XPK Start: Mon Apr 20 07:16:14 UTC 2026 PyTorch was not found. Models won't be available and only tokenizers, configuration and file/data utilities can be used. 2026-04-20 07:16:38.242202: 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) I0420 07:16:38.773853 137542338553664 max_utils.py:273] Attempting to initialize the jax distributed system... I0420 07:16:47.816251 137542338553664 distributed.py:149] Starting JAX distributed service on [::]:8482 I0420 07:16:47.818670 137542338553664 distributed.py:172] Connecting to JAX distributed service on mt-16-zarr3-true-sv-vluci-slice-job-0-0.mt-16-zarr3-true-sv-vluci:8482 I0420 07:16:48.926547 137542338553664 max_utils.py:284] Jax distributed system initialized! I0420 07:16:55.242302 137542338553664 max_utils.py:800] System Information: Jax Version: 0.9.2 I0420 07:16:55.242430 137542338553664 max_utils.py:801] System Information: Jaxlib Version: 0.9.2 I0420 07:16:55.242474 137542338553664 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 I0420 07:16:55.242511 137542338553664 train_utils.py:348] WARNING: Sequence packing is essentially ignored for synthetic data. Please use a real dataset to use sequence packing. I0420 07:16:55.942656 137542338553664 maxtext_utils.py:1551] Num_devices: 32, shape (1, 1, 1, 32, 1, 1, 1, 1, 1, 1, 1, 1, 1) I0420 07:16:55.942933 137542338553664 checkpointing.py:677] Setting up checkpoint logger... I0420 07:16:55.942986 137542338553664 checkpointing.py:233] Creating checkpoint manager with ocdbt=True and zarr3=True I0420 07:16:55.943032 137542338553664 pytree_checkpoint_handler.py:592] save_device_host_concurrent_bytes=None I0420 07:16:55.943374 137542338553664 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 0x7d178410a6c0>, enable_pinned_host_transfer=False, save_concurrent_bytes: 96000000000 (89.4 GiB), restore_concurrent_bytes: 96000000000 (89.4 GiB) I0420 07:16:58.806046 137542338553664 checkpointing.py:265] Enabling policy for fixed interval checkpointing. I0420 07:16:58.806276 137542338553664 checkpoint_manager.py:708] [process=4][thread=MainThread] CheckpointManager init: checkpointers=None, item_names=('items',), item_handlers={'items': <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7d02f0643050>}, handler_registry=None I0420 07:16:58.806525 137542338553664 composite_checkpoint_handler.py:237] Deferred registration for item: "items". Adding handler `<orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7d02f0643050>` 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`. I0420 07:16:58.806586 137542338553664 composite_checkpoint_handler.py:237] Deferred registration for item: "metrics". Adding handler `<orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7d02f0644050>` 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`. I0420 07:16:58.806628 137542338553664 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 0x7d02f0643050>, ('items', <class 'orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeRestoreArgs'>): <orbax.checkpoint._src.handlers.pytree_checkpoint_handler.PyTreeCheckpointHandler object at 0x7d02f0643050>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonSaveArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7d02f0644050>, ('metrics', <class 'orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonRestoreArgs'>): <orbax.checkpoint._src.handlers.json_checkpoint_handler.JsonCheckpointHandler object at 0x7d02f0644050>}). I0420 07:16:58.806951 137542338553664 abstract_checkpointer.py:35] orbax-checkpoint version: 0.11.34 I0420 07:16:58.807021 137542338553664 async_checkpointer.py:192] [process=4][thread=MainThread] Using barrier_sync_fn: <function get_barrier_sync_fn.<locals>._fn at 0x7d02f03db880> timeout: 1200 secs and primary_host=0 for async checkpoint writes I0420 07:16:59.976365 137542338553664 checkpoint_manager.py:1812] Found 0 checkpoint steps in gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints I0420 07:17:00.276830 137542338553664 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=True, 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_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints: <orbax.checkpoint.checkpoint_manager.CheckpointManager object at 0x7d02f079f8c0> I0420 07:17:00.276997 137542338553664 checkpointing.py:301] Checkpoint manager created! I0420 07:17:01.196409 137542338553664 nnx_wrappers.py:437] Unknown Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_norm_length', 'activation_embed'). I0420 07:17:01.196519 137542338553664 nnx_wrappers.py:437] Unknown Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0420 07:17:01.571112 137542338553664 attentions.py:1088] attentions/inputs_q Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0420 07:17:01.571200 137542338553664 attentions.py:1088] attentions/inputs_q Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0420 07:17:01.587372 137542338553664 attentions.py:1089] attentions/inputs_kv Logical: bfloat16[32,2048,2048]...................................... ('activation_batch', 'activation_attn_length', 'activation_attn_embed'). I0420 07:17:01.587427 137542338553664 attentions.py:1089] attentions/inputs_kv Physical: bfloat16[32,2048,2048]...................................... ('fsdp', None, None). I0420 07:17:01.611468 137542338553664 attentions.py:1154] attentions/query Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0420 07:17:01.611536 137542338553664 attentions.py:1154] attentions/query Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0420 07:17:01.627722 137542338553664 attentions.py:1155] attentions/key Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0420 07:17:01.627784 137542338553664 attentions.py:1155] attentions/key Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0420 07:17:01.644080 137542338553664 attentions.py:1156] attentions/value Logical: bfloat16[32,2048,16,128].................................... ('activation_kv_batch', 'activation_attn_length', 'activation_kv_heads', 'activation_kv_head_dim'). I0420 07:17:01.644138 137542338553664 attentions.py:1156] attentions/value Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0420 07:17:01.668555 137542338553664 attentions.py:1197] attentions/out Logical: bfloat16[32,2048,16,128].................................... ('activation_batch', 'activation_attn_length', 'activation_heads', 'activation_kv'). I0420 07:17:01.668625 137542338553664 attentions.py:1197] attentions/out Physical: bfloat16[32,2048,16,128].................................... ('fsdp', None, None, None). I0420 07:17:01.693949 137542338553664 linears.py:525] linears/x Logical: bfloat16[32,2048,7168]...................................... ('activation_batch', 'activation_length', 'activation_mlp'). I0420 07:17:01.694046 137542338553664 linears.py:525] linears/x Physical: bfloat16[32,2048,7168]...................................... ('fsdp', None, None). I0420 07:17:01.908438 137542338553664 checkpointing.py:577] checkpoint manager exists so trying to load this run's existing checkpoint I0420 07:17:01.908540 137542338553664 checkpointing.py:665] No existing checkpoints found, not restoring checkpoint. fsdp: 32 I0420 07:17:03.342322 137542338553664 maxtext_utils.py:1654] params/params/decoder/decoder_norm/scale Shape: float32[2048] Logical: P('norm',) Physical: (None,) I0420 07:17:03.342477 137542338553664 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) I0420 07:17:03.342529 137542338553664 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) I0420 07:17:03.342589 137542338553664 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') I0420 07:17:03.342643 137542338553664 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) I0420 07:17:03.342680 137542338553664 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) I0420 07:17:03.342733 137542338553664 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) I0420 07:17:03.342785 137542338553664 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') I0420 07:17:03.342824 137542338553664 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) I0420 07:17:03.342859 137542338553664 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) I0420 07:17:03.342905 137542338553664 maxtext_utils.py:1654] params/params/decoder/logits_dense/kernel Shape: float32[2048,32000] Logical: P('embed_vocab', 'vocab') Physical: ('fsdp', None) I0420 07:17:03.342952 137542338553664 maxtext_utils.py:1654] params/params/token_embedder/embedding Shape: float32[32000,2048] Logical: P('vocab', 'embed_vocab') Physical: (None, 'fsdp') I0420 07:17:03.833580 137542338553664 train.py:155] train/xent Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0420 07:17:03.833679 137542338553664 train.py:155] train/xent Physical: float32[32,2048]............................................ ('fsdp', None). I0420 07:17:03.848945 137542338553664 train.py:162] train/z_loss Logical: float32[32,2048]............................................ ('activation_embed_and_logits_batch', 'activation_length'). I0420 07:17:03.849003 137542338553664 train.py:162] train/z_loss Physical: float32[32,2048]............................................ ('fsdp', None). I0420 07:17:14.566355 137542338553664 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. I0420 07:17:14.567132 137542338553664 metric_logger.py:301] number parameters: 1.104 billion I0420 07:17:26.014483 137542338553664 checkpointing.py:772] Waiting for step 0 to finish before checkpoint... I0420 07:17:26.168104 137542338553664 checkpointing.py:776] Waited 0.15360283851623535 seconds for step 0 to finish before starting checkpointing. I0420 07:17:26.170780 137542338553664 checkpoint_manager.py:2009] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0420 07:17:26.172412 137542338553664 checkpoint_manager.py:1512] [process=4] Saving checkpoint at step 0 I0420 07:17:26.173855 137542338553664 event_tracking.py:70] [process=4] [async] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/0. I0420 07:17:26.504199 137542338553664 signaling_client.py:364] Using JaxDistributedSignalingClient I0420 07:17:26.505139 137542338553664 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0420 07:17:26.505197 137542338553664 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 I0420 07:17:26.777873 137542338553664 base_pytree_checkpoint_handler.py:154] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.273744s I0420 07:17:26.778046 137542338553664 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/blocking_gbytes_per_sec: 5.525 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.2792205810546875 s) (per-host) I0420 07:17:26.778098 137542338553664 base_pytree_checkpoint_handler.py:768] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.279282s (batch_requests_ready=0.002289s, total_serialization_initiated=0.276924s, others=0.000069s) I0420 07:17:26.778188 137542338553664 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 0.283413s (all_items=0.000018s, per_item={'items': '0.00001788'}, temp_paths=0.283395) I0420 07:17:26.779043 137542338553664 event_tracking.py:125] [process=4] [async] Finished blocking save in 0.61 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/0. I0420 07:17:26.779329 137412158699264 async_checkpointer.py:76] [process=4][thread=async_save] Background save thread started. Deadline for this save operation is 2026-04-20 07:37:26.779293 I0420 07:17:26.790814 137542338553664 checkpoint_manager.py:1560] [process=4][thread=MainThread][step=0] Starting CheckpointManager Save Finalize thread=save_finalize I0420 07:17:26.791093 137410552416000 async_checkpointer.py:280] [process=4][thread=save_finalize] Waiting for background save thread=async_save. I0420 07:17:26.791249 137542338553664 standard_logger.py:34] {'step': 0, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': False, 'wait_for_prev_start_time': 1776669446.1707616, 'wait_for_prev_duration_secs': 5.936622619628906e-05, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776669446.172449, 'checkpointer_blocking_duration_secs': 0.6070399284362793, 'get_old_steps_start_time': 1776669446.7795155, 'get_old_steps_duration_secs': 2.8371810913085938e-05, 'checkpoint_manager_blocking_start_time': 1776669446.1686616, 'checkpoint_manager_blocking_duration_secs': 0.6225507259368896} I0420 07:17:26.791373 137542338553664 checkpointing.py:408] Started an asynchronous checkpoint save for step 0 I0420 07:17:26.791424 137542338553664 max_utils.py:750] Memstats: After params initialized: I0420 07:17:26.791473 137542338553664 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_16(process=4,(0,4,0,0)) I0420 07:17:26.791506 137542338553664 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_17(process=4,(1,4,0,0)) I0420 07:17:26.791534 137542338553664 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_20(process=4,(0,5,0,0)) I0420 07:17:26.791559 137542338553664 max_utils.py:756] Using (GB) 0.43 / 31.25 (1.376000%) on TPU_21(process=4,(1,5,0,0)) I0420 07:17:27.106599 137542338553664 metric_logger.py:196] completed step: 0, seconds: 11.447, TFLOP/s/device: 1.187, Tokens/s/device: 178.908, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52779.875 I0420 07:17:27.278324 137542338553664 metric_logger.py:196] completed step: 1, seconds: 1.091, TFLOP/s/device: 12.458, Tokens/s/device: 1877.876, total_weights: 65536, loss: 10.874, lm_loss: 10.874, perplexity: 52779.875 I0420 07:17:27.688173 137542338553664 metric_logger.py:196] completed step: 2, seconds: 0.024, TFLOP/s/device: 558.245, Tokens/s/device: 84144.788, total_weights: 65536, loss: 10.560, lm_loss: 10.560, perplexity: 38547.719 I0420 07:17:27.835178 137542338553664 metric_logger.py:196] completed step: 3, seconds: 0.410, TFLOP/s/device: 33.173, Tokens/s/device: 5000.256, total_weights: 65536, loss: 9.980, lm_loss: 9.980, perplexity: 21590.506 I0420 07:17:27.839765 137542338553664 checkpointing.py:772] Waiting for step 5 to finish before checkpoint... I0420 07:17:28.129288 137542338553664 checkpointing.py:776] Waited 0.2894906997680664 seconds for step 5 to finish before starting checkpointing. I0420 07:17:28.132366 137542338553664 checkpoint_manager.py:2020] [process=4][thread=MainThread][step=0][wait_until_finished] Waiting for Save Finalize thread (save_finalize) to complete. I0420 07:17:29.739420 2865 google_auth_provider.cc:181] Running on GCE, using service account 562977990677-compute@developer.gserviceaccount.com I0420 07:17:32.252832 137410560808704 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/0/items/array_metadatas/process_4 I0420 07:18:03.264580 137412158699264 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/gbytes_per_sec: 42.964 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 36.765721559524536 s) (per-host) I0420 07:18:03.264697 137412158699264 async_checkpointer.py:90] [process=4][thread=async_save] 3 Handler Commit operations completed. Time taken: 36.485245s. I0420 07:18:12.005557 137412158699264 async_checkpointer.py:160] [process=4][thread=async_save] Background save thread done. Time taken: 45.226089s. I0420 07:18:12.005851 137410552416000 async_checkpointer.py:288] [process=4][thread=save_finalize] Done with waiting for background save thread=async_save. I0420 07:18:12.005975 137410552416000 async_checkpointer.py:298] [process=4][thread=save_finalize] No errors found in background save thread=async_save. I0420 07:18:12.006026 137410552416000 checkpoint_manager.py:2137] [process=4][thread=save_finalize][step=0] CheckpointManager Save Finalize is syncing with other hosts... I0420 07:18:12.008569 137410552416000 checkpoint_manager.py:2146] [process=4][thread=save_finalize][step=0] CheckpointManager Save Finalize is done on all hosts. I0420 07:18:12.008754 137542338553664 checkpoint_manager.py:2032] [process=4][thread=MainThread][step=0][wait_until_finished] Done waiting for Save Finalize thread (save_finalize) running at step=0. W0420 07:18:12.008895 137542338553664 checkpoint_manager.py:1452] Waiting for previous save to complete took 43.876545 seconds. If this number is high, consider checkpointing less frequently. I0420 07:18:12.010880 137542338553664 checkpoint_manager.py:1512] [process=4] Saving checkpoint at step 5 I0420 07:18:12.013251 137542338553664 event_tracking.py:70] [process=4] [async] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/5. I0420 07:18:12.741195 137542338553664 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0420 07:18:12.741293 137542338553664 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 I0420 07:18:12.774454 137542338553664 base_pytree_checkpoint_handler.py:154] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.034340s I0420 07:18:12.774657 137542338553664 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/blocking_gbytes_per_sec: 40.703 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.03789854049682617 s) (per-host) I0420 07:18:12.774709 137542338553664 base_pytree_checkpoint_handler.py:768] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.037960s (batch_requests_ready=0.001872s, total_serialization_initiated=0.036018s, others=0.000069s) I0420 07:18:12.774796 137542338553664 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 0.043129s (all_items=0.000016s, per_item={'items': '0.00001621'}, temp_paths=0.043113) I0420 07:18:12.775530 137542338553664 event_tracking.py:125] [process=4] [async] Finished blocking save in 0.76 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/5. I0420 07:18:12.775805 137410552416000 async_checkpointer.py:76] [process=4][thread=async_save] Background save thread started. Deadline for this save operation is 2026-04-20 07:38:12.775782 I0420 07:18:12.785679 137542338553664 checkpoint_manager.py:1560] [process=4][thread=MainThread][step=5] Starting CheckpointManager Save Finalize thread=save_finalize I0420 07:18:12.785980 137388747613952 async_checkpointer.py:280] [process=4][thread=save_finalize] Waiting for background save thread=async_save. I0420 07:18:12.786143 137542338553664 standard_logger.py:34] {'step': 5, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': False, 'wait_for_prev_start_time': 1776669448.1323204, 'wait_for_prev_duration_secs': 43.876544713974, 'time_between_consecutive_saves_sec': None, 'checkpointer_blocking_start_time': 1776669492.0109177, 'checkpointer_blocking_duration_secs': 0.7649953365325928, 'get_old_steps_start_time': 1776669492.7759364, 'get_old_steps_duration_secs': 2.9325485229492188e-05, 'checkpoint_manager_blocking_start_time': 1776669448.129948, 'checkpoint_manager_blocking_duration_secs': 44.65616154670715} I0420 07:18:12.786257 137542338553664 checkpointing.py:408] Started an asynchronous checkpoint save for step 5 I0420 07:18:12.787040 137542338553664 metric_logger.py:196] completed step: 4, seconds: 0.154, TFLOP/s/device: 88.438, Tokens/s/device: 13330.296, total_weights: 65536, loss: 9.460, lm_loss: 9.460, perplexity: 12840.355 I0420 07:18:12.792789 137542338553664 metric_logger.py:196] completed step: 5, seconds: 0.147, TFLOP/s/device: 92.421, Tokens/s/device: 13930.741, total_weights: 65536, loss: 8.959, lm_loss: 8.959, perplexity: 7776.467 I0420 07:18:17.971905 137410560808704 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/5/items/array_metadatas/process_4 I0420 07:18:35.226711 137542338553664 metric_logger.py:196] completed step: 6, seconds: 44.952, TFLOP/s/device: 0.302, Tokens/s/device: 45.560, total_weights: 65536, loss: 8.469, lm_loss: 8.469, perplexity: 4762.740 I0420 07:18:35.374139 137542338553664 metric_logger.py:196] completed step: 7, seconds: 22.288, TFLOP/s/device: 0.610, Tokens/s/device: 91.889, total_weights: 65536, loss: 8.003, lm_loss: 8.003, perplexity: 2989.151 I0420 07:18:35.521697 137542338553664 metric_logger.py:196] completed step: 8, seconds: 0.152, TFLOP/s/device: 89.411, Tokens/s/device: 13476.965, total_weights: 65536, loss: 7.572, lm_loss: 7.572, perplexity: 1943.098 I0420 07:18:35.668426 137542338553664 checkpointing.py:772] Waiting for step 9 to finish before checkpoint... I0420 07:18:35.669105 137542338553664 checkpointing.py:776] Waited 0.0006990432739257812 seconds for step 9 to finish before starting checkpointing. I0420 07:18:35.671230 137542338553664 checkpoint_manager.py:2020] [process=4][thread=MainThread][step=5][wait_until_finished] Waiting for Save Finalize thread (save_finalize) to complete. I0420 07:18:55.064854 137410552416000 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/gbytes_per_sec: 37.318 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 42.328054666519165 s) (per-host) I0420 07:18:55.064978 137410552416000 async_checkpointer.py:90] [process=4][thread=async_save] 3 Handler Commit operations completed. Time taken: 42.289090s. I0420 07:19:02.974133 137410552416000 async_checkpointer.py:160] [process=4][thread=async_save] Background save thread done. Time taken: 50.198228s. I0420 07:19:02.974433 137388747613952 async_checkpointer.py:288] [process=4][thread=save_finalize] Done with waiting for background save thread=async_save. I0420 07:19:02.974554 137388747613952 async_checkpointer.py:298] [process=4][thread=save_finalize] No errors found in background save thread=async_save. I0420 07:19:02.974602 137388747613952 checkpoint_manager.py:2137] [process=4][thread=save_finalize][step=5] CheckpointManager Save Finalize is syncing with other hosts... I0420 07:19:02.976805 137388747613952 checkpoint_manager.py:2146] [process=4][thread=save_finalize][step=5] CheckpointManager Save Finalize is done on all hosts. I0420 07:19:02.976962 137542338553664 checkpoint_manager.py:2032] [process=4][thread=MainThread][step=5][wait_until_finished] Done waiting for Save Finalize thread (save_finalize) running at step=5. W0420 07:19:02.977081 137542338553664 checkpoint_manager.py:1452] Waiting for previous save to complete took 27.305858 seconds. If this number is high, consider checkpointing less frequently. I0420 07:19:02.981086 137542338553664 checkpoint_manager.py:1512] [process=4] Saving checkpoint at step 9 I0420 07:19:02.983196 137542338553664 event_tracking.py:70] [process=4] [async] Started save checkpoint @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/9. I0420 07:19:03.294789 137542338553664 jax_array_handlers.py:360] Scheduling D2H of 39 prioritized jax.Array. I0420 07:19:03.294882 137542338553664 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 I0420 07:19:03.327592 137542338553664 base_pytree_checkpoint_handler.py:154] [process=4][thread=MainThread] Initiated "orbax.checkpoint._src.serialization.jax_array_handlers.ArrayHandler".serialize. Time taken: 0.033633s I0420 07:19:03.327753 137542338553664 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/blocking_gbytes_per_sec: 41.559 GiB/s (total gbytes: 1.5 GiB) (time elapsed: 0.037117958068847656 s) (per-host) I0420 07:19:03.327803 137542338553664 base_pytree_checkpoint_handler.py:768] [process=4][thread=MainThread] Initiated Pytree async_save. Time taken: 0.037177s (batch_requests_ready=0.001746s, total_serialization_initiated=0.035367s, others=0.000064s) I0420 07:19:03.327901 137542338553664 composite_checkpoint_handler.py:715] [process=4][thread=MainThread] Initiated CompositeCheckpointHandler.async_save. Time taken: 0.041232s (all_items=0.000010s, per_item={'items': '0.00001025'}, temp_paths=0.041222) I0420 07:19:03.328608 137542338553664 event_tracking.py:125] [process=4] [async] Finished blocking save in 0.35 seconds. Continuing save @ gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/9. I0420 07:19:03.328880 137388747613952 async_checkpointer.py:76] [process=4][thread=async_save] Background save thread started. Deadline for this save operation is 2026-04-20 07:39:03.328858 I0420 07:19:03.338919 137542338553664 checkpoint_manager.py:1560] [process=4][thread=MainThread][step=9] Starting CheckpointManager Save Finalize thread=save_finalize I0420 07:19:03.339206 137410560808704 async_checkpointer.py:280] [process=4][thread=save_finalize] Waiting for background save thread=async_save. I0420 07:19:03.339380 137542338553664 standard_logger.py:34] {'step': 9, 'event_type': 'save', 'directory': 'gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints', 'reached_preemption': False, 'preemption_received_at': None, 'synchronous': False, 'wait_for_prev_start_time': 1776669515.6711993, 'wait_for_prev_duration_secs': 27.30585789680481, 'time_between_consecutive_saves_sec': 23.662587881088257, 'checkpointer_blocking_start_time': 1776669542.981126, 'checkpointer_blocking_duration_secs': 0.34784626960754395, 'get_old_steps_start_time': 1776669543.3289897, 'get_old_steps_duration_secs': 2.5987625122070312e-05, 'checkpoint_manager_blocking_start_time': 1776669515.6693308, 'checkpoint_manager_blocking_duration_secs': 27.670016527175903} I0420 07:19:03.339495 137542338553664 checkpointing.py:408] Started an asynchronous checkpoint save for step 9 I0420 07:19:03.339537 137542338553664 checkpoint_manager.py:2020] [process=4][thread=MainThread][step=9][wait_until_finished] Waiting for Save Finalize thread (save_finalize) to complete. I0420 07:19:08.417920 137409990600448 array_metadata_store.py:203] [process=4][thread=array_type_handler] Wrote 39 array_metadata.ArrayMetadata to gs://lance-maxtext/linen_ckpt_xpk_main_20260420_060028/linen_xpk_main_20260420_060028_16_zarr3_true/checkpoints/9/items/array_metadatas/process_4 I0420 07:19:45.205867 137388747613952 base_pytree_checkpoint_handler.py:130] [process=4] /jax/orbax/write/gbytes_per_sec: 37.686 MiB/s (total gbytes: 1.5 GiB) (time elapsed: 41.91518783569336 s) (per-host) I0420 07:19:45.205987 137388747613952 async_checkpointer.py:90] [process=4][thread=async_save] 3 Handler Commit operations completed. Time taken: 41.877038s. I0420 07:19:52.698626 137388747613952 async_checkpointer.py:160] [process=4][thread=async_save] Background save thread done. Time taken: 49.369661s. I0420 07:19:52.698922 137410560808704 async_checkpointer.py:288] [process=4][thread=save_finalize] Done with waiting for background save thread=async_save. I0420 07:19:52.699042 137410560808704 async_checkpointer.py:298] [process=4][thread=save_finalize] No errors found in background save thread=async_save. I0420 07:19:52.699084 137410560808704 checkpoint_manager.py:2137] [process=4][thread=save_finalize][step=9] CheckpointManager Save Finalize is syncing with other hosts... I0420 07:19:52.704137 137410560808704 checkpoint_manager.py:2146] [process=4][thread=save_finalize][step=9] CheckpointManager Save Finalize is done on all hosts. I0420 07:19:52.704298 137542338553664 checkpoint_manager.py:2032] [process=4][thread=MainThread][step=9][wait_until_finished] Done waiting for Save Finalize thread (save_finalize) running at step=9. I0420 07:19:52.704495 137542338553664 checkpoint_manager.py:2009] [process=4][thread=MainThread][wait_until_finished] No Save Finalize thread to wait for. Returning. I0420 07:19:52.705415 137542338553664 metric_logger.py:196] completed step: 9, seconds: 0.148, TFLOP/s/device: 92.054, Tokens/s/device: 13875.339, 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: Mon Apr 20 07:20:05 UTC 2026 EXIT_CODE=0