X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=lib%2Fdump_stack.c;h=287ea178f0fa951a225032a4ebc84030cca5cdcb;hb=7e065e0242fc285cc29c5ea4a80d108262af5148;hp=625375e7f11f98f2468002772265e30e753345fb;hpb=4d4dfc1caaea95e18223f48f5c4d49f898502941;p=people%2Farne_f%2Fkernel.git

diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 625375e7f11f9..287ea178f0fa9 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Provide a default dump_stack() function for architectures
  * which don't implement their own.
@@ -45,7 +46,12 @@ 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;
 	}