XPK Start: Sun Apr 19 09:51:18 UTC 2026 2026-04-19 09:51:22.819537: E external/local_xla/xla/stream_executor/cuda/cuda_fft.cc:467] Unable to register cuFFT factory: Attempting to register factory for plugin cuFFT when one has already been registered WARNING: All log messages before absl::InitializeLog() is called are written to STDERR E0000 00:00:1776592282.833152 10 cuda_dnn.cc:8579] Unable to register cuDNN factory: Attempting to register factory for plugin cuDNN when one has already been registered E0000 00:00:1776592282.836935 10 cuda_blas.cc:1407] Unable to register cuBLAS factory: Attempting to register factory for plugin cuBLAS when one has already been registered W0000 00:00:1776592282.848473 10 computation_placer.cc:177] computation placer already registered. Please check linkage and avoid linking the same target more than once. W0000 00:00:1776592282.848494 10 computation_placer.cc:177] computation placer already registered. Please check linkage and avoid linking the same target more than once. W0000 00:00:1776592282.848496 10 computation_placer.cc:177] computation placer already registered. Please check linkage and avoid linking the same target more than once. W0000 00:00:1776592282.848498 10 computation_placer.cc:177] computation placer already registered. Please check linkage and avoid linking the same target more than once. 2026-04-19 09:51:41.925454: E external/local_xla/xla/stream_executor/cuda/cuda_platform.cc:51] failed call to cuInit: INTERNAL: CUDA error: Failed call to cuInit: UNKNOWN ERROR (303) I0419 09:51:42.445533 135892575229760 max_utils.py:273] Attempting to initialize the jax distributed system... INFO:2026-04-19 09:51:51,485:jax._src.distributed:140: Starting JAX distributed service on [::]:8482 I0419 09:51:51.485656 135892575229760 distributed.py:140] Starting JAX distributed service on [::]:8482 INFO:2026-04-19 09:51:51,488:jax._src.distributed:157: Connecting to JAX distributed service on mt-14-async-ckpt-false--k4gvr-slice-job-0-0.mt-14-async-ckpt-false--k4gvr:8482 I0419 09:51:51.488027 135892575229760 distributed.py:157] Connecting to JAX distributed service on mt-14-async-ckpt-false--k4gvr-slice-job-0-0.mt-14-async-ckpt-false--k4gvr:8482 I0419 09:51:52.546146 135892575229760 max_utils.py:284] Jax distributed system initialized! I0419 09:51:59.494078 135892575229760 max_utils.py:800] System Information: Jax Version: 0.8.1 I0419 09:51:59.494184 135892575229760 max_utils.py:801] System Information: Jaxlib Version: 0.8.1 I0419 09:51:59.494224 135892575229760 max_utils.py:802] System Information: Jax Backend: PJRT C API TFRT TPU v6 lite Built on Nov 12 2025 14:16:36 (1762985796) cl/831091709 I0419 09:51:59.494260 135892575229760 train_utils.py:347] WARNING: Sequence packing is essentially ignored for synthetic data. Please use a real dataset to use sequence packing. I0419 09:52:00.109825 135892575229760 maxtext_utils.py:1398] Num_devices: 32, shape (1, 1, 1, 32, 1, 1, 1, 1, 1, 1, 1, 1, 1) I0419 09:52:00.110136 135892575229760 checkpointing.py:677] Setting up checkpoint logger... I0419 09:52:00.110193 135892575229760 checkpointing.py:233] Creating checkpoint manager with ocdbt=True and zarr3=True I0419 09:52:00.110239 135892575229760 pytree_checkpoint_handler.py:589] save_device_host_concurrent_bytes=None I0419 09:52:00.110582 135892575229760 base_pytree_checkpoint_handler.py:415] Created BasePyTreeCheckpointHandler: use_ocdbt=True, use_zarr3=True, pytree_metadata_options=PyTreeMetadataOptions(support_rich_types=False), array_metadata_store=<orbax.checkpoint._src.metadata.array_metadata_store.Store object at 0x7b976b579010>, enable_pinned_host_transfer=False, save_concurrent_bytes: 96000000000 (89.4 GiB), restore_concurrent_bytes: 96000000000 (89.4 GiB) I0419 09:52:01.377645 135892575229760 checkpointing.py:265] Enabling policy for fixed interval checkpointing. I0419 09:52:01.377884 135892575229760 checkpoint_manager.py:709] [process=4][thread=MainThread] CheckpointManager init: checkpointers=None, item_names=('items',), item_handlers={'items': <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7b962f556900>}, handler_registry=None I0419 09:52:01.378194 135892575229760 composite_checkpoint_handler.py:237] Deferred registration for item: "items". Adding handler `<orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7b962f556900>` for item "items" and save args `<class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeSaveArgs'>` and restore args `<class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>` to `_handler_registry`. I0419 09:52:01.378249 135892575229760 composite_checkpoint_handler.py:237] Deferred registration for item: "metrics". Adding handler `<orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7b844ea66cc0>` for item "metrics" and save args `<class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>` and restore args `<class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>` to `_handler_registry`. I0419 09:52:01.378286 135892575229760 composite_checkpoint_handler.py:505] Initialized registry DefaultCheckpointHandlerRegistry({('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeSaveArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7b962f556900>, ('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7b962f556900>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7b844ea66cc0>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7b844ea66cc0>}). I0419 09:52:01.380901 135892575229760 abstract_checkpointer.py:35] orbax-checkpoint version: 0.11.33 I0419 09:52:02.918439 135772229330688 checkpoint.py:228] Read Metadata={'item_handlers': {'items': 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler'}, 'metrics': {}, 'performance_metrics': {}, 'init_timestamp_nsecs': 1776592152606638458, 'commit_timestamp_nsecs': 1776592201624929305, 'custom_metadata': {}} from gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/9/_CHECKPOINT_METADATA I0419 09:52:03.159068 135772229330688 checkpoint_manager.py:1877] Missing metrics for step 9 I0419 09:52:03.571843 135892575229760 checkpoint_manager.py:1818] Found 3 checkpoint steps in gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints I0419 09:52:04.440682 135892575229760 checkpoint_manager.py:929] [process=4][thread=MainThread] CheckpointManager created, primary_host=0, CheckpointManagerOptions=CheckpointManagerOptions(save_interval_steps=1, max_to_keep=None, keep_time_interval=None, keep_period=None, should_keep_fn=None, best_fn=None, best_mode='max', keep_checkpoints_without_metrics=True, step_prefix=None, step_format_fixed_length=None, step_name_format=None, create=True, cleanup_tmp_directories=False, save_on_steps=frozenset(), single_host_load_and_broadcast=False, todelete_subdir=None, todelete_full_path=None, enable_background_delete=False, read_only=False, enable_async_checkpointing=False, async_options=None, multiprocessing_options=MultiprocessingOptions(primary_host=0, active_processes=None, barrier_sync_key_prefix=None), should_save_fn=None, file_options=FileOptions(path_permission_mode=None), save_root_metadata=True, temporary_path_class=None, save_decision_policy=FixedIntervalPolicy(interval=5), preservation_policy=LatestN(n=None), prevent_write_metrics=False, enable_should_save_is_saving_in_progress_check=True, enable_per_process_directory_creation=False, lightweight_initialize=False), root_directory=gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints: <orbax.checkpoint.checkpoint_manager.CheckpointManager object at 0x7b844ea64d10> I0419 09:52:04.440874 135892575229760 checkpointing.py:301] Checkpoint manager created! I0419 09:52:05.323335 135892575229760 nnx_wrappers.py:453] Unknown Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_norm_length', 'activation_embed'). I0419 09:52:05.323438 135892575229760 nnx_wrappers.py:453] Unknown Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 09:52:05.694107 135892575229760 attentions.py:1084] attentions/inputs_q Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0419 09:52:05.694209 135892575229760 attentions.py:1084] attentions/inputs_q Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 09:52:05.709690 135892575229760 attentions.py:1085] attentions/inputs_kv Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0419 09:52:05.709751 135892575229760 attentions.py:1085] attentions/inputs_kv Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 09:52:05.732765 135892575229760 attentions.py:1150] attentions/query Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 09:52:05.732836 135892575229760 attentions.py:1150] attentions/query Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 09:52:05.748466 135892575229760 attentions.py:1151] attentions/key Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 09:52:05.748524 135892575229760 attentions.py:1151] attentions/key Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 09:52:05.764140 135892575229760 attentions.py:1152] attentions/value Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 09:52:05.764201 135892575229760 attentions.py:1152] attentions/value Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 09:52:05.787839 135892575229760 attentions.py:1193] attentions/out Logical: bfloat16[32,2048,16,128].................................... ('activation_batch', 'activation_attn_length', 'activation_heads', 'activation_kv'). I0419 09:52:05.787914 135892575229760 attentions.py:1193] attentions/out Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 09:52:05.807163 135892575229760 linears.py:525] linears/x Logical: bfloat16[32,2048,7168]...................................... ('activation_batch', 'activation_length', 'activation_mlp'). I0419 09:52:05.807226 135892575229760 linears.py:525] linears/x Physical: bfloat16[32,2048,7168]...................................... ('fsdp', None, None). I0419 09:52:05.996094 135892575229760 checkpointing.py:577] checkpoint manager exists so trying to load this run's existing checkpoint I0419 09:52:05.996204 135892575229760 checkpointing.py:581] restoring from this run's directory step 9 I0419 09:52:06.486171 135892575229760 checkpointer.py:304] Restoring checkpoint from gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/9. I0419 09:52:09.155563 1411 google_auth_provider.cc:181] Running on GCE, using service account 562977990677-compute@developer.gserviceaccount.com I0419 09:52:16.566671 135892575229760 jax_array_handlers.py:837] [process=4] /jax/orbax/read/worker/io/requested throughput: 213.080 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 7.416355848312378 s) (per-host) I0419 09:52:16.579878 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/read/gbytes_per_sec: 191.913 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 8.246417760848999 s) (per-host) I0419 09:52:16.597291 135892575229760 checkpointer.py:318] Finished restoring checkpoint in 10.35 seconds from gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/9. I0419 09:52:16.597404 135892575229760 standard_logger.py:34] {'step': 9, 'event_type': 'restore', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints', 'checkpointer_start_time': 1776592326.2454991, 'checkpointer_duration_secs': 10.351876020431519, 'checkpoint_manager_start_time': 1776592325.9964452, 'checkpoint_manager_duration_secs': 10.600931406021118} fsdp: 32 I0419 09:52:16.991726 135892575229760 maxtext_utils.py:1501] params/params/decoder/decoder_norm/scale Shape: float32[2048] Logical: PartitionSpec('norm',) Physical: (None,) I0419 09:52:16.991877 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/mlp/wi_0/kernel Shape: float32[2048,16,7168] Logical: PartitionSpec('embed', 'layers', 'mlp') Physical: ('fsdp', None, None) I0419 09:52:16.991955 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/mlp/wi_1/kernel Shape: float32[2048,16,7168] Logical: PartitionSpec('embed', 'layers', 'mlp') Physical: ('fsdp', None, None) I0419 09:52:16.992049 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/mlp/wo/kernel Shape: float32[7168,16,2048] Logical: PartitionSpec('mlp', 'layers', 'embed') Physical: (None, None, 'fsdp') I0419 09:52:16.992142 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/post_self_attention_layer_norm/scale Shape: float32[2048,16] Logical: PartitionSpec('norm', 'layers') Physical: (None, None) I0419 09:52:16.992203 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/pre_self_attention_layer_norm/scale Shape: float32[2048,16] Logical: PartitionSpec('norm', 'layers') Physical: (None, None) I0419 09:52:16.992264 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/self_attention/key/kernel Shape: float32[2048,16,16,128] Logical: PartitionSpec('embed', 'layers', 'kv_heads', 'kv_head_dim') Physical: ('fsdp', None, None, None) I0419 09:52:16.992319 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/self_attention/out/kernel Shape: float32[16,16,128,2048] Logical: PartitionSpec('heads', 'layers', 'kv', 'embed') Physical: (None, None, None, 'fsdp') I0419 09:52:16.992383 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/self_attention/query/kernel Shape: float32[2048,16,16,128] Logical: PartitionSpec('embed', 'layers', 'q_heads', 'kv') Physical: ('fsdp', None, None, None) I0419 09:52:16.992442 135892575229760 maxtext_utils.py:1501] params/params/decoder/layers/self_attention/value/kernel Shape: float32[2048,16,16,128] Logical: PartitionSpec('embed', 'layers', 'kv_heads', 'kv_head_dim') Physical: ('fsdp', None, None, None) I0419 09:52:16.992514 135892575229760 maxtext_utils.py:1501] params/params/decoder/logits_dense/kernel Shape: float32[2048,32000] Logical: PartitionSpec('embed', 'vocab') Physical: ('fsdp', None) I0419 09:52:16.992585 135892575229760 maxtext_utils.py:1501] params/params/token_embedder/embedding Shape: float32[32000,2048] Logical: PartitionSpec('vocab', 'embed') Physical: (None, 'fsdp') I0419 09:52:17.485352 135892575229760 train.py:156] train/xent Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0419 09:52:17.485444 135892575229760 train.py:156] train/xent Physical: float32[32,2048]............................................ ('fsdp', None). I0419 09:52:17.500046 135892575229760 train.py:163] train/z_loss Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0419 09:52:17.500101 135892575229760 train.py:163] train/z_loss Physical: float32[32,2048]............................................ ('fsdp', None). I0419 09:52:28.336060 135892575229760 max_utils.py:791] Total memory size: 1.5 GB, Output size: 0.4 GB, Temp size: 1.1 GB, Argument size: 0.4 GB, Host temp size: 0.0 GB. I0419 09:52:28.336897 135892575229760 metric_logger.py:289] number parameters: 1.104 billion I0419 09:52:39.481808 135892575229760 checkpointing.py:772] Waiting for step 10 to finish before checkpoint... I0419 09:52:39.635855 135892575229760 checkpointing.py:776] Waited 0.15403246879577637 seconds for step 10 to finish before starting checkpointing. I0419 09:52:39.638224 135892575229760 checkpoint_manager.py:2013] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 09:52:39.640354 135892575229760 checkpoint_manager.py:1518] [process=4] Saving checkpoint at step 10 I0419 09:52:39.641738 135892575229760 checkpointer.py:241] [process=4] Started saving checkpoint to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/10. I0419 09:52:43.319100 135892575229760 signaling_client.py:364] Using JaxDistributedSignalingClient I0419 09:52:43.320335 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=1] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:52:45.346522 135892575229760 jax_array_handlers.py:358] Scheduling D2H of 39 prioritized jax.Array. I0419 09:52:45.346628 135892575229760 replica_slices.py:424] Transferring arrays to host memory with options: use_replica_parallel=True, min_slice_bytes_for_replica_parallel=None, max_replicas_for_replica_parallel=None, enable_pinned_host_transfer=False I0419 09:52:45.596056 135892575229760 base_pytree_checkpoint_handler.py:153] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.250603s I0419 09:52:45.596245 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/blocking_gbytes_per_sec: 3.005 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.5133872032165527 s) (per-host) I0419 09:52:45.596303 135892575229760 base_pytree_checkpoint_handler.py:737] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.513456s (batch_requests_ready=0.260818s, total_serialization_initiated=0.252560s, others=0.000079s) I0419 09:52:45.596406 135892575229760 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 2.277392s (all_items=0.000033s, per_item={'items': '0.00003314'}, temp_paths=2.277359) I0419 09:52:45.596464 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=1] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:52:45.596519 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=1] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:52:47.983397 135767934363392 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/10/items/array_metadatas/process_4 I0419 09:53:24.094480 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/gbytes_per_sec: 40.490 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 39.01160264015198 s) (per-host) I0419 09:53:33.601484 135892575229760 checkpointer.py:290] Finished synchronous save in 53.96 seconds to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/10 I0419 09:53:33.604342 135892575229760 checkpoint_manager.py:2133] [process=4][thread=MainThread][step=10] CheckpointManager Save Finalize is syncing with other hosts... I0419 09:53:33.606053 135892575229760 checkpoint_manager.py:2142] [process=4][thread=MainThread][step=10] CheckpointManager Save Finalize is done on all hosts. I0419 09:53:33.606104 135892575229760 checkpoint_manager.py:1587] [process=4][thread=MainThread][step=10] Finished synchronous save. I0419 09:53:33.606155 135892575229760 standard_logger.py:34] {'step': 10, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776592359.6382055, 'wait_for_prev_duration_secs': 6.389617919921875e-05, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776592359.6403933, 'checkpointer_blocking_duration_secs': 53.96120882034302, 'get_old_steps_start_time': 1776592413.6016247, 'get_old_steps_duration_secs': 2.5987625122070312e-05, 'checkpoint_manager_blocking_start_time': 1776592359.6364036, 'checkpoint_manager_blocking_duration_secs': 53.969724893569946} I0419 09:53:33.606239 135892575229760 checkpointing.py:410] Saved a checkpoint at step 10. I0419 09:53:33.606283 135892575229760 max_utils.py:750] Memstats: After params initialized: I0419 09:53:33.606328 135892575229760 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_16(process=4,(0,4,0,0)) I0419 09:53:33.606358 135892575229760 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_17(process=4,(1,4,0,0)) I0419 09:53:33.606385 135892575229760 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_20(process=4,(0,5,0,0)) I0419 09:53:33.606410 135892575229760 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_21(process=4,(1,5,0,0)) I0419 09:53:33.879602 135892575229760 metric_logger.py:185] completed step: 10, seconds: 11.145, TFLOP/s/device: 1.219, Tokens/s/device: 183.763, total_weights: 65536, loss: 6.833 I0419 09:53:34.038663 135892575229760 metric_logger.py:185] completed step: 11, seconds: 54.379, TFLOP/s/device: 0.250, Tokens/s/device: 37.662, total_weights: 65536, loss: 6.528 I0419 09:53:34.186382 135892575229760 metric_logger.py:185] completed step: 12, seconds: 0.030, TFLOP/s/device: 458.575, Tokens/s/device: 69121.469, total_weights: 65536, loss: 6.265 I0419 09:53:34.333872 135892575229760 metric_logger.py:185] completed step: 13, seconds: 0.153, TFLOP/s/device: 88.859, Tokens/s/device: 13393.850, total_weights: 65536, loss: 6.045 I0419 09:53:34.338555 135892575229760 checkpointing.py:772] Waiting for step 15 to finish before checkpoint... I0419 09:53:34.628549 135892575229760 checkpointing.py:776] Waited 0.28995847702026367 seconds for step 15 to finish before starting checkpointing. I0419 09:53:34.631290 135892575229760 checkpoint_manager.py:2013] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 09:53:34.632888 135892575229760 checkpoint_manager.py:1518] [process=4] Saving checkpoint at step 15 I0419 09:53:34.634609 135892575229760 checkpointer.py:241] [process=4] Started saving checkpoint to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/15. I0419 09:53:37.877362 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=2] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:53:39.499358 135892575229760 jax_array_handlers.py:358] Scheduling D2H of 39 prioritized jax.Array. I0419 09:53:39.499463 135892575229760 replica_slices.py:424] Transferring arrays to host memory with options: use_replica_parallel=True, min_slice_bytes_for_replica_parallel=None, max_replicas_for_replica_parallel=None, enable_pinned_host_transfer=False I0419 09:53:39.545437 135892575229760 base_pytree_checkpoint_handler.py:153] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.047056s I0419 09:53:39.545612 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/blocking_gbytes_per_sec: 5.121 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.30121850967407227 s) (per-host) I0419 09:53:39.545667 135892575229760 base_pytree_checkpoint_handler.py:737] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.301283s (batch_requests_ready=0.252169s, total_serialization_initiated=0.049042s, others=0.000071s) I0419 09:53:39.545772 135892575229760 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 1.669601s (all_items=0.000027s, per_item={'items': '0.00002670'}, temp_paths=1.669575) I0419 09:53:39.545813 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=2] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:53:39.545850 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=2] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:53:41.378523 135759839336192 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/15/items/array_metadatas/process_4 I0419 09:54:18.242290 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/gbytes_per_sec: 40.505 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 38.99785757064819 s) (per-host) I0419 09:54:28.122307 135892575229760 checkpointer.py:290] Finished synchronous save in 53.49 seconds to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/15 I0419 09:54:28.124181 135892575229760 checkpoint_manager.py:2133] [process=4][thread=MainThread][step=15] CheckpointManager Save Finalize is syncing with other hosts... I0419 09:54:28.126041 135892575229760 checkpoint_manager.py:2142] [process=4][thread=MainThread][step=15] CheckpointManager Save Finalize is done on all hosts. I0419 09:54:28.126092 135892575229760 checkpoint_manager.py:1587] [process=4][thread=MainThread][step=15] Finished synchronous save. I0419 09:54:28.126143 135892575229760 standard_logger.py:34] {'step': 15, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776592414.6312702, 'wait_for_prev_duration_secs': 6.604194641113281e-05, 'time_between_consecutive_saves_sec': 1.025177001953125, 'checkpointer_blocking_start_time': 1776592414.6329262, 'checkpointer_blocking_duration_secs': 53.48950123786926, 'get_old_steps_start_time': 1776592468.122448, 'get_old_steps_duration_secs': 2.7179718017578125e-05, 'checkpoint_manager_blocking_start_time': 1776592414.6292338, 'checkpoint_manager_blocking_duration_secs': 53.49688386917114} I0419 09:54:28.126231 135892575229760 checkpointing.py:410] Saved a checkpoint at step 15. I0419 09:54:28.126724 135892575229760 metric_logger.py:185] completed step: 14, seconds: 0.148, TFLOP/s/device: 91.981, Tokens/s/device: 13864.443, total_weights: 65536, loss: 5.864 I0419 09:54:28.149590 135892575229760 metric_logger.py:185] completed step: 15, seconds: 0.148, TFLOP/s/device: 92.076, Tokens/s/device: 13878.724, total_weights: 65536, loss: 5.719 I0419 09:54:46.374958 135892575229760 metric_logger.py:185] completed step: 16, seconds: 53.793, TFLOP/s/device: 0.253, Tokens/s/device: 38.072, total_weights: 65536, loss: 5.605 I0419 09:54:46.522558 135892575229760 metric_logger.py:185] completed step: 17, seconds: 18.097, TFLOP/s/device: 0.751, Tokens/s/device: 113.171, total_weights: 65536, loss: 5.517 I0419 09:54:46.670050 135892575229760 metric_logger.py:185] completed step: 18, seconds: 0.152, TFLOP/s/device: 89.434, Tokens/s/device: 13480.424, total_weights: 65536, loss: 5.448 I0419 09:54:46.817091 135892575229760 checkpointing.py:772] Waiting for step 19 to finish before checkpoint... I0419 09:54:46.817754 135892575229760 checkpointing.py:776] Waited 0.0006823539733886719 seconds for step 19 to finish before starting checkpointing. I0419 09:54:46.819932 135892575229760 checkpoint_manager.py:2013] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 09:54:46.821915 135892575229760 checkpoint_manager.py:1518] [process=4] Saving checkpoint at step 19 I0419 09:54:46.823273 135892575229760 checkpointer.py:241] [process=4] Started saving checkpoint to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/19. I0419 09:54:50.080650 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=3] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:54:51.697154 135892575229760 jax_array_handlers.py:358] Scheduling D2H of 39 prioritized jax.Array. I0419 09:54:51.697258 135892575229760 replica_slices.py:424] Transferring arrays to host memory with options: use_replica_parallel=True, min_slice_bytes_for_replica_parallel=None, max_replicas_for_replica_parallel=None, enable_pinned_host_transfer=False I0419 09:54:51.739495 135892575229760 base_pytree_checkpoint_handler.py:153] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.043479s I0419 09:54:51.739677 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/blocking_gbytes_per_sec: 5.214 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.29587841033935547 s) (per-host) I0419 09:54:51.739733 135892575229760 base_pytree_checkpoint_handler.py:737] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.295943s (batch_requests_ready=0.250308s, total_serialization_initiated=0.045565s, others=0.000070s) I0419 09:54:51.739830 135892575229760 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 1.660414s (all_items=0.000023s, per_item={'items': '0.00002289'}, temp_paths=1.660392) I0419 09:54:51.739874 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=3] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:54:51.739909 135892575229760 future.py:363] [process=4][thread=MainThread][operation_id=3] _SignalingThread.join() waiting for signals ([]) blocking the main thread will slow down blocking save times. This is likely due to main thread calling result() on a CommitFuture. I0419 09:54:54.143064 135772187367168 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/19/items/array_metadatas/process_4 I0419 09:55:30.381815 135892575229760 base_pytree_checkpoint_handler.py:129] [process=4] /jax/checkpoint/write/gbytes_per_sec: 40.567 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 38.93797540664673 s) (per-host) I0419 09:55:39.917601 135892575229760 checkpointer.py:290] Finished synchronous save in 53.10 seconds to gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints/19 I0419 09:55:39.920611 135892575229760 checkpoint_manager.py:2133] [process=4][thread=MainThread][step=19] CheckpointManager Save Finalize is syncing with other hosts... I0419 09:55:39.922508 135892575229760 checkpoint_manager.py:2142] [process=4][thread=MainThread][step=19] CheckpointManager Save Finalize is done on all hosts. I0419 09:55:39.922558 135892575229760 checkpoint_manager.py:1587] [process=4][thread=MainThread][step=19] Finished synchronous save. I0419 09:55:39.922608 135892575229760 standard_logger.py:34] {'step': 19, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_test_pipeline_scan_nnx_20260419_085454/linen_xpk_test_pipeline_scan_nnx_20260419_085454_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776592486.8199158, 'wait_for_prev_duration_secs': 7.724761962890625e-05, 'time_between_consecutive_saves_sec': 18.693835258483887, 'checkpointer_blocking_start_time': 1776592486.821968, 'checkpointer_blocking_duration_secs': 53.09574818611145, 'get_old_steps_start_time': 1776592539.9177296, 'get_old_steps_duration_secs': 2.002716064453125e-05, 'checkpoint_manager_blocking_start_time': 1776592486.8180168, 'checkpoint_manager_blocking_duration_secs': 53.10456657409668} I0419 09:55:39.922692 135892575229760 checkpointing.py:410] Saved a checkpoint at step 19. I0419 09:55:39.922725 135892575229760 checkpoint_manager.py:2013] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 09:55:39.922755 135892575229760 checkpoint_manager.py:2013] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 09:55:39.923154 135892575229760 metric_logger.py:185] completed step: 19, seconds: 0.148, TFLOP/s/device: 91.985, Tokens/s/device: 13865.006, total_weights: 65536, loss: 5.391 Per train step: Total TFLOPs: 13.59 split as 93.93% learnable weight flops and 6.07% attention flops XPK End: Sun Apr 19 09:55:49 UTC 2026 EXIT_CODE=0