diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/srcu.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c index 665bc9951523..e773129c8b08 100644 --- a/kernel/rcu/srcu.c +++ b/kernel/rcu/srcu.c @@ -320,7 +320,16 @@ static bool try_check_zero(struct srcu_struct *sp, int idx, int trycount) */ static void srcu_flip(struct srcu_struct *sp) { - sp->completed++; + WRITE_ONCE(sp->completed, sp->completed + 1); + + /* + * Ensure that if the updater misses an __srcu_read_unlock() + * increment, that task's next __srcu_read_lock() will see the + * above counter update. Note that both this memory barrier + * and the one in srcu_readers_active_idx_check() provide the + * guarantee for __srcu_read_lock(). + */ + smp_mb(); /* D */ /* Pairs with C. */ } /* |