu_print_task_stall(rnp);
|
||||
spin_unlock_irqrestore(&rnp->lock, flags);
|
||||
|
||||
/* OK, time to rat on our buddy... */
|
||||
|
||||
printk(KERN_ERR "INFO: RCU detected CPU stalls:");
|
||||
for (; rnp_cur < rnp_end; rnp_cur++) {
|
||||
rcu_for_each_leaf_node(rsp, rnp) {
|
||||
rcu_print_task_stall(rnp);
|
||||
if (rnp_cur->qsmask == 0)
|
||||
if (rnp->qsmask == 0)
|
||||
continue;
|
||||
for (cpu = 0; cpu <= rnp_cur->grphi - rnp_cur->grplo; cpu++)
|
||||
if (rnp_cur->qsmask & (1UL << cpu))
|
||||
printk(" %d", rnp_cur->grplo + cpu);
|
||||
for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
|
||||
if (rnp->qsmask & (1UL << cpu))
|
||||
printk(" %d", rnp->grplo + cpu);
|
||||
}
|
||||
printk(" (detected by %d, t=%ld jiffies)\n",
|
||||
smp_processor_id(), (long)(jiffies - rsp->gp_start));
|
||||
|
@ -537,8 +531,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
|
|||
/* We haven't checked in, so go dump stack. */
|
||||
print_cpu_stall(rsp);
|
||||
|
||||
} else if (rsp->gpnum != rsp->completed &&
|
||||
delta >= RCU_STALL_RAT_DELAY) {
|
||||
} else if (rcu_gp_in_progress(rsp) && delta >= RCU_STALL_RAT_DELAY) {
|
||||
|
||||
/* They had two time units to dump stack, so complain. */
|
||||
print_other_cpu_stall(rsp);
|
||||
|
@ -617,9 +610,15 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
|
|||
note_new_gpnum(rsp, rdp);
|
||||
|
||||
/*
|
||||
* Because we are first, we know that all our callbacks will
|
||||
* be covered by this upcoming grace period, even the ones
|
||||
* that were registered arbitrarily recently.
|
||||
* Because this CPU just now started the new grace period, we know
|
||||
* that all of its callbacks will be covered by this upcoming grace
|
||||
* period, even the ones that were registered arbitrarily recently.
|
||||
* Therefore, advance all outstanding callbacks to RCU_WAIT_TAIL.
|
||||
*
|
||||
* Other CPUs cannot be sure exactly when the grace period started.
|
||||
* Therefore, their recently registered callbacks must pass through
|
||||
* an additional RCU_NEXT_READY stage, so that they will be handled
|
||||
* by the next RCU grace period.
|
||||
*/
|
||||
rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
|
||||
rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
|
||||
|
@ -657,7 +656,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
|
|||
* one corresponding to this CPU, due to the fact that we have
|
||||
* irqs disabled.
|
||||
*/
|
||||
for (rnp = &rsp->node[0]; rnp < &rsp->node[NUM_RCU_NODES]; rnp++) {
|
||||
rcu_for_each_node_breadth_first(rsp, rnp) {
|
||||
spin_lock(&rnp->lock); /* irqs already disabled. */
|
||||
rcu_preempt_check_blocked_tasks(rnp);
|
||||
rnp->qsmask = rnp->qsmaskinit;
|
||||
|
@ -703,9 +702,9 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
|
|||
* hold rnp->lock, as required by rcu_start_gp(), which will release it.
|
||||
*/
|
||||
static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
|
||||
__releases(rnp->lock)
|
||||
__releases(rcu_get_root(rsp)->lock)
|
||||
{
|
||||
WARN_ON_ONCE(rsp->completed == rsp->gpnum);
|
||||
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
|
||||
rsp->completed = rsp->gpnum;
|
||||
rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
|
||||
rcu_start_gp(rsp, flags); /* releases root node's rnp->lock. */
|
||||
|
@ -841,18 +840,64 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
|
|||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
|
||||
/*
|
||||
* Move a dying CPU's RCU callbacks to the ->orphan_cbs_list for the
|
||||
* specified flavor of RCU. The callbacks will be adopted by the next
|
||||
* _rcu_barrier() invocation or by the CPU_DEAD notifier, whichever
|
||||
* comes first. Because this is invoked from the CPU_DYING notifier,
|
||||
* irqs are already disabled.
|
||||
*/
|
||||
static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
|
||||
{
|
||||
int i;
|
||||
struct rcu_data *rdp = rsp->rda[smp_processor_id()];
|
||||
|
||||
if (rdp->nxtlist == NULL)
|
||||
return; /* irqs disabled, so comparison is stable. */
|
||||
spin_lock(&rsp->onofflock); /* irqs already disabled. */
|
||||
*rsp->orphan_cbs_tail = rdp->nxtlist;
|
||||
rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];
|
||||
rdp->nxtlist = NULL;
|
||||
for (i = 0; i < RCU_NEXT_SIZE; i++)
|
||||
rdp->nxttail[i] = &rdp->nxtlist;
|
||||
rsp->orphan_qlen += rdp->qlen;
|
||||
rdp->qlen = 0;
|
||||
spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
|
||||
}
|
||||
|
||||
/*
|
||||
* Adopt previously orphaned RCU callbacks.
|
||||
*/
|
||||
static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
|
||||
{
|
||||
unsigned long flags;
|
||||
struct rcu_data *rdp;
|
||||
|
||||
spin_lock_irqsave(&rsp->onofflock, flags);
|
||||
rdp = rsp->rda[smp_processor_id()];
|
||||
if (rsp->orphan_cbs_list == NULL) {
|
||||
spin_unlock_irqrestore(&rsp->onofflock, flags);
|
||||
return;
|
||||
}
|
||||
*rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
|
||||
rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_tail;
|
||||
rdp->qlen += rsp->orphan_qlen;
|
||||
rsp->orphan_cbs_list = NULL;
|
||||
rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
|
||||
rsp->orphan_qlen = 0;
|
||||
spin_unlock_irqrestore(&rsp->onofflock, flags);
|
||||
}
|
||||
|
||||
/*
|
||||
* Remove the outgoing CPU from the bitmasks in the rcu_node hierarchy
|
||||
* and move all callbacks from the outgoing CPU to the current one.
|
||||
*/
|
||||
static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
|
||||
{
|
||||
int i;
|
||||
unsigned long flags;
|
||||
long lastcomp;
|
||||
unsigned long mask;
|
||||
struct rcu_data *rdp = rsp->rda[cpu];
|
||||
struct rcu_data *rdp_me;
|
||||
struct rcu_node *rnp;
|
||||
|
||||
/* Exclude any attempts to start a new grace period. */
|
||||
|
@ -875,32 +920,9 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
|
|||
} while (rnp != NULL);
|
||||
lastcomp = rsp->completed;
|
||||
|
||||
spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
|
||||
spin_unlock_irqrestore(&rsp->onofflock, flags);
|
||||
|
||||
/*
|
||||
* Move callbacks from the outgoing CPU to the running CPU.
|
||||
* Note that the outgoing CPU is now quiscent, so it is now
|
||||
* (uncharacteristically) safe to access its rcu_data structure.
|
||||
* Note also that we must carefully retain the order of the
|
||||
* outgoing CPU's callbacks in order for rcu_barrier() to work
|
||||
* correctly. Finally, note that we start all the callbacks
|
||||
* afresh, even those that have passed through a grace period
|
||||
* and are therefore ready to invoke. The theory is that hotplug
|
||||
* events are rare, and that if they are frequent enough to
|
||||
* indefinitely delay callbacks, you have far worse things to
|
||||
* be worrying about.
|
||||
*/
|
||||
rdp_me = rsp->rda[smp_processor_id()];
|
||||
if (rdp->nxtlist != NULL) {
|
||||
*rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxtlist;
|
||||
rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
|
||||
rdp->nxtlist = NULL;
|
||||
for (i = 0; i < RCU_NEXT_SIZE; i++)
|
||||
rdp->nxttail[i] = &rdp->nxtlist;
|
||||
rdp_me->qlen += rdp->qlen;
|
||||
rdp->qlen = 0;
|
||||
}
|
||||
local_irq_restore(flags);
|
||||
rcu_adopt_orphan_cbs(rsp);
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -918,6 +940,14 @@ static void rcu_offline_cpu(int cpu)
|
|||
|
||||
#else /* #ifdef CONFIG_HOTPLUG_CPU */
|
||||
|
||||
static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
|
||||
{
|
||||
}
|
||||
|
||||
static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
|
||||
{
|
||||
}
|
||||
|
||||
static void rcu_offline_cpu(int cpu)
|
||||
{
|
||||
}
|
||||
|
@ -1050,33 +1080,32 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
|
|||
int cpu;
|
||||
unsigned long flags;
|
||||
unsigned long mask;
|
||||
struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
|
||||
struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
|
||||
struct rcu_node *rnp;
|
||||
|
||||
for (; rnp_cur < rnp_end; rnp_cur++) {
|
||||
rcu_for_each_leaf_node(rsp, rnp) {
|
||||
mask = 0;
|
||||
spin_lock_irqsave(&rnp_cur->lock, flags);
|
||||
spin_lock_irqsave(&rnp->lock, flags);
|
||||
if (rsp->completed != lastcomp) {
|
||||
spin_unlock_irqrestore(&rnp_cur->lock, flags);
|
||||
spin_unlock_irqrestore(&rnp->lock, flags);
|
||||
return 1;
|
||||
}
|
||||
if (rnp_cur->qsmask == 0) {
|
||||
spin_unlock_irqrestore(&rnp_cur->lock, flags);
|
||||
if (rnp->qsmask == 0) {
|
||||
spin_unlock_irqrestore(&rnp->lock, flags);
|
||||
continue;
|
||||
}
|
||||
cpu = rnp_cur->grplo;
|
||||
cpu = rnp->grplo;
|
||||
bit = 1;
|
||||
for (; cpu <= rnp_cur->grphi; cpu++, bit <<= 1) {
|
||||
if ((rnp_cur->qsmask & bit) != 0 && f(rsp->rda[cpu]))
|
||||
for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
|
||||
if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
|
||||
mask |= bit;
|
||||
}
|
||||
if (mask != 0 && rsp->completed == lastcomp) {
|
||||
|
||||
/* cpu_quiet_msk() releases rnp_cur->lock. */
|
||||
cpu_quiet_msk(mask, rsp, rnp_cur, flags);
|
||||
/* cpu_quiet_msk() releases rnp->lock. */
|
||||
cpu_quiet_msk(mask, rsp, rnp, flags);
|
||||
continue;
|
||||
}
|
||||
spin_unlock_irqrestore(&rnp_cur->lock, flags);
|
||||
spin_unlock_irqrestore(&rnp->lock, flags);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
@ -1092,7 +1121,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
|
|||
struct rcu_node *rnp = rcu_get_root(rsp);
|
||||
u8 signaled;
|
||||
|
||||
if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum))
|
||||
if (!rcu_gp_in_progress(rsp))
|
||||
return; /* No grace period in progress, nothing to force. */
|
||||
if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
|
||||
rsp->n_force_qs_lh++; /* Inexact, can lose counts. Tough! */
|
||||
|
@ -1251,7 +1280,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
|
|||
rdp->nxttail[RCU_NEXT_TAIL] = &head->next;
|
||||
|
||||
/* Start a new grace period if one not already started. */
|
||||
if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum)) {
|
||||
if (!rcu_gp_in_progress(rsp)) {
|
||||
unsigned long nestflag;
|
||||
struct rcu_node *rnp_root = rcu_get_root(rsp);
|
||||
|
||||
|
@ -1331,7 +1360,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
|
|||
}
|
||||
|
||||
/* Has an RCU GP gone long enough to send resched IPIs &c? */
|
||||
if (ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum) &&
|
||||
if (rcu_gp_in_progress(rsp) &&
|
||||
((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
|
||||
rdp->n_rp_need_fqs++;
|
||||
return 1;
|
||||
|
@ -1368,6 +1397,82 @@ int rcu_needs_cpu(int cpu)
|
|||
rcu_preempt_needs_cpu(cpu);
|
||||
}
|
||||
|
||||
static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
|
||||
static atomic_t rcu_barrier_cpu_count;
|
||||
static DEFINE_MUTEX(rcu_barrier_mutex);
|
||||
static struct completion rcu_barrier_completion;
|
||||
|
||||
static void rcu_barrier_callback(struct rcu_head *notused)
|
||||
{
|
||||
if (atomic_dec_and_test(&rcu_barrier_cpu_count))
|
||||
complete(&rcu_barrier_completion);
|
||||
}
|
||||
|
||||
/*
|
||||
* Called with preemption disabled, and from cross-cpu IRQ context.
|
||||
*/
|
||||
static void rcu_barrier_func(void *type)
|
||||
{
|
||||
int cpu = smp_processor_id();
|
||||
struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
|
||||
void (*call_rcu_func)(struct rcu_head *head,
|
||||
void (*func)(struct rcu_head *head));
|
||||
|
||||
atomic_inc(&rcu_barrier_cpu_count);
|
||||
call_rcu_func = type;
|
||||
call_rcu_func(head, rcu_barrier_callback);
|
||||
}
|
||||
|
||||
/*
|
||||
* Orchestrate the specified type of RCU barrier, waiting for all
|
||||
* RCU callbacks of the specified type to complete.
|
||||
*/
|
||||
static void _rcu_barrier(struct rcu_state *rsp,
|
||||
void (*call_rcu_func)(struct rcu_head *head,
|
||||
void (*func)(struct rcu_head *head)))
|
||||
{
|
||||
BUG_ON(in_interrupt());
|
||||
/* Take mutex to serialize concurrent rcu_barrier() requests. */
|
||||
mutex_lock(&rcu_barrier_mutex);
|
||||
init_completion(&rcu_barrier_completion);
|
||||
/*
|
||||
* Initialize rcu_barrier_cpu_count to 1, then invoke
|
||||
* rcu_barrier_func() on each CPU, so that each CPU also has
|
||||
* incremented rcu_barrier_cpu_count. Only then is it safe to
|
||||
* decrement rcu_barrier_cpu_count -- otherwise the first CPU
|
||||
* might complete its grace period before all of the other CPUs
|
||||
* did their increment, causing this function to return too
|
||||
* early.
|
||||
*/
|
||||
atomic_set(&rcu_barrier_cpu_count, 1);
|
||||
preempt_disable(); /* stop CPU_DYING from filling orphan_cbs_list */
|
||||
rcu_adopt_orphan_cbs(rsp);
|
||||
on_each_cpu(rcu_barrier_func, (void *)call_rcu_func, 1);
|
||||
preempt_enable(); /* CPU_DYING can again fill orphan_cbs_list */
|
||||
if (atomic_dec_and_test(&rcu_barrier_cpu_count))
|
||||
complete(&rcu_barrier_completion);
|
||||
wait_for_completion(&rcu_barrier_completion);
|
||||
mutex_unlock(&rcu_barrier_mutex);
|
||||
}
|
||||
|
||||
/**
|
||||
* rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
|
||||
*/
|
||||
void rcu_barrier_bh(void)
|
||||
{
|
||||
_rcu_barrier(&rcu_bh_state, call_rcu_bh);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(rcu_barrier_bh);
|
||||
|
||||
/**
|
||||
* rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
|
||||
*/
|
||||
void rcu_barrier_sched(void)
|
||||
{
|
||||
_rcu_barrier(&rcu_sched_state, call_rcu_sched);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(rcu_barrier_sched);
|
||||
|
||||
/*
|
||||
* Do boot-time initialization of a CPU's per-CPU RCU data.
|
||||
*/
|
||||
|
@ -1464,6 +1569,22 @@ int __cpuinit rcu_cpu_notify(struct notifier_block *self,
|
|||
case CPU_UP_PREPARE_FROZEN:
|
||||
rcu_online_cpu(cpu);
|
||||
break;
|
||||
case CPU_DYING:
|
||||
case CPU_DYING_FROZEN:
|
||||
/*
|
||||
* preempt_disable() in _rcu_barrier() prevents stop_machine(),
|
||||
* so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
|
||||
* returns, all online cpus have queued rcu_barrier_func().
|
||||
* The dying CPU clears its cpu_online_mask bit and
|
||||
* moves all of its RCU callbacks to ->orphan_cbs_list
|
||||
* in the context of stop_machine(), so subsequent calls
|
||||
* to _rcu_barrier() will adopt these callbacks and only
|
||||
* then queue rcu_barrier_func() on all remaining CPUs.
|
||||
*/
|
||||
rcu_send_cbs_to_orphanage(&rcu_bh_state);
|
||||
rcu_send_cbs_to_orphanage(&rcu_sched_state);
|
||||
rcu_preempt_send_cbs_to_orphanage();
|
||||
break;
|
||||
case CPU_DEAD:
|
||||
case CPU_DEAD_FROZEN:
|
||||
case CPU_UP_CANCELED:
|
||||
|
@ -1526,7 +1647,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
|
|||
cpustride *= rsp->levelspread[i];
|
||||
rnp = rsp->level[i];
|
||||
for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
|
||||
spin_lock_init(&rnp->lock);
|
||||
if (rnp != rcu_get_root(rsp))
|
||||
spin_lock_init(&rnp->lock);
|
||||
rnp->gpnum = 0;
|
||||
rnp->qsmask = 0;
|
||||
rnp->qsmaskinit = 0;
|
||||
|
@ -1549,6 +1671,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
|
|||
INIT_LIST_HEAD(&rnp->blocked_tasks[1]);
|
||||
}
|
||||
}
|
||||
spin_lock_init(&rcu_get_root(rsp)->lock);
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -1558,6 +1681,10 @@ static void __init rcu_init_one(struct rcu_state *rsp)
|
|||
*/
|
||||
#define RCU_INIT_FLAVOR(rsp, rcu_data) \
|
||||
do { \
|
||||
int i; \
|
||||
int j; \
|
||||
struct rcu_node *rnp; \
|
||||
\
|
||||
rcu_init_one(rsp); \
|
||||
rnp = (rsp)->level[NUM_RCU_LVLS - 1]; \
|
||||
j = 0; \
|
||||
|
@ -1570,31 +1697,8 @@ do { \
|
|||
} \
|
||||
} while (0)
|
||||
|
||||
#ifdef CONFIG_TREE_PREEMPT_RCU
|
||||
|
||||
void __init __rcu_init_preempt(void)
|
||||
{
|
||||
int i; /* All used by RCU_INIT_FLAVOR(). */
|
||||
int j;
|
||||
struct rcu_node *rnp;
|
||||
|
||||
RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
|
||||
}
|
||||
|
||||
#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
|
||||
|
||||
void __init __rcu_init_preempt(void)
|
||||
{
|
||||
}
|
||||
|
||||
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
|
||||
|
||||
void __init __rcu_init(void)
|
||||
{
|
||||
int i; /* All used by RCU_INIT_FLAVOR(). */
|
||||
int j;
|
||||
struct rcu_node *rnp;
|
||||
|
||||
rcu_bootup_announce();
|
||||
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
|
||||
printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
|
||||
|
@ -1605,6 +1709,4 @@ void __init __rcu_init(void)
|
|||
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
|
||||
}
|
||||
|
||||
module_param(blimit, int, 0);
|
||||
module_param(qhimark, int, 0);
|
||||
module_param(qlowmark, int, 0);
|
||||
#include "rcutree_plugin.h"
|
||||
|
|
|
@ -48,14 +48,14 @@
|
|||
#elif NR_CPUS <= RCU_FANOUT_SQ
|
||||
# define NUM_RCU_LVLS 2
|
||||
# define NUM_RCU_LVL_0 1
|
||||
# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)
|
||||
# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
|
||||
# define NUM_RCU_LVL_2 (NR_CPUS)
|
||||
# define NUM_RCU_LVL_3 0
|
||||
#elif NR_CPUS <= RCU_FANOUT_CUBE
|
||||
# define NUM_RCU_LVLS 3
|
||||
# define NUM_RCU_LVL_0 1
|
||||
# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)
|
||||
# define NUM_RCU_LVL_2 (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))
|
||||
# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ)
|
||||
# define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
|
||||
# define NUM_RCU_LVL_3 NR_CPUS
|
||||
#else
|
||||
# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
|
||||
|
@ -79,15 +79,21 @@ struct rcu_dynticks {
|
|||
* Definition for node within the RCU grace-period-detection hierarchy.
|
||||
*/
|
||||
struct rcu_node {
|
||||
spinlock_t lock;
|
||||
spinlock_t lock; /* Root rcu_node's lock protects some */
|
||||
/* rcu_state fields as well as following. */
|
||||
long gpnum; /* Current grace period for this node. */
|
||||
/* This will either be equal to or one */
|
||||
/* behind the root rcu_node's gpnum. */
|
||||
unsigned long qsmask; /* CPUs or groups that need to switch in */
|
||||
/* order for current grace period to proceed.*/
|
||||
/* In leaf rcu_node, each bit corresponds to */
|
||||
/* an rcu_data structure, otherwise, each */
|
||||
/* bit corresponds to a child rcu_node */
|
||||
/* structure. */
|
||||
unsigned long qsmaskinit;
|
||||
/* Per-GP initialization for qsmask. */
|
||||
unsigned long grpmask; /* Mask to apply to parent qsmask. */
|
||||
/* Only one bit will be set in this mask. */
|
||||
int grplo; /* lowest-numbered CPU or group here. */
|
||||
int grphi; /* highest-numbered CPU or group here. */
|
||||
u8 grpnum; /* CPU/group number for next level up. */
|
||||
|
@ -95,8 +101,23 @@ struct rcu_node {
|
|||
struct rcu_node *parent;
|
||||
struct list_head blocked_tasks[2];
|
||||
/* Tasks blocked in RCU read-side critsect. */
|
||||
/* Grace period number (->gpnum) x blocked */
|
||||
/* by tasks on the (x & 0x1) element of the */
|
||||
/* blocked_tasks[] array. */
|
||||
} ____cacheline_internodealigned_in_smp;
|
||||
|
||||
/*
|
||||
* Do a full breadth-first scan of the rcu_node structures for the
|
||||
* specified rcu_state structure.
|
||||
*/
|
||||
#define rcu_for_each_node_breadth_first(rsp, rnp) \
|
||||
for ((rnp) = &(rsp)->node[0]; \
|
||||
(rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
|
||||
|
||||
#define rcu_for_each_leaf_node(rsp, rnp) \
|
||||
for ((rnp) = (rsp)->level[NUM_RCU_LVLS - 1]; \
|
||||
(rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
|
||||
|
||||
/* Index values for nxttail array in struct rcu_data. */
|
||||
#define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */
|
||||
#define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */
|
||||
|
@ -126,19 +147,22 @@ struct rcu_data {
|
|||
* Any of the partitions might be empty, in which case the
|
||||
* pointer to that partition will be equal to the pointer for
|
||||
* the following partition. When the list is empty, all of
|
||||
* the nxttail elements point to nxtlist, which is NULL.
|
||||
* the nxttail elements point to the ->nxtlist pointer itself,
|
||||
* which in that case is NULL.
|
||||
*
|
||||
* [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):
|
||||
* Entries that might have arrived after current GP ended
|
||||
* [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
|
||||
* Entries known to have arrived before current GP ended
|
||||
* [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
|
||||
* Entries that batch # <= ->completed - 1: waiting for current GP
|
||||
* [nxtlist, *nxttail[RCU_DONE_TAIL]):
|
||||
* Entries that batch # <= ->completed
|
||||
* The grace period for these entries has completed, and
|
||||
* the other grace-period-completed entries may be moved
|
||||
* here temporarily in rcu_process_callbacks().
|
||||
* [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
|
||||
* Entries that batch # <= ->completed - 1: waiting for current GP
|
||||
* [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
|
||||
* Entries known to have arrived before current GP ended
|
||||
* [*nxttail[RCU_NEXT_READY_TAIL], *nxttail[RCU_NEXT_TAIL]):
|
||||
* Entries that might have arrived after current GP ended
|
||||
* Note that the value of *nxttail[RCU_NEXT_TAIL] will
|
||||
* always be NULL, as this is the end of the list.
|
||||
*/
|
||||
struct rcu_head *nxtlist;
|
||||
struct rcu_head **nxttail[RCU_NEXT_SIZE];
|
||||
|
@ -216,8 +240,19 @@ struct rcu_state {
|
|||
/* Force QS state. */
|
||||
long gpnum; /* Current gp number. */
|
||||
long completed; /* # of last completed gp. */
|
||||
|
||||
/* End of fields guarded by root rcu_node's lock. */
|
||||
|
||||
spinlock_t onofflock; /* exclude on/offline and */
|
||||
/* starting new GP. */
|
||||
/* starting new GP. Also */
|
||||
/* protects the following */
|
||||
/* orphan_cbs fields. */
|
||||
struct rcu_head *orphan_cbs_list; /* list of rcu_head structs */
|
||||
/* orphaned by all CPUs in */
|
||||
/* a given leaf rcu_node */
|
||||
/* going offline. */
|
||||
struct rcu_head **orphan_cbs_tail; /* And tail pointer. */
|
||||
long orphan_qlen; /* Number of orphaned cbs. */
|
||||
spinlock_t fqslock; /* Only one task forcing */
|
||||
/* quiescent states. */
|
||||
unsigned long jiffies_force_qs; /* Time at which to invoke */
|
||||
|
@ -255,5 +290,30 @@ extern struct rcu_state rcu_preempt_state;
|
|||
DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
|
||||
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
|
||||
|
||||
#endif /* #ifdef RCU_TREE_NONCORE */
|
||||
#else /* #ifdef RCU_TREE_NONCORE */
|
||||
|
||||
/* Forward declarations for rcutree_plugin.h */
|
||||
static inline void rcu_bootup_announce(void);
|
||||
long rcu_batches_completed(void);
|
||||
static void rcu_preempt_note_context_switch(int cpu);
|
||||
static int rcu_preempted_readers(struct rcu_node *rnp);
|
||||
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
|
||||
static void rcu_print_task_stall(struct rcu_node *rnp);
|
||||
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
|
||||
static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
|
||||
struct rcu_node *rnp,
|
||||
struct rcu_data *rdp);
|
||||
static void rcu_preempt_offline_cpu(int cpu);
|
||||
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
|
||||
static void rcu_preempt_check_callbacks(int cpu);
|
||||
static void rcu_preempt_process_callbacks(void);
|
||||
void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
|
||||
static int rcu_preempt_pending(int cpu);
|
||||
static int rcu_preempt_needs_cpu(int cpu);
|
||||
static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
|
||||
static void rcu_preempt_send_cbs_to_orphanage(void);
|
||||
static void __init __rcu_init_preempt(void);
|
||||
|
||||
#endif /* #else #ifdef RCU_TREE_NONCORE */
|
||||
|
|
|
@ -150,6 +150,16 @@ void __rcu_read_lock(void)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(__rcu_read_lock);
|
||||
|
||||
/*
|
||||
* Check for preempted RCU readers blocking the current grace period
|
||||
* for the specified rcu_node structure. If the caller needs a reliable
|
||||
* answer, it must hold the rcu_node's ->lock.
|
||||
*/
|
||||
static int rcu_preempted_readers(struct rcu_node *rnp)
|
||||
{
|
||||
return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
|
||||
}
|
||||
|
||||
static void rcu_read_unlock_special(struct task_struct *t)
|
||||
{
|
||||
int empty;
|
||||
|
@ -196,7 +206,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
|
|||
break;
|
||||
spin_unlock(&rnp->lock); /* irqs remain disabled. */
|
||||
}
|
||||
empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
|
||||
empty = !rcu_preempted_readers(rnp);
|
||||
list_del_init(&t->rcu_node_entry);
|
||||
t->rcu_blocked_node = NULL;
|
||||
|
||||
|
@ -207,7 +217,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
|
|||
* drop rnp->lock and restore irq.
|
||||
*/
|
||||
if (!empty && rnp->qsmask == 0 &&
|
||||
list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) {
|
||||
!rcu_preempted_readers(rnp)) {
|
||||
struct rcu_node *rnp_p;
|
||||
|
||||
if (rnp->parent == NULL) {
|
||||
|
@ -257,12 +267,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
|
|||
{
|
||||
unsigned long flags;
|
||||
struct list_head *lp;
|
||||
int phase = rnp->gpnum & 0x1;
|
||||
int phase;
|
||||
struct task_struct *t;
|
||||
|
||||
if (!list_empty(&rnp->blocked_tasks[phase])) {
|
||||
if (rcu_preempted_readers(rnp)) {
|
||||
spin_lock_irqsave(&rnp->lock, flags);
|
||||
phase = rnp->gpnum & 0x1; /* re-read under lock. */
|
||||
phase = rnp->gpnum & 0x1;
|
||||
lp = &rnp->blocked_tasks[phase];
|
||||
list_for_each_entry(t, lp, rcu_node_entry)
|
||||
printk(" P%d", t->pid);
|
||||
|
@ -281,20 +291,10 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
|
|||
*/
|
||||
static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
|
||||
{
|
||||
WARN_ON_ONCE(!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]));
|
||||
WARN_ON_ONCE(rcu_preempted_readers(rnp));
|
||||
WARN_ON_ONCE(rnp->qsmask);
|
||||
}
|
||||
|
||||
/*
|
||||
* Check for preempted RCU readers for the specified rcu_node structure.
|
||||
* If the caller needs a reliable answer, it must hold the rcu_node's
|
||||
* >lock.
|
||||
*/
|
||||
static int rcu_preempted_readers(struct rcu_node *rnp)
|
||||
{
|
||||
return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
|
||||
/*
|
||||
|
@ -410,6 +410,15 @@ static int rcu_preempt_needs_cpu(int cpu)
|
|||
return !!per_cpu(rcu_preempt_data, cpu).nxtlist;
|
||||
}
|
||||
|
||||
/**
|
||||
* rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
|
||||
*/
|
||||
void rcu_barrier(void)
|
||||
{
|
||||
_rcu_barrier(&rcu_preempt_state, call_rcu);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(rcu_barrier);
|
||||
|
||||
/*
|
||||
* Initialize preemptable RCU's per-CPU data.
|
||||
*/
|
||||
|
@ -418,6 +427,22 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
|
|||
rcu_init_percpu_data(cpu, &rcu_preempt_state, 1);
|
||||
}
|
||||
|
||||
/*
|
||||
* Move preemptable RCU's callbacks to ->orphan_cbs_list.
|
||||
*/
|
||||
static void rcu_preempt_send_cbs_to_orphanage(void)
|
||||
{
|
||||
rcu_send_cbs_to_orphanage(&rcu_preempt_state);
|
||||
}
|
||||
|
||||
/*
|
||||
* Initialize preemptable RCU's state structures.
|
||||
*/
|
||||
static void __init __rcu_init_preempt(void)
|
||||
{
|
||||
RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
|
||||
}
|
||||
|
||||
/*
|
||||
* Check for a task exiting while in a preemptable-RCU read-side
|
||||
* critical section, clean up if so. No need to issue warnings,
|
||||
|
@ -461,6 +486,15 @@ static void rcu_preempt_note_context_switch(int cpu)
|
|||
{
|
||||
}
|
||||
|
||||
/*
|
||||
* Because preemptable RCU does not exist, there are never any preempted
|
||||
* RCU readers.
|
||||
*/
|
||||
static int rcu_preempted_readers(struct rcu_node *rnp)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
|
||||
|
||||
/*
|
||||
|
@ -483,15 +517,6 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
|
|||
WARN_ON_ONCE(rnp->qsmask);
|
||||
}
|
||||
|
||||
/*
|
||||
* Because preemptable RCU does not exist, there are never any preempted
|
||||
* RCU readers.
|
||||
*/
|
||||
static int rcu_preempted_readers(struct rcu_node *rnp)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
|
||||
/*
|
||||
|
@ -518,7 +543,7 @@ static void rcu_preempt_offline_cpu(int cpu)
|
|||
* Because preemptable RCU does not exist, it never has any callbacks
|
||||
* to check.
|
||||
*/
|
||||
void rcu_preempt_check_callbacks(int cpu)
|
||||
static void rcu_preempt_check_callbacks(int cpu)
|
||||
{
|
||||
}
|
||||
|
||||
|
@ -526,7 +551,7 @@ void rcu_preempt_check_callbacks(int cpu)
|
|||
* Because preemptable RCU does not exist, it never has any callbacks
|
||||
* to process.
|
||||
*/
|
||||
void rcu_preempt_process_callbacks(void)
|
||||
static void rcu_preempt_process_callbacks(void)
|
||||
{
|
||||
}
|
||||
|
||||
|
@ -555,6 +580,16 @@ static int rcu_preempt_needs_cpu(int cpu)
|
|||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Because preemptable RCU does not exist, rcu_barrier() is just
|
||||
* another name for rcu_barrier_sched().
|
||||
*/
|
||||
void rcu_barrier(void)
|
||||
{
|
||||
rcu_barrier_sched();
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(rcu_barrier);
|
||||
|
||||
/*
|
||||
* Because preemptable RCU does not exist, there is no per-CPU
|
||||
* data to initialize.
|
||||
|
@ -563,4 +598,18 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
|
|||
{
|
||||
}
|
||||
|
||||
/*
|
||||
* Because there is no preemptable RCU, there are no callbacks to move.
|
||||
*/
|
||||
static void rcu_preempt_send_cbs_to_orphanage(void)
|
||||
{
|
||||
}
|
||||
|
||||
/*
|
||||
* Because preemptable RCU does not exist, it need not be initialized.
|
||||
*/
|
||||
static void __init __rcu_init_preempt(void)
|
||||
{
|
||||
}
|
||||
|
||||
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
|
||||
|
|
|
@ -159,13 +159,13 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
|
|||
struct rcu_node *rnp;
|
||||
|
||||
seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
|
||||
"nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
|
||||
"nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
|
||||
rsp->completed, rsp->gpnum, rsp->signaled,
|
||||
(long)(rsp->jiffies_force_qs - jiffies),
|
||||
(int)(jiffies & 0xffff),
|
||||
rsp->n_force_qs, rsp->n_force_qs_ngp,
|
||||
rsp->n_force_qs - rsp->n_force_qs_ngp,
|
||||
rsp->n_force_qs_lh);
|
||||
rsp->n_force_qs_lh, rsp->orphan_qlen);
|
||||
for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
|
||||
if (rnp->level != level) {
|
||||
seq_puts(m, "\n");
|
||||
|
|
Loading…
Reference in a new issue