Merge 72078891843ce0d5b8e95040d09ba92913916af9 on remote branch

Change-Id: I219a5f0e8bd6ee3be3ba0d49230dde908d35dc25

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index c30d07e99dba..72de6444934d 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -44,7 +44,12 @@ retry:
 		was_locked = 1;
 	} else {
 		local_irq_restore(flags);
-		cpu_relax();
+		/*
+		 * Wait for the lock to release before jumping to
+		 * atomic_cmpxchg() in order to mitigate the thundering herd
+		 * problem.
+		 */
+		do { cpu_relax(); } while (atomic_read(&dump_lock) != -1);
 		goto retry;
 	}