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-rw-r--r--kernel/rcu/tree.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index dd08198..a6205a0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1133,8 +1133,10 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp)
* hold it, acquire the root rcu_node structure's lock in order to
* start one (if needed).
*/
- if (rnp != rnp_root)
+ if (rnp != rnp_root) {
raw_spin_lock(&rnp_root->lock);
+ smp_mb__after_unlock_lock();
+ }
/*
* Get a new grace-period number. If there really is no grace
@@ -1354,6 +1356,7 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
local_irq_restore(flags);
return;
}
+ smp_mb__after_unlock_lock();
__note_gp_changes(rsp, rnp, rdp);
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
@@ -1368,6 +1371,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
rcu_bind_gp_kthread();
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
if (rsp->gp_flags == 0) {
/* Spurious wakeup, tell caller to go back to sleep. */
raw_spin_unlock_irq(&rnp->lock);
@@ -1409,6 +1413,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
*/
rcu_for_each_node_breadth_first(rsp, rnp) {
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
rdp = this_cpu_ptr(rsp->rda);
rcu_preempt_check_blocked_tasks(rnp);
rnp->qsmask = rnp->qsmaskinit;
@@ -1463,6 +1468,7 @@ static int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
/* Clear flag to prevent immediate re-entry. */
if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
rsp->gp_flags &= ~RCU_GP_FLAG_FQS;
raw_spin_unlock_irq(&rnp->lock);
}
@@ -1480,6 +1486,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
struct rcu_node *rnp = rcu_get_root(rsp);
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
gp_duration = jiffies - rsp->gp_start;
if (gp_duration > rsp->gp_max)
rsp->gp_max = gp_duration;
@@ -1505,6 +1512,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
*/
rcu_for_each_node_breadth_first(rsp, rnp) {
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
ACCESS_ONCE(rnp->completed) = rsp->gpnum;
rdp = this_cpu_ptr(rsp->rda);
if (rnp == rdp->mynode)
@@ -1515,6 +1523,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
}
rnp = rcu_get_root(rsp);
raw_spin_lock_irq(&rnp->lock);
+ smp_mb__after_unlock_lock();
rcu_nocb_gp_set(rnp, nocb);
rsp->completed = rsp->gpnum; /* Declare grace period done. */
@@ -1749,6 +1758,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
rnp_c = rnp;
rnp = rnp->parent;
raw_spin_lock_irqsave(&rnp->lock, flags);
+ smp_mb__after_unlock_lock();
WARN_ON_ONCE(rnp_c->qsmask);
}
@@ -1778,6 +1788,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
rnp = rdp->mynode;
raw_spin_lock_irqsave(&rnp->lock, flags);
+ smp_mb__after_unlock_lock();
if (rdp->passed_quiesce == 0 || rdp->gpnum != rnp->gpnum ||
rnp->completed == rnp->gpnum) {
@@ -1992,6 +2003,7 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp)
mask = rdp->grpmask; /* rnp->grplo is constant. */
do {
raw_spin_lock(&rnp->lock); /* irqs already disabled. */
+ smp_mb__after_unlock_lock();
rnp->qsmaskinit &= ~mask;
if (rnp->qsmaskinit != 0) {
if (rnp != rdp->mynode)
@@ -2202,6 +2214,7 @@ static void force_qs_rnp(struct rcu_state *rsp,
cond_resched();
mask = 0;
raw_spin_lock_irqsave(&rnp->lock, flags);
+ smp_mb__after_unlock_lock();
if (!rcu_gp_in_progress(rsp)) {
raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
@@ -2231,6 +2244,7 @@ static void force_qs_rnp(struct rcu_state *rsp,
rnp = rcu_get_root(rsp);
if (rnp->qsmask == 0) {
raw_spin_lock_irqsave(&rnp->lock, flags);
+ smp_mb__after_unlock_lock();
rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */
}
}
@@ -2263,6 +2277,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
/* Reached the root of the rcu_node tree, acquire lock. */
raw_spin_lock_irqsave(&rnp_old->lock, flags);
+ smp_mb__after_unlock_lock();
raw_spin_unlock(&rnp_old->fqslock);
if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
rsp->n_force_qs_lh++;
@@ -2378,6 +2393,7 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
struct rcu_node *rnp_root = rcu_get_root(rsp);
raw_spin_lock(&rnp_root->lock);
+ smp_mb__after_unlock_lock();
rcu_start_gp(rsp);
raw_spin_unlock(&rnp_root->lock);
} else {
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