diff options
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 55 |
1 files changed, 45 insertions, 10 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index b023e540711..752ffaa0d68 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2104,7 +2104,8 @@ bool rcu_is_nocb_cpu(int cpu) static void __call_rcu_nocb_enqueue(struct rcu_data *rdp, struct rcu_head *rhp, struct rcu_head **rhtp, - int rhcount, int rhcount_lazy) + int rhcount, int rhcount_lazy, + unsigned long flags) { int len; struct rcu_head **old_rhpp; @@ -2125,9 +2126,16 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp, } len = atomic_long_read(&rdp->nocb_q_count); if (old_rhpp == &rdp->nocb_head) { - wake_up(&rdp->nocb_wq); /* ... only if queue was empty ... */ + if (!irqs_disabled_flags(flags)) { + wake_up(&rdp->nocb_wq); /* ... if queue was empty ... */ + trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, + TPS("WakeEmpty")); + } else { + rdp->nocb_defer_wakeup = true; + trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, + TPS("WakeEmptyIsDeferred")); + } rdp->qlen_last_fqs_check = 0; - trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("WakeEmpty")); } else if (len > rdp->qlen_last_fqs_check + qhimark) { wake_up_process(t); /* ... or if many callbacks queued. */ rdp->qlen_last_fqs_check = LONG_MAX / 2; @@ -2148,12 +2156,12 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp, * "rcuo" kthread can find it. */ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, - bool lazy) + bool lazy, unsigned long flags) { if (!rcu_is_nocb_cpu(rdp->cpu)) return 0; - __call_rcu_nocb_enqueue(rdp, rhp, &rhp->next, 1, lazy); + __call_rcu_nocb_enqueue(rdp, rhp, &rhp->next, 1, lazy, flags); if (__is_kfree_rcu_offset((unsigned long)rhp->func)) trace_rcu_kfree_callback(rdp->rsp->name, rhp, (unsigned long)rhp->func, @@ -2171,7 +2179,8 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, * not a no-CBs CPU. */ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, - struct rcu_data *rdp) + struct rcu_data *rdp, + unsigned long flags) { long ql = rsp->qlen; long qll = rsp->qlen_lazy; @@ -2185,14 +2194,14 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, /* First, enqueue the donelist, if any. This preserves CB ordering. */ if (rsp->orphan_donelist != NULL) { __call_rcu_nocb_enqueue(rdp, rsp->orphan_donelist, - rsp->orphan_donetail, ql, qll); + rsp->orphan_donetail, ql, qll, flags); ql = qll = 0; rsp->orphan_donelist = NULL; rsp->orphan_donetail = &rsp->orphan_donelist; } if (rsp->orphan_nxtlist != NULL) { __call_rcu_nocb_enqueue(rdp, rsp->orphan_nxtlist, - rsp->orphan_nxttail, ql, qll); + rsp->orphan_nxttail, ql, qll, flags); ql = qll = 0; rsp->orphan_nxtlist = NULL; rsp->orphan_nxttail = &rsp->orphan_nxtlist; @@ -2314,6 +2323,22 @@ static int rcu_nocb_kthread(void *arg) return 0; } +/* Is a deferred wakeup of rcu_nocb_kthread() required? */ +static bool rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp) +{ + return ACCESS_ONCE(rdp->nocb_defer_wakeup); +} + +/* Do a deferred wakeup of rcu_nocb_kthread(). */ +static void do_nocb_deferred_wakeup(struct rcu_data *rdp) +{ + if (!rcu_nocb_need_deferred_wakeup(rdp)) + return; + ACCESS_ONCE(rdp->nocb_defer_wakeup) = false; + wake_up(&rdp->nocb_wq); + trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("DeferredWakeEmpty")); +} + /* Initialize per-rcu_data variables for no-CBs CPUs. */ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) { @@ -2369,13 +2394,14 @@ static void rcu_init_one_nocb(struct rcu_node *rnp) } static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, - bool lazy) + bool lazy, unsigned long flags) { return 0; } static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, - struct rcu_data *rdp) + struct rcu_data *rdp, + unsigned long flags) { return 0; } @@ -2384,6 +2410,15 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) { } +static bool rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp) +{ + return false; +} + +static void do_nocb_deferred_wakeup(struct rcu_data *rdp) +{ +} + static void __init rcu_spawn_nocb_kthreads(struct rcu_state *rsp) { } |