#include <linux/cache.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
-#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+#define RCU_SECONDS_TILL_STALL_CHECK (10 * 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 */
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;
spinlock_t lock ____cacheline_internodealigned_in_smp;
- cpumask_t cpumask; /* CPUs that need to switch in order */
- /* for current batch to proceed. */
+ DECLARE_BITMAP(cpumask, NR_CPUS); /* CPUs that need to switch for */
+ /* current batch to proceed. */
} ____cacheline_internodealigned_in_smp;
/* Is batch a before batch 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 */
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 */
struct rcu_head barrier;
};
-DECLARE_PER_CPU(struct rcu_data, rcu_data);
-DECLARE_PER_CPU(struct rcu_data, rcu_bh_data);
-
/*
* Increment the quiescent state counter.
* The counter is a bit degenerated: We do not need to know
* how many quiescent states passed, just if there was at least
* one since the start of the grace period. Thus just a flag.
*/
-static inline void rcu_qsctr_inc(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
- rdp->passed_quiesc = 1;
-}
-static inline void rcu_bh_qsctr_inc(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
- rdp->passed_quiesc = 1;
-}
+extern void rcu_qsctr_inc(int cpu);
+extern void rcu_bh_qsctr_inc(int cpu);
extern int rcu_pending(int cpu);
extern int rcu_needs_cpu(int cpu);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern struct lockdep_map rcu_lock_map;
# define rcu_read_acquire() \
- lock_acquire(&rcu_lock_map, 0, 0, 2, 1, _THIS_IP_)
+ lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_)
# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_)
#else
# define rcu_read_acquire() do { } while (0)
#define rcu_enter_nohz() do { } while (0)
#define rcu_exit_nohz() do { } while (0)
+/* A context switch is a grace period for rcuclassic. */
+static inline int rcu_blocking_is_gp(void)
+{
+ return num_online_cpus() == 1;
+}
+
#endif /* __LINUX_RCUCLASSIC_H */