Index: sys/kern/subr_epoch.c
===================================================================
--- sys/kern/subr_epoch.c	(revision 336962)
+++ sys/kern/subr_epoch.c	(working copy)
@@ -232,33 +232,14 @@
 	struct epoch_thread *tdwait;
 	struct turnstile *ts;
 	struct lock_object *lock;
-	int spincount, gen;
 	int locksheld __unused;
 
 	record = __containerof(cr, struct epoch_record, er_record);
 	td = curthread;
 	locksheld = td->td_locks;
-	spincount = 0;
 	counter_u64_add(block_count, 1);
 	if (record->er_cpuid != curcpu) {
 		/*
-		 * If the head of the list is running, we can wait for it
-		 * to remove itself from the list and thus save us the
-		 * overhead of a migration
-		 */
-		if ((tdwait = TAILQ_FIRST(&record->er_tdlist)) != NULL &&
-		    TD_IS_RUNNING(tdwait->et_td)) {
-			gen = record->er_gen;
-			thread_unlock(td);
-			do {
-				cpu_spinwait();
-			} while (tdwait == TAILQ_FIRST(&record->er_tdlist) &&
-			    gen == record->er_gen && TD_IS_RUNNING(tdwait->et_td) &&
-			    spincount++ < MAX_ADAPTIVE_SPIN);
-			thread_lock(td);
-			return;
-		}
-		/*
 		 * Being on the same CPU as that of the record on which
 		 * we need to wait allows us access to the thread
 		 * list associated with that CPU. We can then examine the