diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 9 | ||||
| -rw-r--r-- | kernel/lockdep.c | 1 | ||||
| -rw-r--r-- | kernel/pid.c | 4 | ||||
| -rw-r--r-- | kernel/rcutree.h | 21 | ||||
| -rw-r--r-- | kernel/rcutree_plugin.h | 8 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 2 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 22 | ||||
| -rw-r--r-- | kernel/trace/trace_event_profile.c | 4 |
9 files changed, 49 insertions, 24 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index ce1e48c2d93..cce59cb5ee6 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -87,7 +87,7 @@ static void __exit_signal(struct task_struct *tsk) sighand = rcu_dereference_check(tsk->sighand, rcu_read_lock_held() || - lockdep_is_held(&tasklist_lock)); + lockdep_tasklist_lock_is_held()); spin_lock(&sighand->siglock); posix_cpu_timers_exit(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index 1beb6c303c4..4799c5f0e6d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -86,7 +86,14 @@ int max_threads; /* tunable limit on nr_threads */ DEFINE_PER_CPU(unsigned long, process_counts) = 0; __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */ -EXPORT_SYMBOL_GPL(tasklist_lock); + +#ifdef CONFIG_PROVE_RCU +int lockdep_tasklist_lock_is_held(void) +{ + return lockdep_is_held(&tasklist_lock); +} +EXPORT_SYMBOL_GPL(lockdep_tasklist_lock_is_held); +#endif /* #ifdef CONFIG_PROVE_RCU */ int nr_processes(void) { diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 0c30d0455de..681bc2e1e18 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3822,6 +3822,7 @@ void lockdep_rcu_dereference(const char *file, const int line) printk("%s:%d invoked rcu_dereference_check() without protection!\n", file, line); printk("\nother info that might help us debug this:\n\n"); + printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks); lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); dump_stack(); diff --git a/kernel/pid.c b/kernel/pid.c index 86b296943e5..aebb30d9c23 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -367,7 +367,9 @@ struct task_struct *pid_task(struct pid *pid, enum pid_type type) struct task_struct *result = NULL; if (pid) { struct hlist_node *first; - first = rcu_dereference_check(pid->tasks[type].first, rcu_read_lock_held() || lockdep_is_held(&tasklist_lock)); + first = rcu_dereference_check(pid->tasks[type].first, + rcu_read_lock_held() || + lockdep_tasklist_lock_is_held()); if (first) result = hlist_entry(first, struct task_struct, pids[(type)].node); } diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 1439eb504c2..4a525a30e08 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -246,12 +246,21 @@ struct rcu_data { #define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */ #ifdef CONFIG_RCU_CPU_STALL_DETECTOR -#define RCU_SECONDS_TILL_STALL_CHECK (10 * HZ) /* for rsp->jiffies_stall */ -#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ) /* for rsp->jiffies_stall */ -#define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */ - /* to take at least one */ - /* scheduling clock irq */ - /* before ratting on them. */ + +#ifdef CONFIG_PROVE_RCU +#define RCU_STALL_DELAY_DELTA (5 * HZ) +#else +#define RCU_STALL_DELAY_DELTA 0 +#endif + +#define RCU_SECONDS_TILL_STALL_CHECK (10 * HZ + RCU_STALL_DELAY_DELTA) + /* for rsp->jiffies_stall */ +#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ + RCU_STALL_DELAY_DELTA) + /* for rsp->jiffies_stall */ +#define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */ + /* to take at least one */ + /* scheduling clock irq */ + /* before ratting on them. */ #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 464ad2cdee0..79b53bda894 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1010,6 +1010,10 @@ int rcu_needs_cpu(int cpu) int c = 0; int thatcpu; + /* Check for being in the holdoff period. */ + if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies) + return rcu_needs_cpu_quick_check(cpu); + /* Don't bother unless we are the last non-dyntick-idle CPU. */ for_each_cpu_not(thatcpu, nohz_cpu_mask) if (thatcpu != cpu) { @@ -1041,10 +1045,8 @@ int rcu_needs_cpu(int cpu) } /* If RCU callbacks are still pending, RCU still needs this CPU. */ - if (c) { + if (c) raise_softirq(RCU_SOFTIRQ); - per_cpu(rcu_dyntick_holdoff, cpu) = jiffies; - } return c; } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 3e1fd96c6cf..5a5ea2cd924 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -3476,7 +3476,7 @@ static void run_rebalance_domains(struct softirq_action *h) static inline int on_null_domain(int cpu) { - return !rcu_dereference(cpu_rq(cpu)->sd); + return !rcu_dereference_sched(cpu_rq(cpu)->sd); } /* diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index bb53edbb5c8..d9062f5cc0c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -27,6 +27,7 @@ #include <linux/ctype.h> #include <linux/list.h> #include <linux/hash.h> +#include <linux/rcupdate.h> #include <trace/events/sched.h> @@ -84,18 +85,22 @@ ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; +/* + * Traverse the ftrace_list, invoking all entries. The reason that we + * can use rcu_dereference_raw() is that elements removed from this list + * are simply leaked, so there is no need to interact with a grace-period + * mechanism. The rcu_dereference_raw() calls are needed to handle + * concurrent insertions into the ftrace_list. + * + * Silly Alpha and silly pointer-speculation compiler optimizations! + */ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) { - struct ftrace_ops *op = ftrace_list; - - /* in case someone actually ports this to alpha! */ - read_barrier_depends(); + struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ while (op != &ftrace_list_end) { - /* silly alpha */ - read_barrier_depends(); op->func(ip, parent_ip); - op = op->next; + op = rcu_dereference_raw(op->next); /*see above*/ }; } @@ -150,8 +155,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) * the ops->next pointer is valid before another CPU sees * the ops pointer included into the ftrace_list. */ - smp_wmb(); - ftrace_list = ops; + rcu_assign_pointer(ftrace_list, ops); if (ftrace_enabled) { ftrace_func_t func; diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index f0d69300507..c1cc3ab633d 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -138,9 +138,9 @@ __kprobes void *ftrace_perf_buf_prepare(int size, unsigned short type, cpu = smp_processor_id(); if (in_nmi()) - trace_buf = rcu_dereference(perf_trace_buf_nmi); + trace_buf = rcu_dereference_sched(perf_trace_buf_nmi); else - trace_buf = rcu_dereference(perf_trace_buf); + trace_buf = rcu_dereference_sched(perf_trace_buf); if (!trace_buf) goto err; |