diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 19 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 8 |
2 files changed, 15 insertions, 12 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 1a617b9dffb0..c2b04daf1190 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -150,7 +150,7 @@ static void __maybe_unused sync_exp_reset_tree(void) static bool sync_rcu_exp_done(struct rcu_node *rnp) { raw_lockdep_assert_held_rcu_node(rnp); - return rnp->exp_tasks == NULL && + return READ_ONCE(rnp->exp_tasks) == NULL && READ_ONCE(rnp->expmask) == 0; } @@ -373,7 +373,7 @@ static void sync_rcu_exp_select_node_cpus(struct work_struct *wp) * until such time as the ->expmask bits are cleared. */ if (rcu_preempt_has_tasks(rnp)) - rnp->exp_tasks = rnp->blkd_tasks.next; + WRITE_ONCE(rnp->exp_tasks, rnp->blkd_tasks.next); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); /* IPI the remaining CPUs for expedited quiescent state. */ @@ -542,8 +542,8 @@ static void synchronize_rcu_expedited_wait(void) } pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n", jiffies - jiffies_start, rcu_state.expedited_sequence, - READ_ONCE(rnp_root->expmask), - ".T"[!!rnp_root->exp_tasks]); + data_race(rnp_root->expmask), + ".T"[!!data_race(rnp_root->exp_tasks)]); if (ndetected) { pr_err("blocking rcu_node structures:"); rcu_for_each_node_breadth_first(rnp) { @@ -553,8 +553,8 @@ static void synchronize_rcu_expedited_wait(void) continue; pr_cont(" l=%u:%d-%d:%#lx/%c", rnp->level, rnp->grplo, rnp->grphi, - READ_ONCE(rnp->expmask), - ".T"[!!rnp->exp_tasks]); + data_race(rnp->expmask), + ".T"[!!data_race(rnp->exp_tasks)]); } pr_cont("\n"); } @@ -721,17 +721,20 @@ static void sync_sched_exp_online_cleanup(int cpu) */ static int rcu_print_task_exp_stall(struct rcu_node *rnp) { - struct task_struct *t; + unsigned long flags; int ndetected = 0; + struct task_struct *t; - if (!rnp->exp_tasks) + if (!READ_ONCE(rnp->exp_tasks)) return 0; + raw_spin_lock_irqsave_rcu_node(rnp, flags); t = list_entry(rnp->exp_tasks->prev, struct task_struct, rcu_node_entry); list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) { pr_cont(" P%d", t->pid); ndetected++; } + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return ndetected; } diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 097635c41135..35d77db035bd 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -226,7 +226,7 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp) WARN_ON_ONCE(rnp->completedqs == rnp->gp_seq); } if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD)) - rnp->exp_tasks = &t->rcu_node_entry; + WRITE_ONCE(rnp->exp_tasks, &t->rcu_node_entry); WARN_ON_ONCE(!(blkd_state & RCU_GP_BLKD) != !(rnp->qsmask & rdp->grpmask)); WARN_ON_ONCE(!(blkd_state & RCU_EXP_BLKD) != @@ -500,7 +500,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) if (&t->rcu_node_entry == rnp->gp_tasks) WRITE_ONCE(rnp->gp_tasks, np); if (&t->rcu_node_entry == rnp->exp_tasks) - rnp->exp_tasks = np; + WRITE_ONCE(rnp->exp_tasks, np); if (IS_ENABLED(CONFIG_RCU_BOOST)) { /* Snapshot ->boost_mtx ownership w/rnp->lock held. */ drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t; @@ -761,7 +761,7 @@ dump_blkd_tasks(struct rcu_node *rnp, int ncheck) __func__, rnp1->grplo, rnp1->grphi, rnp1->qsmask, rnp1->qsmaskinit, rnp1->qsmaskinitnext); pr_info("%s: ->gp_tasks %p ->boost_tasks %p ->exp_tasks %p\n", __func__, READ_ONCE(rnp->gp_tasks), rnp->boost_tasks, - rnp->exp_tasks); + READ_ONCE(rnp->exp_tasks)); pr_info("%s: ->blkd_tasks", __func__); i = 0; list_for_each(lhp, &rnp->blkd_tasks) { @@ -1036,7 +1036,7 @@ static int rcu_boost_kthread(void *arg) for (;;) { WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_WAITING); trace_rcu_utilization(TPS("End boost kthread@rcu_wait")); - rcu_wait(rnp->boost_tasks || rnp->exp_tasks); + rcu_wait(rnp->boost_tasks || READ_ONCE(rnp->exp_tasks)); trace_rcu_utilization(TPS("Start boost kthread@rcu_wait")); WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_RUNNING); more2boost = rcu_boost(rnp); |