diff options
Diffstat (limited to 'kernel/rcu/tree.c')
-rw-r--r-- | kernel/rcu/tree.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 11ae2747701b..5797cf2909b0 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1358,10 +1358,11 @@ static void __maybe_unused rcu_advance_cbs_nowake(struct rcu_node *rnp, struct rcu_data *rdp) { rcu_lockdep_assert_cblist_protected(rdp); - if (!rcu_seq_state(rcu_seq_current(&rnp->gp_seq)) || - !raw_spin_trylock_rcu_node(rnp)) + if (!rcu_seq_state(rcu_seq_current(&rnp->gp_seq)) || !raw_spin_trylock_rcu_node(rnp)) return; - WARN_ON_ONCE(rcu_advance_cbs(rnp, rdp)); + // The grace period cannot end while we hold the rcu_node lock. + if (rcu_seq_state(rcu_seq_current(&rnp->gp_seq))) + WARN_ON_ONCE(rcu_advance_cbs(rnp, rdp)); raw_spin_unlock_rcu_node(rnp); } @@ -1602,7 +1603,7 @@ static void rcu_gp_fqs(bool first_time) struct rcu_node *rnp = rcu_get_root(); WRITE_ONCE(rcu_state.gp_activity, jiffies); - rcu_state.n_force_qs++; + WRITE_ONCE(rcu_state.n_force_qs, rcu_state.n_force_qs + 1); if (first_time) { /* Collect dyntick-idle snapshots. */ force_qs_rnp(dyntick_save_progress_counter); @@ -2207,7 +2208,7 @@ static void rcu_do_batch(struct rcu_data *rdp) /* Reset ->qlen_last_fqs_check trigger if enough CBs have drained. */ if (count == 0 && rdp->qlen_last_fqs_check != 0) { rdp->qlen_last_fqs_check = 0; - rdp->n_force_qs_snap = rcu_state.n_force_qs; + rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs); } else if (count < rdp->qlen_last_fqs_check - qhimark) rdp->qlen_last_fqs_check = count; @@ -2535,10 +2536,10 @@ static void __call_rcu_core(struct rcu_data *rdp, struct rcu_head *head, } else { /* Give the grace period a kick. */ rdp->blimit = DEFAULT_MAX_RCU_BLIMIT; - if (rcu_state.n_force_qs == rdp->n_force_qs_snap && + if (READ_ONCE(rcu_state.n_force_qs) == rdp->n_force_qs_snap && rcu_segcblist_first_pend_cb(&rdp->cblist) != head) rcu_force_quiescent_state(); - rdp->n_force_qs_snap = rcu_state.n_force_qs; + rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs); rdp->qlen_last_fqs_check = rcu_segcblist_n_cbs(&rdp->cblist); } } @@ -3029,7 +3030,7 @@ int rcutree_prepare_cpu(unsigned int cpu) /* Set up local state, ensuring consistent view of global state. */ raw_spin_lock_irqsave_rcu_node(rnp, flags); rdp->qlen_last_fqs_check = 0; - rdp->n_force_qs_snap = rcu_state.n_force_qs; + rdp->n_force_qs_snap = READ_ONCE(rcu_state.n_force_qs); rdp->blimit = blimit; if (rcu_segcblist_empty(&rdp->cblist) && /* No early-boot CBs? */ !rcu_segcblist_is_offloaded(&rdp->cblist)) |