Index: sys/kern/subr_epoch.c
===================================================================
--- sys/kern/subr_epoch.c
+++ sys/kern/subr_epoch.c
@@ -610,8 +610,8 @@
 	KASSERT(!in_epoch(epoch), ("epoch_wait_preempt() called in the middle "
 	    "of an epoch section of the same epoch"));
 #endif
-	thread_lock(td);
 	DROP_GIANT();
+	thread_lock(td);
 
 	old_cpu = PCPU_GET(cpuid);
 	old_pinned = td->td_pinned;