diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/compiler.h | 4 | ||||
| -rw-r--r-- | include/linux/rcuclassic.h | 37 | ||||
| -rw-r--r-- | include/linux/rculist.h | 14 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 20 | ||||
| -rw-r--r-- | include/linux/rcupreempt.h | 11 |
5 files changed, 58 insertions, 28 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index c8bd2daf95ec..8322141ee480 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -190,7 +190,9 @@ extern void __chk_io_ptr(const volatile void __iomem *); * ACCESS_ONCE() in different C statements. * * This macro does absolutely -nothing- to prevent the CPU from reordering, - * merging, or refetching absolutely anything at any time. + * merging, or refetching absolutely anything at any time. Its main intended + * use is to mediate communication between process-level code and irq/NMI + * handlers, all running on the same CPU. */ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h index 4ab843622727..5f89b62e6983 100644 --- a/include/linux/rcuclassic.h +++ b/include/linux/rcuclassic.h @@ -40,12 +40,21 @@ #include <linux/cpumask.h> #include <linux/seqlock.h> +#ifdef CONFIG_RCU_CPU_STALL_DETECTOR +#define RCU_SECONDS_TILL_STALL_CHECK ( 3 * HZ) /* for rcp->jiffies_stall */ +#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ) /* for rcp->jiffies_stall */ +#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ /* Global control variables for rcupdate callback mechanism. */ struct rcu_ctrlblk { long cur; /* Current batch number. */ long completed; /* Number of the last completed batch */ - int next_pending; /* Is the next batch already waiting? */ + long pending; /* Number of the last pending batch */ +#ifdef CONFIG_RCU_CPU_STALL_DETECTOR + unsigned long gp_start; /* Time at which GP started in jiffies. */ + unsigned long jiffies_stall; + /* Time at which to check for CPU stalls. */ +#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ int signaled; @@ -66,11 +75,7 @@ static inline int rcu_batch_after(long a, long b) return (a - b) > 0; } -/* - * Per-CPU data for Read-Copy UPdate. - * nxtlist - new callbacks are added here - * curlist - current batch for which quiescent cycle started if any - */ +/* Per-CPU data for Read-Copy UPdate. */ struct rcu_data { /* 1) quiescent state handling : */ long quiescbatch; /* Batch # for grace period */ @@ -78,12 +83,24 @@ struct rcu_data { int qs_pending; /* core waits for quiesc state */ /* 2) batch handling */ - long batch; /* Batch # for current RCU batch */ + /* + * if nxtlist is not NULL, then: + * batch: + * The batch # for the last entry of nxtlist + * [*nxttail[1], NULL = *nxttail[2]): + * Entries that batch # <= batch + * [*nxttail[0], *nxttail[1]): + * Entries that batch # <= batch - 1 + * [nxtlist, *nxttail[0]): + * Entries that batch # <= batch - 2 + * The grace period for these entries has completed, and + * the other grace-period-completed entries may be moved + * here temporarily in rcu_process_callbacks(). + */ + long batch; struct rcu_head *nxtlist; - struct rcu_head **nxttail; + struct rcu_head **nxttail[3]; long qlen; /* # of queued callbacks */ - struct rcu_head *curlist; - struct rcu_head **curtail; struct rcu_head *donelist; struct rcu_head **donetail; long blimit; /* Upper limit on a processed batch */ diff --git a/include/linux/rculist.h b/include/linux/rculist.h index eb4443c7e05b..e649bd3f2c97 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -198,20 +198,6 @@ static inline void list_splice_init_rcu(struct list_head *list, at->prev = last; } -/** - * list_for_each_rcu - iterate over an rcu-protected list - * @pos: the &struct list_head to use as a loop cursor. - * @head: the head for your list. - * - * This list-traversal primitive may safely run concurrently with - * the _rcu list-mutation primitives such as list_add_rcu() - * as long as the traversal is guarded by rcu_read_lock(). - */ -#define list_for_each_rcu(pos, head) \ - for (pos = rcu_dereference((head)->next); \ - prefetch(pos->next), pos != (head); \ - pos = rcu_dereference(pos->next)) - #define __list_for_each_rcu(pos, head) \ for (pos = rcu_dereference((head)->next); \ pos != (head); \ diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index e8b4039cfb2f..86f1f5e43e33 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -133,6 +133,26 @@ struct rcu_head { #define rcu_read_unlock_bh() __rcu_read_unlock_bh() /** + * rcu_read_lock_sched - mark the beginning of a RCU-classic critical section + * + * Should be used with either + * - synchronize_sched() + * or + * - call_rcu_sched() and rcu_barrier_sched() + * on the write-side to insure proper synchronization. + */ +#define rcu_read_lock_sched() preempt_disable() + +/* + * rcu_read_unlock_sched - marks the end of a RCU-classic critical section + * + * See rcu_read_lock_sched for more information. + */ +#define rcu_read_unlock_sched() preempt_enable() + + + +/** * rcu_dereference - fetch an RCU-protected pointer in an * RCU read-side critical section. This pointer may later * be safely dereferenced. diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h index 0967f03b0705..3e05c09b54a2 100644 --- a/include/linux/rcupreempt.h +++ b/include/linux/rcupreempt.h @@ -57,7 +57,13 @@ static inline void rcu_qsctr_inc(int cpu) rdssp->sched_qs++; } #define rcu_bh_qsctr_inc(cpu) -#define call_rcu_bh(head, rcu) call_rcu(head, rcu) + +/* + * Someone might want to pass call_rcu_bh as a function pointer. + * So this needs to just be a rename and not a macro function. + * (no parentheses) + */ +#define call_rcu_bh call_rcu /** * call_rcu_sched - Queue RCU callback for invocation after sched grace period. @@ -111,7 +117,6 @@ extern struct rcupreempt_trace *rcupreempt_trace_cpu(int cpu); struct softirq_action; #ifdef CONFIG_NO_HZ -DECLARE_PER_CPU(struct rcu_dyntick_sched, rcu_dyntick_sched); static inline void rcu_enter_nohz(void) { @@ -126,8 +131,8 @@ static inline void rcu_exit_nohz(void) { static DEFINE_RATELIMIT_STATE(rs, 10 * HZ, 1); - smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ __get_cpu_var(rcu_dyntick_sched).dynticks++; + smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ WARN_ON_RATELIMIT(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1), &rs); } |