diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 76dc0b19139d..2ece7d67704f 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -9287,6 +9287,14 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 			hdr->b_l2hdr.b_hits = 0;
 			hdr->b_l2hdr.b_arcs_state =
 			    hdr->b_l1hdr.b_state->arcs_state;
+			arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR |
+			    ARC_FLAG_L2_WRITING);
+
+			(void) zfs_refcount_add_many(&dev->l2ad_alloc,
+			    arc_hdr_size(hdr), hdr);
+			l2arc_hdr_arcstats_increment(hdr);
+			vdev_space_update(dev->l2ad_vdev, asize, 0, 0);
+
 			mutex_enter(&dev->l2ad_mtx);
 			if (pio == NULL) {
 				/*
@@ -9298,12 +9306,6 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 			}
 			list_insert_head(&dev->l2ad_buflist, hdr);
 			mutex_exit(&dev->l2ad_mtx);
-			arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR |
-			    ARC_FLAG_L2_WRITING);
-
-			(void) zfs_refcount_add_many(&dev->l2ad_alloc,
-			    arc_hdr_size(hdr), hdr);
-			l2arc_hdr_arcstats_increment(hdr);
 
 			boolean_t commit = l2arc_log_blk_insert(dev, hdr);
 			mutex_exit(hash_lock);
@@ -9333,7 +9335,6 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 			write_psize += psize;
 			write_asize += asize;
 			dev->l2ad_hand += asize;
-			vdev_space_update(dev->l2ad_vdev, asize, 0, 0);
 
 			if (commit) {
 				/* l2ad_hand will be adjusted inside. */
@@ -10585,6 +10586,8 @@ l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb)
 	(void) zio_nowait(wzio);
 
 	dev->l2ad_hand += asize;
+	vdev_space_update(dev->l2ad_vdev, asize, 0, 0);
+
 	/*
 	 * Include the committed log block's pointer  in the list of pointers
 	 * to log blocks present in the L2ARC device.
@@ -10598,7 +10601,6 @@ l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb)
 	zfs_refcount_add_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf);
 	zfs_refcount_add(&dev->l2ad_lb_count, lb_ptr_buf);
 	mutex_exit(&dev->l2ad_mtx);
-	vdev_space_update(dev->l2ad_vdev, asize, 0, 0);
 
 	/* bump the kstats */
 	ARCSTAT_INCR(arcstat_l2_write_bytes, asize);
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index 2248f644bee7..4712addf81be 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -68,6 +68,7 @@
 #include <sys/zio_compress.h>
 #include <zfs_fletcher.h>
 #include <sys/zio_checksum.h>
+#include <sys/brt.h>
 
 /*
  * The SPA supports block sizes up to 16MB.  However, very large blocks
@@ -289,8 +290,26 @@ dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
 	if (BP_GET_LOGICAL_BIRTH(bp) > dsl_dataset_phys(ds)->ds_prev_snap_txg) {
 		int64_t delta;
 
-		dprintf_bp(bp, "freeing ds=%llu", (u_longlong_t)ds->ds_object);
-		dsl_free(tx->tx_pool, tx->tx_txg, bp);
+		/*
+		 * Put blocks that would create IO on the pool's deadlist for
+		 * dsl_process_async_destroys() to find. This is to prevent
+		 * zio_free() from creating a ZIO_TYPE_FREE IO for them, which
+		 * are very heavy and can lead to out-of-memory conditions if
+		 * something tries to free millions of blocks on the same txg.
+		 */
+		boolean_t defer = spa_version(spa) >= SPA_VERSION_DEADLISTS &&
+		    (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) ||
+		    brt_maybe_exists(spa, bp));
+
+		if (defer) {
+			dprintf_bp(bp, "putting on free list: %s", "");
+			bpobj_enqueue(&ds->ds_dir->dd_pool->dp_free_bpobj,
+			    bp, B_FALSE, tx);
+		} else {
+			dprintf_bp(bp, "freeing ds=%llu",
+			    (u_longlong_t)ds->ds_object);
+			dsl_free(tx->tx_pool, tx->tx_txg, bp);
+		}
 
 		mutex_enter(&ds->ds_lock);
 		ASSERT(dsl_dataset_phys(ds)->ds_unique_bytes >= used ||
@@ -298,9 +317,14 @@ dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
 		delta = parent_delta(ds, -used);
 		dsl_dataset_phys(ds)->ds_unique_bytes -= used;
 		mutex_exit(&ds->ds_lock);
+
 		dsl_dir_diduse_transfer_space(ds->ds_dir,
 		    delta, -compressed, -uncompressed, -used,
 		    DD_USED_REFRSRV, DD_USED_HEAD, tx);
+
+		if (defer)
+			dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
+			    DD_USED_HEAD, used, compressed, uncompressed, tx);
 	} else {
 		dprintf_bp(bp, "putting on dead list: %s", "");
 		if (async) {