From: Feifei Wang <feifei.wang2@arm.com>
Date: Mon, 1 Nov 2021 06:00:05 +0000 (+0800)
Subject: mcslock: use wait until scheme for unlock
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=4ed4e554ac015de0a2661310ea6bb48ea6e1c977;p=dpdk.git

mcslock: use wait until scheme for unlock

Instead of polling for mcslock to be updated, use wait until scheme
for this case.

Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
---

diff --git a/lib/eal/include/generic/rte_mcslock.h b/lib/eal/include/generic/rte_mcslock.h
index 34f33c64a5..f15b785358 100644
--- a/lib/eal/include/generic/rte_mcslock.h
+++ b/lib/eal/include/generic/rte_mcslock.h
@@ -116,8 +116,10 @@ rte_mcslock_unlock(rte_mcslock_t **msl, rte_mcslock_t *me)
 		/* More nodes added to the queue by other CPUs.
 		 * Wait until the next pointer is set.
 		 */
-		while (__atomic_load_n(&me->next, __ATOMIC_RELAXED) == NULL)
-			rte_pause();
+		uintptr_t *next;
+		next = (uintptr_t *)&me->next;
+		RTE_WAIT_UNTIL_MASKED(next, UINTPTR_MAX, !=, 0,
+			__ATOMIC_RELAXED);
 	}
 
 	/* Pass lock to next waiter. */