1 files changed, 10 insertions, 32 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a54587dc13f0..fd2f582a6db0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3183,16 +3183,10 @@ unsigned long get_state_synchronize_rcu(void)
 {
         /*
          * Any prior manipulation of RCU-protected data must happen
-         * before the load from ->gpnum.
+         * before the load from ->gp_seq.
          */
         smp_mb();  /* ^^^ */
-
-        /*
-         * Make sure this load happens before the purportedly
-         * time-consuming work between get_state_synchronize_rcu()
-         * and cond_synchronize_rcu().
-         */
-        return smp_load_acquire(&rcu_state_p->gpnum);
+        return rcu_seq_snap(&rcu_state_p->gp_seq);
 }
 EXPORT_SYMBOL_GPL(get_state_synchronize_rcu);
 
@@ -3212,15 +3206,10 @@ EXPORT_SYMBOL_GPL(get_state_synchronize_rcu);
  */
 void cond_synchronize_rcu(unsigned long oldstate)
 {
-        unsigned long newstate;
-
-        /*
-         * Ensure that this load happens before any RCU-destructive
-         * actions the caller might carry out after we return.
-         */
-        newstate = smp_load_acquire(&rcu_state_p->completed);
-        if (ULONG_CMP_GE(oldstate, newstate))
+        if (!rcu_seq_done(&rcu_state_p->gp_seq, oldstate))
                 synchronize_rcu();
+        else
+                smp_mb(); /* Ensure GP ends before subsequent accesses. */
 }
 EXPORT_SYMBOL_GPL(cond_synchronize_rcu);
 
@@ -3235,16 +3224,10 @@ unsigned long get_state_synchronize_sched(void)
 {
         /*
          * Any prior manipulation of RCU-protected data must happen
-         * before the load from ->gpnum.
+         * before the load from ->gp_seq.
          */
         smp_mb();  /* ^^^ */
-
-        /*
-         * Make sure this load happens before the purportedly
-         * time-consuming work between get_state_synchronize_sched()
-         * and cond_synchronize_sched().
-         */
-        return smp_load_acquire(&rcu_sched_state.gpnum);
+        return rcu_seq_snap(&rcu_sched_state.gp_seq);
 }
 EXPORT_SYMBOL_GPL(get_state_synchronize_sched);
 
@@ -3264,15 +3247,10 @@ EXPORT_SYMBOL_GPL(get_state_synchronize_sched);
  */
 void cond_synchronize_sched(unsigned long oldstate)
 {
-        unsigned long newstate;
-
-        /*
-         * Ensure that this load happens before any RCU-destructive
-         * actions the caller might carry out after we return.
-         */
-        newstate = smp_load_acquire(&rcu_sched_state.completed);
-        if (ULONG_CMP_GE(oldstate, newstate))
+        if (!rcu_seq_done(&rcu_sched_state.gp_seq, oldstate))
                 synchronize_sched();
+        else
+                smp_mb(); /* Ensure GP ends before subsequent accesses. */
 }
 EXPORT_SYMBOL_GPL(cond_synchronize_sched);