Commit f579bbcd authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'core-fixes-for-linus' of...

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
parents e80fb7e5 da085681
......@@ -33,8 +33,8 @@
#define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITS | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITS | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAIT_REQUEUE_PI_PRIVATE (FUTEX_WAIT_REQUEUE_PI | \
FUTEX_PRIVATE_FLAG)
#define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \
......
......@@ -129,12 +129,6 @@ static inline void rcu_read_lock(void)
rcu_read_acquire();
}
/**
* rcu_read_unlock - marks the end of an RCU read-side critical section.
*
* See rcu_read_lock() for more information.
*/
/*
* So where is rcu_write_lock()? It does not exist, as there is no
* way for writers to lock out RCU readers. This is a feature, not
......@@ -144,6 +138,12 @@ static inline void rcu_read_lock(void)
* used as well. RCU does not care how the writers keep out of each
* others' way, as long as they do so.
*/
/**
* rcu_read_unlock - marks the end of an RCU read-side critical section.
*
* See rcu_read_lock() for more information.
*/
static inline void rcu_read_unlock(void)
{
rcu_read_release();
......@@ -196,6 +196,8 @@ static inline void rcu_read_lock_sched(void)
__acquire(RCU_SCHED);
rcu_read_acquire();
}
/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
static inline notrace void rcu_read_lock_sched_notrace(void)
{
preempt_disable_notrace();
......@@ -213,6 +215,8 @@ static inline void rcu_read_unlock_sched(void)
__release(RCU_SCHED);
preempt_enable();
}
/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
static inline notrace void rcu_read_unlock_sched_notrace(void)
{
__release(RCU_SCHED);
......
......@@ -30,10 +30,14 @@
#ifndef __LINUX_RCUTREE_H
#define __LINUX_RCUTREE_H
struct notifier_block;
extern void rcu_sched_qs(int cpu);
extern void rcu_bh_qs(int cpu);
extern int rcu_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu);
extern int rcu_needs_cpu(int cpu);
extern int rcu_expedited_torture_stats(char *page);
#ifdef CONFIG_TREE_PREEMPT_RCU
......@@ -85,16 +89,11 @@ static inline void synchronize_rcu_bh_expedited(void)
extern void __rcu_init(void);
extern void rcu_check_callbacks(int cpu, int user);
extern void rcu_restart_cpu(int cpu);
extern long rcu_batches_completed(void);
extern long rcu_batches_completed_bh(void);
extern long rcu_batches_completed_sched(void);
static inline void rcu_init_sched(void)
{
}
#ifdef CONFIG_NO_HZ
void rcu_enter_nohz(void);
void rcu_exit_nohz(void);
......@@ -107,7 +106,7 @@ static inline void rcu_exit_nohz(void)
}
#endif /* CONFIG_NO_HZ */
/* A context switch is a grace period for rcutree. */
/* A context switch is a grace period for RCU-sched and RCU-bh. */
static inline int rcu_blocking_is_gp(void)
{
return num_online_cpus() == 1;
......
......@@ -778,7 +778,6 @@ static void __init do_initcalls(void)
*/
static void __init do_basic_setup(void)
{
rcu_init_sched(); /* needed by module_init stage. */
init_workqueues();
cpuset_init_smp();
usermodehelper_init();
......
......@@ -991,8 +991,6 @@ NORET_TYPE void do_exit(long code)
tsk->mempolicy = NULL;
#endif
#ifdef CONFIG_FUTEX
if (unlikely(!list_empty(&tsk->pi_state_list)))
exit_pi_state_list(tsk);
if (unlikely(current->pi_state_cache))
kfree(current->pi_state_cache);
#endif
......
......@@ -570,12 +570,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
/* Get rid of any futexes when releasing the mm */
#ifdef CONFIG_FUTEX
if (unlikely(tsk->robust_list))
if (unlikely(tsk->robust_list)) {
exit_robust_list(tsk);
tsk->robust_list = NULL;
}
#ifdef CONFIG_COMPAT
if (unlikely(tsk->compat_robust_list))
if (unlikely(tsk->compat_robust_list)) {
compat_exit_robust_list(tsk);
tsk->compat_robust_list = NULL;
}
#endif
if (unlikely(!list_empty(&tsk->pi_state_list)))
exit_pi_state_list(tsk);
#endif
/* Get rid of any cached register state */
......
......@@ -916,8 +916,8 @@ futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
hb1 = hash_futex(&key1);
hb2 = hash_futex(&key2);
double_lock_hb(hb1, hb2);
retry_private:
double_lock_hb(hb1, hb2);
op_ret = futex_atomic_op_inuser(op, uaddr2);
if (unlikely(op_ret < 0)) {
......@@ -2117,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* Unqueue the futex_q and determine which it was.
*/
plist_del(&q->list, &q->list.plist);
drop_futex_key_refs(&q->key);
if (timeout && !timeout->task)
ret = -ETIMEDOUT;
......
......@@ -90,6 +90,8 @@ NORET_TYPE void panic(const char * fmt, ...)
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
bust_spinlocks(0);
if (!panic_blink)
panic_blink = no_blink;
......@@ -136,7 +138,6 @@ NORET_TYPE void panic(const char * fmt, ...)
mdelay(1);
i++;
}
bust_spinlocks(0);
}
EXPORT_SYMBOL(panic);
......
......@@ -46,22 +46,15 @@
#include <linux/module.h>
#include <linux/kernel_stat.h>
enum rcu_barrier {
RCU_BARRIER_STD,
RCU_BARRIER_BH,
RCU_BARRIER_SCHED,
};
#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
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;
int rcu_scheduler_active __read_mostly;
static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
static struct rcu_head rcu_migrate_head[3];
static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);
/*
* Awaken the corresponding synchronize_rcu() instance now that a
* grace period has elapsed.
......@@ -164,129 +157,10 @@ void synchronize_rcu_bh(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
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);
atomic_inc(&rcu_barrier_cpu_count);
switch ((enum rcu_barrier)type) {
case RCU_BARRIER_STD:
call_rcu(head, rcu_barrier_callback);
break;
case RCU_BARRIER_BH:
call_rcu_bh(head, rcu_barrier_callback);
break;
case RCU_BARRIER_SCHED:
call_rcu_sched(head, rcu_barrier_callback);
break;
}
}
static inline void wait_migrated_callbacks(void)
{
wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
smp_mb(); /* In case we didn't sleep. */
}
/*
* Orchestrate the specified type of RCU barrier, waiting for all
* RCU callbacks of the specified type to complete.
*/
static void _rcu_barrier(enum rcu_barrier type)
{
BUG_ON(in_interrupt());
/* Take cpucontrol mutex to protect against CPU hotplug */
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);
on_each_cpu(rcu_barrier_func, (void *)type, 1);
if (atomic_dec_and_test(&rcu_barrier_cpu_count))
complete(&rcu_barrier_completion);
wait_for_completion(&rcu_barrier_completion);
mutex_unlock(&rcu_barrier_mutex);
wait_migrated_callbacks();
}
/**
* rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
*/
void rcu_barrier(void)
{
_rcu_barrier(RCU_BARRIER_STD);
}
EXPORT_SYMBOL_GPL(rcu_barrier);
/**
* rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
*/
void rcu_barrier_bh(void)
{
_rcu_barrier(RCU_BARRIER_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_BARRIER_SCHED);
}
EXPORT_SYMBOL_GPL(rcu_barrier_sched);
static void rcu_migrate_callback(struct rcu_head *notused)
{
if (atomic_dec_and_test(&rcu_migrate_type_count))
wake_up(&rcu_migrate_wq);
}
extern int rcu_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu);
static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
unsigned long action, void *hcpu)
{
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.
*
* These callbacks ensure _rcu_barrier() waits for all
* RCU callbacks of the specified type to complete.
*/
atomic_set(&rcu_migrate_type_count, 3);
call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
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)
......
This diff is collapsed.
......@@ -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");
......
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