diff options
| -rw-r--r-- | kernel/locking/qspinlock.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 7868418..365b203 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -407,6 +407,16 @@ queue: pv_wait_node(node); arch_mcs_spin_lock_contended(&node->locked); + + /* + * While waiting for the MCS lock, the next pointer may have + * been set by another lock waiter. We optimistically load + * the next pointer & prefetch the cacheline for writing + * to reduce latency in the upcoming MCS unlock operation. + */ + next = READ_ONCE(node->next); + if (next) + prefetchw(next); } /* |
