Index: zio.c
===================================================================
--- zio.c	(revision 253644)
+++ zio.c	(working copy)
@@ -770,7 +770,7 @@ zio_free(spa_t *spa, uint64_t txg, const blkptr_t
 	 * DEDUP), can be processed immediately.  Otherwise, put them on the
 	 * in-memory list for later processing.
 	 */
-	if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) ||
+	if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) ||
 	    txg != spa->spa_syncing_txg ||
 	    spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) {
 		bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
@@ -797,12 +797,15 @@ zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg
 	metaslab_check_free(spa, bp);
 	arc_freed(spa, bp);
 
+	if (zfs_trim_enabled)
+		stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START |
+		    ZIO_STAGE_VDEV_IO_ASSESS;
 	/*
 	 * GANG and DEDUP blocks can induce a read (for the gang block header,
 	 * or the DDT), so issue them asynchronously so that this thread is
 	 * not tied up.
 	 */
-	if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp))
+	else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp))
 		stage |= ZIO_STAGE_ISSUE_ASYNC;
 
 	zio = zio_create(pio, spa, txg, bp, NULL, size,
Index: sys/zio_impl.h
===================================================================
--- sys/zio_impl.h	(revision 253644)
+++ sys/zio_impl.h	(working copy)
@@ -213,9 +213,7 @@ enum zio_stage {
 #define	ZIO_FREE_PIPELINE			\
 	(ZIO_INTERLOCK_STAGES |			\
 	ZIO_STAGE_FREE_BP_INIT |		\
-	ZIO_STAGE_DVA_FREE |			\
-	ZIO_STAGE_VDEV_IO_START |		\
-	ZIO_STAGE_VDEV_IO_ASSESS)
+	ZIO_STAGE_DVA_FREE)
 
 #define	ZIO_DDT_FREE_PIPELINE			\
 	(ZIO_INTERLOCK_STAGES |			\