XPK Start: Sun Apr 19 19:03:12 UTC 2026 PyTorch was not found. Models won't be available and only tokenizers, configuration and file/data utilities can be used. 2026-04-19 19:03:36.678136: 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 19:03:36.858810 140068444120896 max_utils.py:273] Attempting to initialize the jax distributed system... I0419 19:03:45.898382 140068444120896 distributed.py:149] Starting JAX distributed service on [::]:8482 I0419 19:03:45.900706 140068444120896 distributed.py:172] Connecting to JAX distributed service on mt-14-async-ckpt-false--r0ne7-slice-job-0-0.mt-14-async-ckpt-false--r0ne7:8482 I0419 19:03:47.449541 140068444120896 max_utils.py:284] Jax distributed system initialized! I0419 19:03:52.584580 140068444120896 max_utils.py:800] System Information: Jax Version: 0.9.2 I0419 19:03:52.584682 140068444120896 max_utils.py:801] System Information: Jaxlib Version: 0.9.2 I0419 19:03:52.584721 140068444120896 max_utils.py:802] System Information: Jax Backend: PJRT C API TFRT TPU v6 lite Built on Mar 4 2026 11:32:08 (1772652728) cl/878335365 I0419 19:03:52.584755 140068444120896 train_utils.py:348] WARNING: Sequence packing is essentially ignored for synthetic data. Please use a real dataset to use sequence packing. I0419 19:03:53.288593 140068444120896 maxtext_utils.py:1551] Num_devices: 32, shape (1, 1, 1, 32, 1, 1, 1, 1, 1, 1, 1, 1, 1) I0419 19:03:53.288868 140068444120896 checkpointing.py:677] Setting up checkpoint logger... I0419 19:03:53.288920 140068444120896 checkpointing.py:233] Creating checkpoint manager with ocdbt=True and zarr3=True I0419 19:03:53.288963 140068444120896 pytree_checkpoint_handler.py:592] save_device_host_concurrent_bytes=None I0419 19:03:53.289302 140068444120896 base_pytree_checkpoint_handler.py:441] 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 0x7f6382248350>, enable_pinned_host_transfer=False, save_concurrent_bytes: 96000000000 (89.4 GiB), restore_concurrent_bytes: 96000000000 (89.4 GiB) I0419 19:03:56.644319 140068444120896 checkpointing.py:265] Enabling policy for fixed interval checkpointing. I0419 19:03:56.644571 140068444120896 checkpoint_manager.py:708] [process=6][thread=MainThread] CheckpointManager init: checkpointers=None, item_names=('items',), item_handlers={'items': <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7f4fd87ba270>}, handler_registry=None I0419 19:03:56.644811 140068444120896 composite_checkpoint_handler.py:237] Deferred registration for item: "items". Adding handler `<orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7f4fd87ba270>` 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 19:03:56.644860 140068444120896 composite_checkpoint_handler.py:237] Deferred registration for item: "metrics". Adding handler `<orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7f4fd841ecf0>` 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 19:03:56.644893 140068444120896 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 0x7f4fd87ba270>, ('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7f4fd87ba270>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7f4fd841ecf0>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7f4fd841ecf0>}). I0419 19:03:56.645202 140068444120896 abstract_checkpointer.py:35] orbax-checkpoint version: 0.11.34 I0419 19:03:57.886260 140068444120896 checkpoint_manager.py:1812] Found 0 checkpoint steps in gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints I0419 19:03:58.311348 140068444120896 checkpoint_manager.py:929] [process=6][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_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints: <orbax.checkpoint.checkpoint_manager.CheckpointManager object at 0x7f4fd84153a0> I0419 19:03:58.311564 140068444120896 checkpointing.py:301] Checkpoint manager created! I0419 19:03:59.244375 140068444120896 nnx_wrappers.py:437] Unknown Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_norm_length', 'activation_embed'). I0419 19:03:59.244495 140068444120896 nnx_wrappers.py:437] Unknown Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 19:03:59.625483 140068444120896 attentions.py:1088] attentions/inputs_q Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0419 19:03:59.625587 140068444120896 attentions.py:1088] attentions/inputs_q Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 19:03:59.641927 140068444120896 attentions.py:1089] attentions/inputs_kv Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0419 19:03:59.641987 140068444120896 attentions.py:1089] attentions/inputs_kv Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0419 19:03:59.665532 140068444120896 attentions.py:1154] attentions/query Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 19:03:59.665597 140068444120896 attentions.py:1154] attentions/query Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 19:03:59.681674 140068444120896 attentions.py:1155] attentions/key Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 19:03:59.681735 140068444120896 attentions.py:1155] attentions/key Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 19:03:59.697767 140068444120896 attentions.py:1156] attentions/value Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0419 19:03:59.697825 140068444120896 attentions.py:1156] attentions/value Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 19:03:59.722399 140068444120896 attentions.py:1197] attentions/out Logical: bfloat16[32,2048,16,128].................................... ('activation_batch', 'activation_attn_length', 'activation_heads', 'activation_kv'). I0419 19:03:59.722482 140068444120896 attentions.py:1197] attentions/out Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0419 19:03:59.743430 140068444120896 linears.py:525] linears/x Logical: bfloat16[32,2048,7168]...................................... ('activation_batch', 'activation_length', 'activation_mlp'). I0419 19:03:59.743497 140068444120896 linears.py:525] linears/x Physical: bfloat16[32,2048,7168]...................................... ('fsdp', None, None). I0419 19:03:59.961603 140068444120896 checkpointing.py:577] checkpoint manager exists so trying to load this run's existing checkpoint I0419 19:03:59.961718 140068444120896 checkpointing.py:665] No existing checkpoints found, not restoring checkpoint. fsdp: 32 I0419 19:04:01.387768 140068444120896 maxtext_utils.py:1654] params/params/decoder/decoder_norm/scale Shape: float32[2048] Logical: P('norm',) Physical: (None,) I0419 19:04:01.387892 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/mlp/wi_0/kernel Shape: float32[2048,16,7168] Logical: P('embed', 'layers', 'mlp') Physical: ('fsdp', None, None) I0419 19:04:01.387945 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/mlp/wi_1/kernel Shape: float32[2048,16,7168] Logical: P('embed', 'layers', 'mlp') Physical: ('fsdp', None, None) I0419 19:04:01.388002 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/mlp/wo/kernel Shape: float32[7168,16,2048] Logical: P('mlp', 'layers', 'embed') Physical: (None, None, 'fsdp') I0419 19:04:01.388054 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/post_self_attention_layer_norm/scale Shape: float32[2048,16] Logical: P('norm', 'layers') Physical: (None, None) I0419 19:04:01.388093 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/pre_self_attention_layer_norm/scale Shape: float32[2048,16] Logical: P('norm', 'layers') Physical: (None, None) I0419 19:04:01.388145 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/self_attention/key/kernel Shape: float32[2048,16,16,128] Logical: P('embed', 'layers', 'kv_heads', 'kv_head_dim') Physical: ('fsdp', None, None, None) I0419 19:04:01.388196 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/self_attention/out/kernel Shape: float32[16,16,128,2048] Logical: P('heads', 'layers', 'kv', 'embed') Physical: (None, None, None, 'fsdp') I0419 19:04:01.388235 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/self_attention/query/kernel Shape: float32[2048,16,16,128] Logical: P('embed', 'layers', 'q_heads', 'kv') Physical: ('fsdp', None, None, None) I0419 19:04:01.388271 140068444120896 maxtext_utils.py:1654] params/params/decoder/layers/self_attention/value/kernel Shape: float32[2048,16,16,128] Logical: P('embed', 'layers', 'kv_heads', 'kv_head_dim') Physical: ('fsdp', None, None, None) I0419 19:04:01.388319 140068444120896 maxtext_utils.py:1654] params/params/decoder/logits_dense/kernel Shape: float32[2048,32000] Logical: P('embed_vocab', 'vocab') Physical: ('fsdp', None) I0419 19:04:01.388372 140068444120896 maxtext_utils.py:1654] params/params/token_embedder/embedding Shape: float32[32000,2048] Logical: P('vocab', 'embed_vocab') Physical: (None, 'fsdp') I0419 19:04:01.878892 140068444120896 train.py:155] train/xent Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0419 19:04:01.878989 140068444120896 train.py:155] train/xent Physical: float32[32,2048]............................................ ('fsdp', None). I0419 19:04:01.894197 140068444120896 train.py:162] train/z_loss Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0419 19:04:01.894258 140068444120896 train.py:162] train/z_loss Physical: float32[32,2048]............................................ ('fsdp', None). I0419 19:04:12.973424 140068444120896 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 19:04:12.974232 140068444120896 metric_logger.py:301] number parameters: 1.104 billion I0419 19:04:24.284505 140068444120896 checkpointing.py:772] Waiting for step 0 to finish before checkpoint... I0419 19:04:24.437650 140068444120896 checkpointing.py:776] Waited 0.15313029289245605 seconds for step 0 to finish before starting checkpointing. I0419 19:04:24.440317 140068444120896 checkpoint_manager.py:2009] [process=6][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 19:04:24.442028 140068444120896 checkpoint_manager.py:1512] [process=6] Saving checkpoint at step 0 I0419 19:04:24.443556 140068444120896 event_tracking.py:70] [process=6] [sync] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/0. I0419 19:04:28.247519 140068444120896 signaling_client.py:364] Using JaxDistributedSignalingClient I0419 19:04:28.248834 140068444120896 future.py:372] [process=6][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 19:04:30.498142 140068444120896 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0419 19:04:30.498239 140068444120896 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 19:04:30.777089 140068444120896 base_pytree_checkpoint_handler.py:154] [process=6][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.279883s I0419 19:04:30.777272 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/blocking_gbytes_per_sec: 5.394 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.2859666347503662 s) (per-host) I0419 19:04:30.777327 140068444120896 base_pytree_checkpoint_handler.py:768] [process=6][thread=MainThread] Initiated Pytree async_save. Time taken: 0.286033s (batch_requests_ready=0.002667s, total_serialization_initiated=0.283291s, others=0.000075s) I0419 19:04:30.777448 140068444120896 composite_checkpoint_handler.py:715] [process=6][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 2.530057s (all_items=0.000032s, per_item={'items': '0.00003242'}, temp_paths=2.530025) I0419 19:04:30.777500 140068444120896 future.py:372] [process=6][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 19:04:30.777543 140068444120896 future.py:372] [process=6][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 19:04:30.789222 2746 google_auth_provider.cc:181] Running on GCE, using service account 562977990677-compute@developer.gserviceaccount.com I0419 19:04:33.183651 139940704810752 array_metadata_store.py:203] [process=6][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/0/items/array_metadatas/process_6 I0419 19:05:04.353106 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/gbytes_per_sec: 46.648 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 33.861762046813965 s) (per-host) I0419 19:05:10.426594 140068444120896 event_tracking.py:125] [process=6] [sync] Finished blocking save in 45.98 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/0. I0419 19:05:15.114984 140068444120896 event_tracking.py:138] [process=6] [sync] Finished save in 50.67 seconds @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/0 I0419 19:05:15.117008 140068444120896 checkpoint_manager.py:2137] [process=6][thread=MainThread][step=0] CheckpointManager Save Finalize is syncing with other hosts... I0419 19:05:15.118934 140068444120896 checkpoint_manager.py:2146] [process=6][thread=MainThread][step=0] CheckpointManager Save Finalize is done on all hosts. I0419 19:05:15.118984 140068444120896 checkpoint_manager.py:1581] [process=6][thread=MainThread][step=0] Finished synchronous save. I0419 19:05:15.119039 140068444120896 standard_logger.py:34] {'step': 0, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776625464.440299, 'wait_for_prev_duration_secs': 6.318092346191406e-05, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776625464.4420662, 'checkpointer_blocking_duration_secs': 50.67303800582886, 'get_old_steps_start_time': 1776625515.1151283, 'get_old_steps_duration_secs': 2.5033950805664062e-05, 'checkpoint_manager_blocking_start_time': 1776625464.438147, 'checkpoint_manager_blocking_duration_secs': 50.680864095687866} I0419 19:05:15.119128 140068444120896 checkpointing.py:410] Saved a checkpoint at step 0. I0419 19:05:15.119172 140068444120896 max_utils.py:750] Memstats: After params initialized: I0419 19:05:15.119216 140068444120896 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_24(process=6,(0,6,0,0)) I0419 19:05:15.119247 140068444120896 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_25(process=6,(1,6,0,0)) I0419 19:05:15.119273 140068444120896 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_28(process=6,(0,7,0,0)) I0419 19:05:15.119297 140068444120896 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_29(process=6,(1,7,0,0)) I0419 19:05:15.441688 140068444120896 metric_logger.py:196] completed step: 0, seconds: 11.310, TFLOP/s/device: 1.201, Tokens/s/device: 181.076, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52779.875 I0419 19:05:15.605532 140068444120896 metric_logger.py:196] completed step: 1, seconds: 51.141, TFLOP/s/device: 0.266, Tokens/s/device: 40.046, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52779.875 I0419 19:05:16.423252 140068444120896 metric_logger.py:196] completed step: 2, seconds: 0.031, TFLOP/s/device: 432.326, Tokens/s/device: 65164.821, total_weights: 65536, loss: 10.560, lm_loss: 10.560, perplexity: 38547.719 I0419 19:05:16.570599 140068444120896 metric_logger.py:196] completed step: 3, seconds: 0.818, TFLOP/s/device: 16.608, Tokens/s/device: 2503.404, total_weights: 65536, loss: 9.980, lm_loss: 9.980, perplexity: 21590.506 I0419 19:05:16.574991 140068444120896 checkpointing.py:772] Waiting for step 5 to finish before checkpoint... I0419 19:05:16.864863 140068444120896 checkpointing.py:776] Waited 0.28983473777770996 seconds for step 5 to finish before starting checkpointing. I0419 19:05:16.867947 140068444120896 checkpoint_manager.py:2009] [process=6][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 19:05:16.869562 140068444120896 checkpoint_manager.py:1512] [process=6] Saving checkpoint at step 5 I0419 19:05:16.871361 140068444120896 event_tracking.py:70] [process=6] [sync] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/5. I0419 19:05:20.199152 140068444120896 future.py:372] [process=6][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 19:05:22.020009 140068444120896 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0419 19:05:22.020105 140068444120896 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 19:05:22.062316 140068444120896 base_pytree_checkpoint_handler.py:154] [process=6][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.043578s I0419 19:05:22.062505 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/blocking_gbytes_per_sec: 32.598 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.047321319580078125 s) (per-host) I0419 19:05:22.062562 140068444120896 base_pytree_checkpoint_handler.py:768] [process=6][thread=MainThread] Initiated Pytree async_save. Time taken: 0.047388s (batch_requests_ready=0.001772s, total_serialization_initiated=0.045541s, others=0.000075s) I0419 19:05:22.062663 140068444120896 composite_checkpoint_handler.py:715] [process=6][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 1.864867s (all_items=0.000028s, per_item={'items': '0.00002766'}, temp_paths=1.864839) I0419 19:05:22.062705 140068444120896 future.py:372] [process=6][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 19:05:22.062742 140068444120896 future.py:372] [process=6][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 19:05:24.086060 139940704810752 array_metadata_store.py:203] [process=6][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/5/items/array_metadatas/process_6 I0419 19:06:01.212955 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/gbytes_per_sec: 40.298 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 39.197733879089355 s) (per-host) I0419 19:06:05.473501 140068444120896 event_tracking.py:125] [process=6] [sync] Finished blocking save in 48.60 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/5. I0419 19:06:10.674064 140068444120896 event_tracking.py:138] [process=6] [sync] Finished save in 53.80 seconds @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/5 I0419 19:06:10.675945 140068444120896 checkpoint_manager.py:2137] [process=6][thread=MainThread][step=5] CheckpointManager Save Finalize is syncing with other hosts... I0419 19:06:10.677640 140068444120896 checkpoint_manager.py:2146] [process=6][thread=MainThread][step=5] CheckpointManager Save Finalize is done on all hosts. I0419 19:06:10.677692 140068444120896 checkpoint_manager.py:1581] [process=6][thread=MainThread][step=5] Finished synchronous save. I0419 19:06:10.677745 140068444120896 standard_logger.py:34] {'step': 5, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776625516.8679252, 'wait_for_prev_duration_secs': 6.318092346191406e-05, 'time_between_consecutive_saves_sec': 1.7489511966705322, 'checkpointer_blocking_start_time': 1776625516.8696005, 'checkpointer_blocking_duration_secs': 53.80458092689514, 'get_old_steps_start_time': 1776625570.6742034, 'get_old_steps_duration_secs': 2.47955322265625e-05, 'checkpoint_manager_blocking_start_time': 1776625516.8655705, 'checkpoint_manager_blocking_duration_secs': 53.81214904785156} I0419 19:06:10.677829 140068444120896 checkpointing.py:410] Saved a checkpoint at step 5. I0419 19:06:10.678622 140068444120896 metric_logger.py:196] completed step: 4, seconds: 0.153, TFLOP/s/device: 88.720, Tokens/s/device: 13372.860, total_weights: 65536, loss: 9.460, lm_loss: 9.460, perplexity: 12840.355 I0419 19:06:10.700612 140068444120896 metric_logger.py:196] completed step: 5, seconds: 0.147, TFLOP/s/device: 92.416, Tokens/s/device: 13929.983, total_weights: 65536, loss: 8.959, lm_loss: 8.959, perplexity: 7776.467 I0419 19:06:33.809451 140068444120896 metric_logger.py:196] completed step: 6, seconds: 54.108, TFLOP/s/device: 0.251, Tokens/s/device: 37.850, total_weights: 65536, loss: 8.469, lm_loss: 8.469, perplexity: 4762.740 I0419 19:06:33.956907 140068444120896 metric_logger.py:196] completed step: 7, seconds: 22.979, TFLOP/s/device: 0.591, Tokens/s/device: 89.125, total_weights: 65536, loss: 8.003, lm_loss: 8.003, perplexity: 2989.151 I0419 19:06:34.104774 140068444120896 metric_logger.py:196] completed step: 8, seconds: 0.152, TFLOP/s/device: 89.275, Tokens/s/device: 13456.509, total_weights: 65536, loss: 7.572, lm_loss: 7.572, perplexity: 1943.098 I0419 19:06:34.251048 140068444120896 checkpointing.py:772] Waiting for step 9 to finish before checkpoint... I0419 19:06:34.251733 140068444120896 checkpointing.py:776] Waited 0.0007071495056152344 seconds for step 9 to finish before starting checkpointing. I0419 19:06:34.253817 140068444120896 checkpoint_manager.py:2009] [process=6][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 19:06:34.255747 140068444120896 checkpoint_manager.py:1512] [process=6] Saving checkpoint at step 9 I0419 19:06:34.257515 140068444120896 event_tracking.py:70] [process=6] [sync] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/9. I0419 19:06:38.174800 140068444120896 future.py:372] [process=6][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 19:06:39.537997 140068444120896 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0419 19:06:39.538094 140068444120896 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 19:06:39.582917 140068444120896 base_pytree_checkpoint_handler.py:154] [process=6][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.045947s I0419 19:06:39.583092 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/blocking_gbytes_per_sec: 30.887 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.049942731857299805 s) (per-host) I0419 19:06:39.583146 140068444120896 base_pytree_checkpoint_handler.py:768] [process=6][thread=MainThread] Initiated Pytree async_save. Time taken: 0.050007s (batch_requests_ready=0.001792s, total_serialization_initiated=0.048146s, others=0.000069s) I0419 19:06:39.583245 140068444120896 composite_checkpoint_handler.py:715] [process=6][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 1.409838s (all_items=0.000021s, per_item={'items': '0.00002050'}, temp_paths=1.409817) I0419 19:06:39.583285 140068444120896 future.py:372] [process=6][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 19:06:39.583323 140068444120896 future.py:372] [process=6][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 19:06:43.510652 139946601998080 array_metadata_store.py:203] [process=6][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/9/items/array_metadatas/process_6 I0419 19:07:18.895133 140068444120896 base_pytree_checkpoint_handler.py:130] [process=6] /jax/orbax/write/gbytes_per_sec: 40.130 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 39.3619441986084 s) (per-host) I0419 19:07:24.503546 140068444120896 event_tracking.py:125] [process=6] [sync] Finished blocking save in 50.25 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/9. I0419 19:07:28.713099 140068444120896 event_tracking.py:138] [process=6] [sync] Finished save in 54.46 seconds @ gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints/9 I0419 19:07:28.715365 140068444120896 checkpoint_manager.py:2137] [process=6][thread=MainThread][step=9] CheckpointManager Save Finalize is syncing with other hosts... I0419 19:07:28.717023 140068444120896 checkpoint_manager.py:2146] [process=6][thread=MainThread][step=9] CheckpointManager Save Finalize is done on all hosts. I0419 19:07:28.717073 140068444120896 checkpoint_manager.py:1581] [process=6][thread=MainThread][step=9] Finished synchronous save. I0419 19:07:28.717122 140068444120896 standard_logger.py:34] {'step': 9, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260419_180002/linen_xpk_main_20260419_180002_14_async_ckpt_false/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': True, 'wait_for_prev_start_time': 1776625594.2538, 'wait_for_prev_duration_secs': 5.841255187988281e-05, 'time_between_consecutive_saves_sec': 23.576119899749756, 'checkpointer_blocking_start_time': 1776625594.255831, 'checkpointer_blocking_duration_secs': 54.45738744735718, 'get_old_steps_start_time': 1776625648.7132323, 'get_old_steps_duration_secs': 2.0503997802734375e-05, 'checkpoint_manager_blocking_start_time': 1776625594.251957, 'checkpoint_manager_blocking_duration_secs': 54.465142011642456} I0419 19:07:28.717214 140068444120896 checkpointing.py:410] Saved a checkpoint at step 9. I0419 19:07:28.717262 140068444120896 checkpoint_manager.py:2009] [process=6][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 19:07:28.717306 140068444120896 checkpoint_manager.py:2009] [process=6][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0419 19:07:28.717997 140068444120896 metric_logger.py:196] completed step: 9, seconds: 0.147, TFLOP/s/device: 92.224, Tokens/s/device: 13900.956, total_weights: 65536, loss: 7.181, lm_loss: 7.181, perplexity: 1314.495 Per train step: Total TFLOPs: 13.59 split as 93.93% learnable weight flops and 6.07% attention flops XPK End: Sun Apr 19 19:07:37 UTC 2026 EXIT_CODE=0