diff options
| -rw-r--r-- | kernel/rcu/tree.c | 17 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 3 |
2 files changed, 16 insertions, 4 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e8fff14e417b..1df100cb7a62 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -103,6 +103,7 @@ struct rcu_state sname##_state = { \ .name = RCU_STATE_NAME(sname), \ .abbr = sabbr, \ .exp_mutex = __MUTEX_INITIALIZER(sname##_state.exp_mutex), \ + .exp_wake_mutex = __MUTEX_INITIALIZER(sname##_state.exp_wake_mutex), \ } RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched); @@ -3637,7 +3638,7 @@ static bool exp_funnel_lock(struct rcu_state *rsp, unsigned long s) trace_rcu_exp_funnel_lock(rsp->name, rnp->level, rnp->grplo, rnp->grphi, TPS("wait")); - wait_event(rnp->exp_wq[(s >> 1) & 0x1], + wait_event(rnp->exp_wq[(s >> 1) & 0x3], sync_exp_work_done(rsp, &rdp->exp_workdone2, s)); return true; @@ -3857,6 +3858,14 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) synchronize_sched_expedited_wait(rsp); rcu_exp_gp_seq_end(rsp); trace_rcu_exp_grace_period(rsp->name, s, TPS("end")); + + /* + * Switch over to wakeup mode, allowing the next GP, but -only- the + * next GP, to proceed. + */ + mutex_lock(&rsp->exp_wake_mutex); + mutex_unlock(&rsp->exp_mutex); + rcu_for_each_node_breadth_first(rsp, rnp) { if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) { spin_lock(&rnp->exp_lock); @@ -3865,10 +3874,10 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) rnp->exp_seq_rq = s; spin_unlock(&rnp->exp_lock); } - wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x1]); + wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x3]); } trace_rcu_exp_grace_period(rsp->name, s, TPS("endwake")); - mutex_unlock(&rsp->exp_mutex); + mutex_unlock(&rsp->exp_wake_mutex); } /** @@ -4530,6 +4539,8 @@ static void __init rcu_init_one(struct rcu_state *rsp) rcu_init_one_nocb(rnp); init_waitqueue_head(&rnp->exp_wq[0]); init_waitqueue_head(&rnp->exp_wq[1]); + init_waitqueue_head(&rnp->exp_wq[2]); + init_waitqueue_head(&rnp->exp_wq[3]); spin_lock_init(&rnp->exp_lock); } } diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index f9d4fbb1e014..1194ab0da56a 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -250,7 +250,7 @@ struct rcu_node { spinlock_t exp_lock ____cacheline_internodealigned_in_smp; unsigned long exp_seq_rq; - wait_queue_head_t exp_wq[2]; + wait_queue_head_t exp_wq[4]; } ____cacheline_internodealigned_in_smp; /* @@ -502,6 +502,7 @@ struct rcu_state { /* End of fields guarded by barrier_mutex. */ struct mutex exp_mutex; /* Serialize expedited GP. */ + struct mutex exp_wake_mutex; /* Serialize wakeup. */ unsigned long expedited_sequence; /* Take a ticket. */ atomic_long_t expedited_normal; /* # fallbacks to normal. */ atomic_t expedited_need_qs; /* # CPUs left to check in. */ |