Messages in this thread Patch in this message | | | From | Nicholas Piggin <> | Subject | [PATCH 12/13] locking/qspinlock: separate pv_wait_node from the non-paravirt path | Date | Tue, 5 Jul 2022 00:38:19 +1000 |
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pv_wait_node waits until node->locked is non-zero, no need for the pv case to wait again by also executing the !pv code path.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- kernel/locking/qspinlock.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 9db168753124..19e2f286be0a 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -862,10 +862,11 @@ static inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, bool parav /* Link @node into the waitqueue. */ WRITE_ONCE(prev->next, node); + /* Wait for mcs node lock to be released */ if (paravirt) pv_wait_node(node, prev); - /* Wait for mcs node lock to be released */ - smp_cond_load_acquire(&node->locked, VAL); + else + smp_cond_load_acquire(&node->locked, VAL); /* * While waiting for the MCS lock, the next pointer may have -- 2.35.1
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