use train_loss for sp test

* synthetic datasets for benchmarking and testing

* fix synthetic dataset parse from config and add tests

* use type=_synthetic

_quarto.yml

@@ -128,11 +128,9 @@ quartodoc:
         - monkeypatch.mistral_attn_hijack_flash
         - monkeypatch.multipack
         - monkeypatch.relora
-        - monkeypatch.llama_expand_mask
         - monkeypatch.lora_kernels
         - monkeypatch.utils
         - monkeypatch.btlm_attn_hijack_flash
-        - monkeypatch.llama_patch_multipack
         - monkeypatch.stablelm_attn_hijack_flash
         - monkeypatch.trainer_fsdp_optim
         - monkeypatch.transformers_fa_utils

cicd/cicd.sh

@@ -3,7 +3,8 @@ set -e
 
 python -c "import torch; assert '$PYTORCH_VERSION' in torch.__version__"
 
-curl -L https://axolotl-ci.b-cdn.net/hf-cache.tar.zst | tar -xpf - -C "${HF_HOME}/hub/"  --use-compress-program unzstd --strip-components=1
+set -o pipefail
+curl --silent --show-error --fail --retry 3 --retry-delay 5 -L https://axolotl-ci.b-cdn.net/hf-cache.tar.zst | tar -xpf - -C "${HF_HOME}/hub/" --use-compress-program unzstd --strip-components=1
 # hf download "NousResearch/Meta-Llama-3-8B"
 # hf download "NousResearch/Meta-Llama-3-8B-Instruct"
 # hf download "microsoft/Phi-4-reasoning"

codecov.yml

@@ -37,6 +37,7 @@ coverage:
         only_pulls: false
         flags: null
         paths: null
+        informational: true
 
 parsers:
   gcov:

docs/gradient_checkpointing.qmd

@@ -1,5 +1,5 @@
 ---
-title: Gradient Checkpointing and Activation Offloading
+title: Gradient Checkpointing, Activation Offloading, and Layer Offloading
 ---
 
 Gradient checkpointing and activation offloading are techniques used to optimize the performance of deep learning
@@ -27,3 +27,33 @@ The `activation_offloading: legacy` naively offloads activations to CPU and with
 
 For resource constrained environments with limited CPU memory, `activation_offloading: disk` offloads
 activations to disk instead of CPU RAM so that much larger context lengths can be trained with minimal memory.
+
+### Enabling Layer Offloading
+
+```yaml
+layer_offloading: true
+```
+
+Layer offloading reduces GPU memory usage by moving frozen (non-trainable) decoder layer parameters to CPU
+and streaming them back to GPU one layer at a time during the forward and backward passes. This is
+particularly useful for LoRA/QLoRA training where most of the model's parameters are frozen — only the
+trainable adapter weights stay on GPU permanently.
+
+During training, forward and backward hooks on each decoder layer handle the transfer automatically:
+
+- **Forward pass:** Before a layer executes, its frozen params are loaded to GPU. The next layer is
+  prefetched asynchronously on a separate CUDA stream for overlap.
+- **Backward pass:** Same pattern in reverse — the current layer's frozen params are loaded and the
+  previous layer is prefetched.
+
+After each layer finishes, its frozen params are offloaded back to CPU pinned memory.
+
+This approach trades some CPU-GPU transfer overhead for significant GPU memory savings — the freed memory
+is roughly equal to the size of all frozen parameters across all decoder layers, minus one layer's worth
+that is kept on GPU at any given time.
+
+**Requirements:**
+
+- CUDA GPU (CPU-only training is not supported for this feature)
+- Works with any HuggingFace model architecture that uses decoder layers (Llama, Mistral, Qwen, etc.)
+- Best combined with LoRA/QLoRA where most parameters are frozen

docs/optimizations.qmd

@@ -54,6 +54,13 @@ These techniques save VRAM by changing how activations are handled.
 - Activation Offloading: moves activations to CPU RAM or disk, trading I/O overhead for VRAM.
 - Learn more: [Gradient Checkpointing and Offloading Docs](gradient_checkpointing.qmd)
 
+### Layer Offloading
+
+Offloads frozen (non-trainable) decoder layer parameters to CPU and streams them back to GPU one layer at a time during forward/backward passes using CUDA stream prefetching. Especially effective for LoRA/QLoRA where most parameters are frozen.
+
+- **Config:** `layer_offloading: true`
+- **Learn more:** [Layer Offloading Docs](gradient_checkpointing.qmd#enabling-layer-offloading)
+
 ### Cut Cross Entropy (CCE)
 
 Reduces VRAM usage by using an optimized cross-entropy loss calculation.

examples/mistral4/README.md

@@ -6,9 +6,6 @@ Thanks to the team at MistralAI for giving us early access to prepare for this r
 
 ## Getting started
 
-Note: Training this model requires weights in BF16 which we will link to later.
-Users interested in training can convert / descale the existing FP8 weights.
-
 1. Install Axolotl following the [installation guide](https://docs.axolotl.ai/docs/installation.html).
 
 2. Install [Cut Cross Entropy](https://docs.axolotl.ai/docs/custom_integrations.html#cut-cross-entropy) to reduce training VRAM usage

examples/mistral4/fft-text.yml

@@ -1,4 +1,4 @@
-base_model: mistralai/Mistral-Small-4-119B-2603
+base_model: axolotl-ai-co/Mistral-Small-4-119B-2603-BF16
 
 plugins:
   - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin

examples/mistral4/fft-vision.yml

@@ -1,4 +1,4 @@
-base_model: mistralai/Mistral-Small-4-119B-2603
+base_model: axolotl-ai-co/Mistral-Small-4-119B-2603-BF16
 processor_type: AutoProcessor
 
 plugins:

examples/mistral4/qlora-text.yml

@@ -1,4 +1,4 @@
-base_model: mistralai/Mistral-Small-4-119B-2603
+base_model: axolotl-ai-co/Mistral-Small-4-119B-2603-BF16
 
 plugins:
   - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin

examples/mistral4/qlora-vision.yml

@@ -1,4 +1,4 @@
-base_model: mistralai/Mistral-Small-4-119B-2603
+base_model: axolotl-ai-co/Mistral-Small-4-119B-2603-BF16
 processor_type: AutoProcessor
 
 plugins:

examples/qwen3.5/122b-a10b-moe-qlora-fsdp.yaml

@@ -0,0 +1,84 @@
+base_model: Qwen/Qwen3.5-122B-A10B
+
+plugins:
+  - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin
+strict: false
+
+chat_template: qwen3_5
+datasets:
+  - path: mlabonne/FineTome-100k
+    type: chat_template
+    split: train[:20%]
+    field_messages: conversations
+    message_property_mappings:
+      role: from
+      content: value
+val_set_size: 0.0
+output_dir: ./outputs/out
+dataset_prepared_path: last_run_prepared
+
+sequence_len: 2048
+sample_packing: true
+
+load_in_4bit: true
+quantize_moe_experts: true
+adapter: qlora
+lora_r: 16
+lora_alpha: 32
+lora_dropout: 0
+lora_target_modules:
+  - q_proj
+  - k_proj
+  - v_proj
+  - o_proj
+# Regex matching to target shared experts too
+# lora_target_modules: 'model\.(language_model\.)?layers\.[\d]+\.(mlp|self_attn)\.(shared_expert\.)?(up|down|gate|gate_up|q|k|v|o)_proj'
+
+# Target experts
+# lora_target_parameters:
+#   - mlp.experts.gate_up_proj
+#   - mlp.experts.down_proj
+
+wandb_project:
+wandb_entity:
+wandb_watch:
+wandb_name:
+wandb_log_model:
+
+gradient_accumulation_steps: 2
+micro_batch_size: 1
+num_epochs: 1
+optimizer: adamw_torch_4bit
+lr_scheduler: cosine
+learning_rate: 0.0002
+
+bf16: auto
+tf32: true
+
+lora_mlp_kernel: false
+lora_qkv_kernel: false
+lora_o_kernel: false
+
+gradient_checkpointing: true
+gradient_checkpointing_kwargs:
+  use_reentrant: false
+resume_from_checkpoint:
+logging_steps: 1
+flash_attention: true
+
+warmup_ratio: 0.1
+evals_per_epoch: 4
+saves_per_epoch: 1
+weight_decay: 0.0
+special_tokens:
+
+fsdp_config:
+  fsdp_version: 2
+  offload_params: true
+  cpu_ram_efficient_loading: false
+  auto_wrap_policy: TRANSFORMER_BASED_WRAP
+  transformer_layer_cls_to_wrap: Qwen3_5MoeDecoderLayer
+  state_dict_type: FULL_STATE_DICT
+  sharding_strategy: FULL_SHARD
+  reshard_after_forward: true
+  activation_checkpointing: true

examples/qwen3.5/122b-a10b-moe-qlora.yaml

@@ -32,7 +32,11 @@ lora_target_modules:
   - v_proj
   - o_proj
 
-#lora_target_parameters:
+# Regex matching to target shared experts too
+# lora_target_modules: 'model\.(language_model\.)?layers\.[\d]+\.(mlp|self_attn)\.(shared_expert\.)?(up|down|gate|gate_up|q|k|v|o)_proj'
+
+# Target experts
+# lora_target_parameters:
 #   - mlp.experts.gate_up_proj
 #   - mlp.experts.down_proj
 
@@ -52,7 +56,6 @@ learning_rate: 0.0002
 bf16: auto
 tf32: true
 
-
 lora_mlp_kernel: false
 lora_qkv_kernel: false
 lora_o_kernel: false

examples/qwen3.5/27b-qlora-fsdp.yaml

@@ -0,0 +1,81 @@
+base_model: Qwen/Qwen3.5-27B
+
+# Automatically upload checkpoint and final model to HF
+# hub_model_id: username/custom_model_name
+
+plugins:
+  - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin
+strict: false
+
+chat_template: qwen3_5
+datasets:
+  - path: mlabonne/FineTome-100k
+    type: chat_template
+    split: train[:20%]
+    field_messages: conversations
+    message_property_mappings:
+      role: from
+      content: value
+val_set_size: 0.0
+output_dir: ./outputs/out
+dataset_prepared_path: last_run_prepared
+
+sequence_len: 2048
+sample_packing: true
+
+load_in_4bit: true
+adapter: qlora
+lora_r: 16
+lora_alpha: 32
+lora_target_modules:
+  - q_proj
+  - k_proj
+  - v_proj
+  - o_proj
+  - down_proj
+  - up_proj
+  # Uncomment below to also target the linear attention projections.
+  # These use separate in_proj_qkv / in_proj_z / out_proj (Qwen3.5-specific).
+  # - linear_attn.in_proj_qkv
+  # - linear_attn.in_proj_z
+  # - linear_attn.out_proj
+
+wandb_project:
+wandb_entity:
+wandb_watch:
+wandb_name:
+wandb_log_model:
+
+gradient_accumulation_steps: 2
+micro_batch_size: 1
+num_epochs: 1
+optimizer: adamw_torch_4bit
+lr_scheduler: cosine
+learning_rate: 0.0002
+
+bf16: auto
+tf32: true
+
+gradient_checkpointing: true
+gradient_checkpointing_kwargs:
+  use_reentrant: false
+resume_from_checkpoint:
+logging_steps: 1
+flash_attention: true
+
+warmup_ratio: 0.1
+evals_per_epoch: 4
+saves_per_epoch: 1
+weight_decay: 0.0
+special_tokens:
+
+fsdp_config:
+  fsdp_version: 2
+  offload_params: false
+  cpu_ram_efficient_loading: false
+  auto_wrap_policy: TRANSFORMER_BASED_WRAP
+  transformer_layer_cls_to_wrap: Qwen3_5DecoderLayer
+  state_dict_type: FULL_STATE_DICT
+  sharding_strategy: FULL_SHARD
+  reshard_after_forward: true
+  activation_checkpointing: true

examples/qwen3.5/27b-qlora.yaml

@@ -1,9 +1,7 @@
 base_model: Qwen/Qwen3.5-27B
+
 # Automatically upload checkpoint and final model to HF
 # hub_model_id: username/custom_model_name
-# Note: Qwen3.5 is an early-fusion VLM (image+text). This config fine-tunes
-# the text-only path. For multimodal (image+text) fine-tuning, add image
-# columns to your dataset following axolotl's multimodal dataset format.
 
 plugins:
   - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin

examples/qwen3.5/35b-a3b-moe-qlora-fsdp.yaml

@@ -0,0 +1,85 @@
+base_model: Qwen/Qwen3.5-35B-A3B
+
+plugins:
+  - axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin
+strict: false
+
+chat_template: qwen3_5
+datasets:
+  - path: mlabonne/FineTome-100k
+    type: chat_template
+    split: train[:20%]
+    field_messages: conversations
+    message_property_mappings:
+      role: from
+      content: value
+val_set_size: 0.0
+output_dir: ./outputs/out
+dataset_prepared_path: last_run_prepared
+
+sequence_len: 2048
+sample_packing: true
+
+load_in_4bit: true
+quantize_moe_experts: true
+adapter: qlora
+lora_r: 16
+lora_alpha: 32
+lora_dropout: 0
+lora_target_modules:
+  - q_proj
+  - k_proj
+  - v_proj
+  - o_proj
+
+# Regex matching to target shared experts too
+# lora_target_modules: 'model\.(language_model\.)?layers\.[\d]+\.(mlp|self_attn)\.(shared_expert\.)?(up|down|gate|gate_up|q|k|v|o)_proj'
+
+# Target experts
+# lora_target_parameters:
+#   - mlp.experts.gate_up_proj
+#   - mlp.experts.down_proj
+
+wandb_project:
+wandb_entity:
+wandb_watch:
+wandb_name:
+wandb_log_model:
+
+gradient_accumulation_steps: 2
+micro_batch_size: 1
+num_epochs: 1
+optimizer: adamw_torch_4bit
+lr_scheduler: cosine
+learning_rate: 0.0002
+
+bf16: auto
+tf32: true
+
+lora_mlp_kernel: false
+lora_qkv_kernel: false
+lora_o_kernel: false
+
+gradient_checkpointing: true
+gradient_checkpointing_kwargs:
+  use_reentrant: false
+resume_from_checkpoint:
+logging_steps: 1
+flash_attention: true
+
+warmup_ratio: 0.1
+evals_per_epoch: 4
+saves_per_epoch: 1
+weight_decay: 0.0
+special_tokens:
+
+fsdp_config:
+  fsdp_version: 2
+  offload_params: true
+  cpu_ram_efficient_loading: false
+  auto_wrap_policy: TRANSFORMER_BASED_WRAP
+  transformer_layer_cls_to_wrap: Qwen3_5MoeDecoderLayer
+  state_dict_type: FULL_STATE_DICT
+  sharding_strategy: FULL_SHARD
+  reshard_after_forward: true
+  activation_checkpointing: true

examples/qwen3.5/35b-a3b-moe-qlora.yaml

@@ -32,7 +32,11 @@ lora_target_modules:
   - v_proj
   - o_proj
 
-#lora_target_parameters:
+# Regex matching to target shared experts too
+# lora_target_modules: 'model\.(language_model\.)?layers\.[\d]+\.(mlp|self_attn)\.(shared_expert\.)?(up|down|gate|gate_up|q|k|v|o)_proj'
+
+# Target experts
+# lora_target_parameters:
 #   - mlp.experts.gate_up_proj
 #   - mlp.experts.down_proj
 

examples/qwen3.5/9b-lora-vision.yaml

@@ -26,8 +26,6 @@ lora_r: 32
 lora_alpha: 16
 lora_dropout: 0.05
 # Targets the language model attention and MLP layers.
-# Qwen3.5 is early-fusion: all layers (including those seeing vision tokens) share
-# the same transformer stack, so standard attention targets work for both modalities.
 lora_target_modules:
   - q_proj
   - k_proj

examples/qwen3.5/README.md

@@ -2,20 +2,6 @@
 
 [Qwen3.5](https://huggingface.co/collections/Qwen/qwen35) is a hybrid architecture model series combining Gated DeltaNet linear attention with standard Transformer attention. All Qwen3.5 models are early-fusion vision-language models: dense variants use `Qwen3_5ForConditionalGeneration` and MoE variants use `Qwen3_5MoeForConditionalGeneration`.
 
-Vision and text tokens are processed through the same transformer stack. The configs below train on text-only data unless noted otherwise. See `9b-lora-vision.yaml` for a multimodal example.
-
-Available configs:
-
-| Config | Model | Type | Peak VRAM |
-|---|---|---|---|
-| `27b-qlora.yaml` | Qwen3.5-27B | Dense VLM, text-only QLoRA | ~47 GiB |
-| `27b-fft.yaml` | Qwen3.5-27B | Dense VLM, text-only FFT (vision frozen) | ~53 GiB |
-| `35b-a3b-moe-qlora.yaml` | Qwen3.5-35B-A3B | MoE, text-only QLoRA | — |
-| `122b-a10b-moe-qlora.yaml` | Qwen3.5-122B-A10B | MoE, text-only QLoRA | — |
-| `9b-lora-vision.yaml` | Qwen3.5-9B | Vision+text LoRA, single GPU | — |
-| `9b-fft-vision.yaml` | Qwen3.5-9B | Vision+text FFT, single GPU | ~61 GiB |
-
-
 ## Getting started
 
 1. Install Axolotl following the [installation guide](https://docs.axolotl.ai/docs/installation.html).
@@ -23,43 +9,69 @@ Available configs:
 2. Install [Cut Cross Entropy](https://docs.axolotl.ai/docs/custom_integrations.html#cut-cross-entropy) to reduce training VRAM usage.
 
 3. Install FLA for sample packing support with the Gated DeltaNet linear attention layers:
-```bash
-pip3 uninstall -y causal-conv1d && pip3 install flash-linear-attention==0.4.1
+  ```bash
+  pip3 uninstall -y causal-conv1d && pip3 install flash-linear-attention==0.4.1
+  ```
+  > FLA is required when `sample_packing: true`. Without it, training raises a `RuntimeError` on packed sequences. Vision configs use `sample_packing: false` so FLA is optional there.
+
+4. Pick any config from the table below and run:
+
+    ```bash
+    axolotl train examples/qwen3.5/<config>.yaml
+    ```
+
+Available configs:
+
+| Config | Model | Type | Peak VRAM |
+|---|---|---|---|
+| `9b-lora-vision.yaml` | Qwen3.5-9B | Vision+text LoRA, single GPU | — |
+| `9b-fft-vision.yaml` | Qwen3.5-9B | Vision+text FFT, single GPU | ~61 GiB |
+| `27b-qlora.yaml` | Qwen3.5-27B | Dense, text-only QLoRA | ~47 GiB |
+| `27b-fft.yaml` | Qwen3.5-27B | Dense, text-only FFT (vision frozen) | ~53 GiB |
+| `27b-qlora-fsdp.yaml` | Qwen3.5-27B | Dense, text-only QLoRA + FSDP2 | — |
+| `35b-a3b-moe-qlora.yaml` | Qwen3.5-35B-A3B | MoE, text-only QLoRA | — |
+| `35b-a3b-moe-qlora-fsdp.yaml` | Qwen3.5-35B-A3B | MoE, text-only QLoRA + FSDP2 | — |
+| `122b-a10b-moe-qlora.yaml` | Qwen3.5-122B-A10B | MoE, text-only QLoRA | — |
+| `122b-a10b-moe-qlora-fsdp.yaml` | Qwen3.5-122B-A10B | MoE, text-only QLoRA + FSDP2 | — |
+
+### Gated DeltaNet Linear Attention
+
+Qwen3.5 interleaves standard attention with Gated DeltaNet linear attention layers. To apply LoRA to them, add to `lora_target_modules`:
+
+```yaml
+lora_target_modules:
+  # ... standard projections ...
+  - linear_attn.in_proj_qkv
+  - linear_attn.in_proj_z
+  - linear_attn.out_proj
 ```
-> FLA is required when `sample_packing: true`. Without it, training raises a `RuntimeError` on packed sequences. Vision configs use `sample_packing: false` so FLA is optional there.
 
-4. Run a finetuning example:
+### Routed Experts (MoE)
 
-```bash
-# Dense 27B text-only (QLoRA, ~47 GiB VRAM with sample packing)
-axolotl train examples/qwen3.5/27b-qlora.yaml
+To apply LoRA to routed expert parameters, add `lora_target_parameters`:
 
-# Dense 27B text-only FFT with vision encoder frozen (~53 GiB, single 80 GiB GPU)
-axolotl train examples/qwen3.5/27b-fft.yaml
+```yaml
+lora_target_parameters:
+  - mlp.experts.gate_up_proj
+  - mlp.experts.down_proj
+#  - mlp.gate.weight  # router
+```
 
-# MoE 35B-A3B text-only (QLoRA)
-axolotl train examples/qwen3.5/35b-a3b-moe-qlora.yaml
+### Shared Experts (MoE)
 
-# MoE 122B-A10B text-only (QLoRA)
-axolotl train examples/qwen3.5/122b-a10b-moe-qlora.yaml
-
-# 9B vision+text (LoRA, multimodal dataset)
-axolotl train examples/qwen3.5/9b-lora-vision.yaml
-
-# 9B vision+text FFT, single 80 GiB GPU (~61 GiB peak)
-axolotl train examples/qwen3.5/9b-fft-vision.yaml
+Routed experts and shared experts both have `gate_up_proj`/`down_proj`, so a plain module name in `lora_target_modules` would match both. Use a regex to target only attention and shared expert projections, while `lora_target_parameters` above handles routed experts separately:
 
+```yaml
+lora_target_modules: 'model\.(language_model\.)?layers\.[\d]+\.(mlp|self_attn)\.(shared_expert\.)?(up|down|gate|gate_up|q|k|v|o)_proj'
 ```
 
 ### TIPS
 
-- For inference, you can experiment with `temperature: 0.7`, `top_p: 0.8`, `top_k: 20`, and `min_p: 0`.
-- For **text-only FFT** on 27B, use `27b-fft.yaml` which sets `unfrozen_parameters` to freeze the vision encoder (`model.visual.*`) — this avoids wasting optimizer state on parameters that receive no gradient from text-only data.
+- For inference hyp, please see the respective model card details.
 - You can run a full finetuning of smaller configs by removing `adapter: qlora` and `load_in_4bit: true`. See [Multi-GPU](#optimization-guides) below.
 - Read more on loading your own dataset at [docs](https://docs.axolotl.ai/docs/dataset_loading.html).
 - The dataset format follows the OpenAI Messages format as seen [here](https://docs.axolotl.ai/docs/dataset-formats/conversation.html#chat_template).
 - For **multimodal** finetuning, set `processor_type: AutoProcessor`, `skip_prepare_dataset: true`, and `remove_unused_columns: false` as shown in `9b-lora-vision.yaml`.
-- The Gated DeltaNet linear attention layers (`linear_attn.*`) can optionally be added to `lora_target_modules` — they are commented out by default.
 
 ## Optimization Guides
 

pyproject.toml

@@ -61,5 +61,11 @@ skip-magic-trailing-comma = false
 line-ending = "auto"
 docstring-code-format = false
 
+[tool.pytest.ini_options]
+addopts = "-m 'not slow'"
+markers = [
+    "slow: marks tests as slow",
+]
+
 [tool.uv.extra-build-dependencies]
 axolotl = ["huggingface_hub"]

setup.py

@@ -81,16 +81,23 @@ def parse_requirements(extras_require_map):
                     f"https://download.pytorch.org/whl/{torch_cuda_version}"
                 )
 
-            if (major, minor) >= (2, 9):
+            if (major, minor) >= (2, 10):
+                extras_require_map.pop("fbgemm-gpu")
+                extras_require_map["fbgemm-gpu"] = [
+                    "fbgemm-gpu==1.5.0",
+                    "fbgemm-gpu-genai==1.5.0",
+                ]
+                if not install_xformers:
+                    _install_requires.pop(_install_requires.index(xformers_version))
+                extras_require_map["vllm"] = ["vllm==0.17.1"]
+            elif (major, minor) >= (2, 9):
                 extras_require_map.pop("fbgemm-gpu")
                 extras_require_map["fbgemm-gpu"] = [
                     "fbgemm-gpu==1.4.0",
                     "fbgemm-gpu-genai==1.4.2",
                 ]
-                extras_require_map["vllm"] = ["vllm==0.11.1"]
                 if not install_xformers:
                     _install_requires.pop(_install_requires.index(xformers_version))
-                extras_require_map["vllm"] = ["vllm==0.13.0"]
                 if patch == 0:
                     extras_require_map["vllm"] = ["vllm==0.13.0"]
                 else:

src/axolotl/cli/checks.py

@@ -3,6 +3,7 @@
 import os
 from pathlib import Path
 
+import httpcore
 from accelerate.commands.config import config_args
 from huggingface_hub import HfApi
 from huggingface_hub.utils import LocalTokenNotFoundError
@@ -47,7 +48,7 @@ def check_user_token() -> bool:
             "Error verifying HuggingFace token. Remember to log in using `hf auth login` and get your access token from https://huggingface.co/settings/tokens if you want to use gated models or datasets."
         )
         return False
-    except HTTPError:
+    except (HTTPError, httpcore.ConnectError):
         LOG.warning(
             "Error accessing HuggingFace. This may be due to a network issue or rate limiting."
         )

src/axolotl/core/builders/base.py

@@ -353,6 +353,30 @@ class TrainerBuilderBase(abc.ABC):
                 adam_kwargs["eps"] = (eps1, eps2)
 
                 optimizer_kwargs.update(adam_kwargs)
+            elif self.cfg.optimizer == "flash_adamw":
+                from flashoptim import FlashAdamW
+
+                optimizer_cls = FlashAdamW
+                optimizer_kwargs.update(adam_kwargs)
+            elif self.cfg.optimizer == "flash_adam":
+                from flashoptim import FlashAdam
+
+                optimizer_cls = FlashAdam
+                optimizer_kwargs.update(adam_kwargs)
+            elif self.cfg.optimizer == "flash_sgd":
+                from flashoptim import FlashSGD
+
+                optimizer_cls = FlashSGD
+            elif self.cfg.optimizer == "flash_sgdw":
+                from flashoptim import FlashSGDW
+
+                optimizer_cls = FlashSGDW
+            elif self.cfg.optimizer == "flash_lion":
+                from flashoptim import FlashLion
+
+                optimizer_cls = FlashLion
+                if "betas" in adam_kwargs:
+                    optimizer_kwargs["betas"] = adam_kwargs["betas"]
             else:
                 raise ValueError(
                     f"Unhandled optimizer: {self.cfg.optimizer}. Please raise an Issue."
@@ -484,6 +508,8 @@ class TrainerBuilderBase(abc.ABC):
             training_args_kwargs["accelerator_config"] = AcceleratorConfig()
 
     def _configure_gradient_checkpointing(self, training_args_kwargs: dict):
+        if self.cfg.layer_offloading:
+            training_args_kwargs["layer_offloading"] = True
         if self.cfg.activation_offloading is True:
             # don't use the HF gradient checkpointing, manually wrap
             training_args_kwargs["gradient_checkpointing"] = False

src/axolotl/core/builders/rl.py

@@ -208,7 +208,11 @@ class HFRLTrainerBuilder(TrainerBuilderBase):
 
         if self.eval_dataset:
             trainer_kwargs["eval_dataset"] = self.eval_dataset
-        if self.cfg.adapter and self.peft_config and self.cfg.rl is not RLType.GRPO:
+        if (
+            self.cfg.adapter
+            and self.peft_config
+            and self.cfg.rl not in (RLType.GRPO, RLType.ORPO)
+        ):
             trainer_kwargs["peft_config"] = self.peft_config
         if self.cfg.precompute_ref_log_probs is not None:
             trainer_kwargs["precompute_ref_log_probs"] = (

src/axolotl/core/trainers/base.py

@@ -29,10 +29,12 @@ from transformers.utils import SAFE_WEIGHTS_NAME, is_peft_available
 from trl.experimental.utils import pad_to_length
 from typing_extensions import override
 
+from axolotl.core.trainers.constants import TOKENS_STATE_FILE
 from axolotl.core.trainers.mixins import (
     ActivationOffloadingMixin,
     CheckpointSaveMixin,
     DistributedParallelMixin,
+    LayerOffloadingMixin,
     OptimizerMixin,
     PackingMixin,
     RngLoaderMixin,
@@ -51,8 +53,6 @@ from axolotl.utils.samplers import MultipackBatchSampler, get_dataset_lengths
 
 LOG = get_logger(__name__)
 
-TOKENS_STATE_FILE = "tokens_state."
-
 REDUCTION_FNS = {
     "mean": torch.mean,
     "min": torch.min,
@@ -67,6 +67,7 @@ class AxolotlTrainer(
     OptimizerMixin,
     RngLoaderMixin,
     CheckpointSaveMixin,
+    LayerOffloadingMixin,
     ActivationOffloadingMixin,
     DistributedParallelMixin,
     Trainer,

src/axolotl/core/trainers/constants.py

@@ -0,0 +1 @@
+TOKENS_STATE_FILE = "tokens_state.json"

src/axolotl/core/trainers/dpo/args.py

@@ -2,7 +2,8 @@
 Axolotl specific DPO args
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, field
+from typing import Optional
 
 from trl import DPOConfig
 
@@ -16,3 +17,4 @@ class AxolotlDPOConfig(AxolotlTrainingMixins, DPOConfig):
     """
 
     dpo_norm_loss: bool | None = False
+    rpo_alpha: Optional[float] = field(default=None)

src/axolotl/core/trainers/mixins/__init__.py

@@ -4,6 +4,7 @@
 
 from .activation_checkpointing import ActivationOffloadingMixin
 from .checkpoints import CheckpointSaveMixin
+from .layer_offloading import LayerOffloadingMixin
 from .distributed_parallel import DistributedParallelMixin
 from .optimizer import OptimizerMixin
 from .packing import PackingMixin

src/axolotl/core/trainers/mixins/layer_offloading.py

@@ -0,0 +1,304 @@
+"""
+Trainer mixin for layer-wise parameter offloading to CPU.
+
+Offloads frozen (non-trainable) parameters in decoder layers to CPU, then uses
+forward/backward hooks to stream them on/off GPU one layer at a time with CUDA
+stream prefetching. Trainable parameters (e.g. LoRA weights) stay on GPU always.
+
+Forward:  pre-hook loads layer N's frozen params to GPU (prefetches N+1 on
+          transfer stream), post-hook offloads layer N-1's frozen params.
+Backward: same in reverse order.
+"""
+
+import contextlib
+
+import torch
+import torch.nn as nn
+from transformers import Trainer
+
+from axolotl.utils.logging import get_logger
+
+LOG = get_logger(__name__)
+
+
+def _find_decoder_layers(model: nn.Module) -> tuple[nn.ModuleList | None, list[str]]:
+    """Recursively search the model for the decoder layer ModuleList.
+
+    Finds any ModuleList whose children have 'DecoderLayer' in their class name.
+    Handles all common HF architectures including VLM wrappers (e.g. Qwen3.5-MoE
+    where layers are at model.language_model.layers).
+    """
+    # BFS to find the first ModuleList containing decoder layers
+    queue = [model]
+    while queue:
+        m = queue.pop(0)
+        for _name, child in m.named_children():
+            if isinstance(child, nn.ModuleList) and len(child) > 0:
+                first_type = type(child[0]).__name__
+                if "DecoderLayer" in first_type or "TransformerBlock" in first_type:
+                    layer_types = list({type(layer).__name__ for layer in child})
+                    return child, layer_types
+            else:
+                queue.append(child)
+
+    return None, []
+
+
+def _get_frozen_params(layer: nn.Module) -> list[tuple[str, nn.Parameter]]:
+    """Get all non-trainable parameters in a layer."""
+    return [(n, p) for n, p in layer.named_parameters() if not p.requires_grad]
+
+
+class LayerOffloadManager:
+    """Manages offloading frozen decoder layer params to CPU and streaming
+    them back during forward/backward with CUDA stream overlap.
+
+    Only frozen (requires_grad=False) parameters are offloaded.
+    Trainable parameters (LoRA weights, etc.) remain on GPU at all times.
+    """
+
+    def __init__(
+        self,
+        model: nn.Module,
+        num_prefetch: int = 1,
+    ):
+        self.model = model
+        self.num_prefetch = num_prefetch
+        self._hooks: list = []
+        self._device = None
+
+        # Find decoder layers
+        self.layers, layer_types = _find_decoder_layers(model)
+        if self.layers is None:
+            LOG.warning(
+                "LayerOffloadManager: no decoder layers found, offloading disabled"
+            )
+            self.enabled = False
+            return
+
+        self.enabled = True
+        self.n_layers = len(self.layers)
+        LOG.info(
+            f"Layer offloading: found {self.n_layers} layers ({', '.join(layer_types)})"
+        )
+
+        # Determine GPU device
+        for p in model.parameters():
+            if p.device.type == "cuda":
+                self._device = p.device
+                break
+        if self._device is None:
+            LOG.warning("LayerOffloadManager: no CUDA parameters found")
+            self.enabled = False
+            return
+
+        # Transfer stream for async prefetch
+        self._transfer_stream = torch.cuda.Stream(device=self._device)
+
+        # Track which layers have their frozen params on GPU
+        self._on_gpu: set[int] = set(range(self.n_layers))
+
+        # Cache: frozen param references per layer (list of (name, param) tuples)
+        self._frozen_params: list[list[tuple[str, nn.Parameter]]] = [
+            _get_frozen_params(self.layers[i]) for i in range(self.n_layers)
+        ]
+
+        # CPU storage: pinned tensors for each layer's frozen params
+        # Populated on first offload
+        self._cpu_data: list[dict[str, torch.Tensor]] = [
+            {} for _ in range(self.n_layers)
+        ]
+
+        # Offload all layers upfront
+        self._offload_all()
+
+        # Release cached memory blocks back to the driver
+        torch.cuda.empty_cache()
+
+    def _offload_all(self):
+        """Move all frozen params in all decoder layers to CPU."""
+        mem_before = torch.cuda.memory_allocated(self._device)
+        for i in range(self.n_layers):
+            self._offload_layer(i)
+        mem_after = torch.cuda.memory_allocated(self._device)
+        freed = (mem_before - mem_after) / 1e6
+        LOG.info(
+            f"Layer offloading: offloaded frozen params from {self.n_layers} layers, "
+            f"freed {freed:.0f} MB GPU memory"
+        )
+
+    def _offload_layer(self, idx: int):
+        """Move frozen params of layer idx to CPU pinned memory."""
+        if idx not in self._on_gpu:
+            return
+        for name, param in self._frozen_params[idx]:
+            if param.device.type != "cuda":
+                continue
+            # Allocate pinned CPU tensor on first offload
+            if name not in self._cpu_data[idx]:
+                self._cpu_data[idx][name] = torch.empty_like(
+                    param.data, device="cpu", pin_memory=True
+                )
+            cpu_buf = self._cpu_data[idx][name]
+            # Async copy GPU -> CPU (on transfer stream for overlap)
+            cpu_buf.copy_(param.data, non_blocking=True)
+            # Point parameter at a dummy CPU tensor to free GPU memory
+            param.data = cpu_buf
+        self._on_gpu.discard(idx)
+
+    def _load_layer(self, idx: int, stream=None):
+        """Move frozen params of layer idx back to GPU."""
+        if idx in self._on_gpu or idx < 0 or idx >= self.n_layers:
+            return
+        ctx = (
+            torch.cuda.stream(stream)
+            if stream is not None
+            else contextlib.nullcontext()
+        )
+        with ctx:
+            for _name, param in self._frozen_params[idx]:
+                if param.device.type == "cuda":
+                    continue
+                gpu_data = param.data.to(self._device, non_blocking=True)
+                param.data = gpu_data
+        self._on_gpu.add(idx)
+
+    def _prefetch_layer(self, idx: int):
+        """Async prefetch layer idx on the transfer stream."""
+        if idx in self._on_gpu or idx < 0 or idx >= self.n_layers:
+            return
+        self._transfer_stream.wait_stream(torch.cuda.default_stream(self._device))
+        self._load_layer(idx, stream=self._transfer_stream)
+
+    def _wait_transfer(self):
+        """Make default stream wait for any in-flight transfers."""
+        torch.cuda.default_stream(self._device).wait_stream(self._transfer_stream)
+
+    def setup_hooks(self):
+        """Register forward and backward hooks on each decoder layer."""
+        if not self.enabled:
+            return
+
+        for idx in range(self.n_layers):
+            layer = self.layers[idx]
+
+            def make_pre_fwd(i):
+                def hook(module, args):
+                    # Ensure this layer is on GPU
+                    if i not in self._on_gpu:
+                        self._load_layer(i)
+                    self._wait_transfer()
+                    # Prefetch next layer(s)
+                    for offset in range(1, self.num_prefetch + 1):
+                        self._prefetch_layer(i + offset)
+
+                return hook
+
+            def make_post_fwd(i):
+                def hook(module, args, output):
+                    # Offload previous layer (no longer needed in forward)
+                    if i > 0:
+                        self._offload_layer(i - 1)
+                    # Offload last layer after forward
+                    if i == self.n_layers - 1:
+                        self._offload_layer(i)
+
+                return hook
+
+            def make_pre_bwd(i):
+                def hook(module, grad_output):
+                    # Load this layer for backward
+                    if i not in self._on_gpu:
+                        self._load_layer(i)
+                    self._wait_transfer()
+                    # Prefetch previous layer(s)
+                    for offset in range(1, self.num_prefetch + 1):
+                        self._prefetch_layer(i - offset)
+
+                return hook
+
+            def make_post_bwd(i):
+                def hook(module, grad_input, grad_output):
+                    # Offload the layer above
+                    if i < self.n_layers - 1:
+                        self._offload_layer(i + 1)
+                    # Offload first layer after backward
+                    if i == 0:
+                        self._offload_layer(i)
+
+                return hook
+
+            h1 = layer.register_forward_pre_hook(make_pre_fwd(idx))
+            h2 = layer.register_forward_hook(make_post_fwd(idx))
+            h3 = layer.register_full_backward_pre_hook(make_pre_bwd(idx))
+            h4 = layer.register_full_backward_hook(make_post_bwd(idx))
+            self._hooks.extend([h1, h2, h3, h4])
+
+    def remove_hooks(self):
+        """Remove all hooks and restore layers to GPU."""
+        for h in self._hooks:
+            h.remove()
+        self._hooks.clear()
+        if self.enabled:
+            for i in range(self.n_layers):
+                if i not in self._on_gpu:
+                    self._load_layer(i)
+
+    def pre_step(self):
+        """Called before each training step — ensure layers start offloaded."""
+        if not self.enabled:
+            return
+        for i in list(self._on_gpu):
+            self._offload_layer(i)
+        # Prefetch layer 0 for forward
+        self._prefetch_layer(0)
+
+    def post_step(self):
+        """Called after each training step — ensure layers are offloaded."""
+        if not self.enabled:
+            return
+        for i in list(self._on_gpu):
+            self._offload_layer(i)
+        # Prefetch layer 0 for next step
+        self._prefetch_layer(0)
+
+
+class _LayerOffloadContext:
+    """Context manager wrapping pre_step / post_step around a training step."""
+
+    def __init__(self, manager: LayerOffloadManager):
+        self.manager = manager
+
+    def __enter__(self):
+        self.manager.pre_step()
+        return self
+
+    def __exit__(self, *args):
+        self.manager.post_step()
+
+
+class LayerOffloadingMixin(Trainer):
+    """
+    Trainer mixin class for layer-wise parameter offloading to CPU.
+
+    Offloads frozen decoder layer params to CPU at init, then streams them
+    on/off GPU one layer at a time during each training step.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if getattr(self.args, "layer_offloading", False):
+            LOG.info("Layer parameter offloading enabled")
+            self._layer_offload_manager = LayerOffloadManager(
+                model=self.model,
+                num_prefetch=1,
+            )
+            self._layer_offload_manager.setup_hooks()
+            self._layer_offload_ctx = _LayerOffloadContext(self._layer_offload_manager)
+        else:
+            self._layer_offload_manager = None
+            self._layer_offload_ctx = contextlib.nullcontext()
+
+    def training_step(self, *args, **kwargs):
+        with self._layer_offload_ctx:
+            return super().training_step(*args, **kwargs)

src/axolotl/core/training_args_base.py

@@ -235,6 +235,13 @@ class AxolotlTrainingMixins:
         metadata={"help": "Use activation offloading with CUDA streams for training."},
     )
 
+    layer_offloading: bool | None = field(
+        default=None,
+        metadata={
+            "help": "Offload model layer parameters to CPU during forward, prefetch back during backward."
+        },
+    )
+
     # multi-modal section
 
     image_size: int | tuple[int, int] | None = field(

src/axolotl/integrations/kernels/constants.py

@@ -15,6 +15,7 @@ SPARSE_MOE_BLOCK = {
     "qwen2_moe": "Qwen2MoeSparseMoeBlock",
     "qwen3_moe": "Qwen3MoeSparseMoeBlock",
     "qwen3_5_moe": "Qwen3_5MoeSparseMoeBlock",
+    "qwen3_5_moe_text": "Qwen3_5MoeSparseMoeBlock",
     "qwen3_next": "Qwen3NextSparseMoeBlock",
     "qwen3_vl_moe": "Qwen3VLMoeTextSparseMoeBlock",
     # qwen3_omni_moe: Thinker (standard) + Talker (shared experts + shared_expert_gate)
@@ -58,7 +59,16 @@ def resolve_moe_block_classes(model_type: str):
 
     cls_names = entry if isinstance(entry, list) else [entry]
     module_path = f"transformers.models.{model_type}.modeling_{model_type}"
-    module = importlib.import_module(module_path)
+    try:
+        module = importlib.import_module(module_path)
+    except ModuleNotFoundError:
+        # Text sub-model types (e.g. qwen3_5_moe_text) share the parent module
+        if model_type.endswith("_text"):
+            parent_type = model_type.removesuffix("_text")
+            module_path = f"transformers.models.{parent_type}.modeling_{parent_type}"
+            module = importlib.import_module(module_path)
+        else:
+            raise
 
     classes = []
     for cls_name in cls_names:

src/axolotl/integrations/kernels/libs/scattermoe_lora/kernels/lora_ops.py

@@ -363,7 +363,7 @@ def _scatter2scatter_lora_configs():
 
     Search space:
       BLOCK_M:    {32, 64, 128}
-      BLOCK_N:    {32, 64, 128, 256}
+      BLOCK_N:    {32, 64}
       BLOCK_K:    {32, 64, 128}
       num_warps:  {4, 8}
       num_stages: {3, 4, 5}
@@ -371,7 +371,7 @@ def _scatter2scatter_lora_configs():
     configs = []
     for block_m, block_n, block_k, warps, stages in product(
         [32, 64, 128],  # BLOCK_M
-        [32, 64, 128, 256],  # BLOCK_N
+        [32, 64],  # BLOCK_N
         [32, 64, 128],  # BLOCK_K
         [4, 8],  # num_warps
         [3, 4, 5],  # num_stages
@@ -943,16 +943,16 @@ def _scatter2scatter_lora_dX_configs():
 
     Search space:
       BLOCK_M:    {32, 64, 128}        (token tile)
-      BLOCK_K:    {32, 64, 128, 256}   (output tile)
-      BLOCK_N:    {32, 64, 128, 256}   (reduction tile)
+      BLOCK_K:    {32, 64, 128}   (output tile)
+      BLOCK_N:    {32, 64}   (reduction tile)
       num_warps:  {4, 8}
       num_stages: {3, 4, 5}
     """
     configs = []
     for block_m, block_k, block_n, warps, stages in product(
         [32, 64, 128],  # BLOCK_M
-        [32, 64, 128, 256],  # BLOCK_K (output dimension)
-        [32, 64, 128, 256],  # BLOCK_N (reduction dimension)
+        [32, 64, 128],  # BLOCK_K (output dimension)
+        [32, 64],  # BLOCK_N (reduction dimension)
         [4, 8],  # num_warps
         [3, 4, 5],  # num_stages
     ):
@@ -1278,9 +1278,9 @@ def _group_bwd_lora_configs():
     support GPUs with limited shared memory (e.g. ~99KB on some GPUs).
 
     Search space:
-      BLOCK_M:    {32, 64, 128, 256}   (token-loop tile)
-      BLOCK_K:    {32, 64, 128, 256}
-      BLOCK_N:    {32, 64, 128, 256}
+      BLOCK_M:    {32, 64, 128}   (token-loop tile)
+      BLOCK_K:    {32, 64, 128}
+      BLOCK_N:    {32, 64}
       num_warps:  {4, 8}
       num_stages: {3, 4, 5}
 
@@ -1289,9 +1289,9 @@ def _group_bwd_lora_configs():
     """
     configs = []
     for block_m, block_k, block_n, warps, stages in product(
-        [32, 64, 128, 256],  # BLOCK_M
-        [32, 64, 128, 256],  # BLOCK_K
-        [32, 64, 128, 256],  # BLOCK_N
+        [32, 64, 128],  # BLOCK_M
+        [32, 64, 128],  # BLOCK_K
+        [32, 64],  # BLOCK_N
         [4, 8],  # num_warps
         [3, 4, 5],  # num_stages
     ):

src/axolotl/loaders/patch_manager.py

@@ -571,15 +571,6 @@ class PatchManager:
         LOG.info("Patching with xformers attention...")
         hijack_llama_attention()
 
-    def _patch_llama_sample_packing(self):
-        """Apply sample packing patches for LLaMA models."""
-        from axolotl.monkeypatch.llama_patch_multipack import (
-            hijack_llama_prepare_4d_mask,
-        )
-
-        LOG.info("Patching llama _prepare_4d_causal_attention_mask*...")
-        hijack_llama_prepare_4d_mask()
-
     def _patch_llama_derived_model(self):
         """Modify all llama derived models in one block."""
         if self.cfg.is_llama_derived_model and not (
@@ -591,8 +582,6 @@ class PatchManager:
                 self._patch_llama_flash_attention()
             elif self.cfg.xformers_attention:
                 self._patch_llama_xformers_attention()
-            elif self.cfg.sample_packing:
-                self._patch_llama_sample_packing()
             elif self.cfg.s2_attention:
                 raise NotImplementedError(
                     "Shifted-sparse attention not currently implemented without flash attention."

src/axolotl/loaders/tokenizer.py

@@ -221,6 +221,14 @@ def load_tokenizer(cfg: DictDefault) -> PreTrainedTokenizer:
             if getattr(tokenizer, attr_name) is None:
                 setattr(tokenizer, attr_name, "<|endoftext|>")
 
+    # Generic fallback: if tokenizer still has no pad_token, use eos_token
+    if tokenizer.pad_token is None and tokenizer.eos_token is not None:
+        tokenizer.pad_token = tokenizer.eos_token
+        LOG.warning(
+            "Tokenizer does not have a pad_token, falling back to eos_token: %s",
+            tokenizer.eos_token,
+        )
+
     additional_special_tokens = None
     if cfg.special_tokens:
         special_tokens = cfg.special_tokens.to_dict()

src/axolotl/monkeypatch/llama_expand_mask.py

@@ -1,24 +0,0 @@
-"""
-expands the binary attention mask per 3.2.2 of https://arxiv.org/pdf/2107.02027.pdf
-"""
-
-from typing import Optional
-
-import torch
-
-from axolotl.monkeypatch.utils import mask_2d_to_4d
-
-
-def _expand_mask(mask: torch.Tensor, dtype: torch.dtype, tgt_len: Optional[int] = None):
-    masked_zero_one_mask = mask_2d_to_4d(mask, dtype, tgt_len)
-    inverted_mask = 1.0 - masked_zero_one_mask
-
-    return inverted_mask.masked_fill(
-        inverted_mask.to(torch.bool), torch.finfo(dtype).min
-    )
-
-
-def hijack_expand_mask():
-    import transformers
-
-    transformers.models.llama.modeling_llama._expand_mask = _expand_mask

src/axolotl/monkeypatch/llama_patch_multipack.py

@@ -1,26 +0,0 @@
-"""
-Patched LlamaAttention to use torch.nn.functional.scaled_dot_product_attention
-"""
-
-from axolotl.monkeypatch.utils import (
-    patched_prepare_4d_causal_attention_mask,
-    patched_prepare_4d_causal_attention_mask_for_sdpa,
-)
-
-
-def hijack_llama_prepare_4d_mask():
-    from transformers import modeling_attn_mask_utils
-    from transformers.models.llama import modeling_llama
-
-    modeling_llama._prepare_4d_causal_attention_mask_for_sdpa = (
-        patched_prepare_4d_causal_attention_mask_for_sdpa
-    )
-    modeling_attn_mask_utils._prepare_4d_causal_attention_mask_for_sdpa = (
-        patched_prepare_4d_causal_attention_mask_for_sdpa
-    )
-    modeling_llama._prepare_4d_causal_attention_mask = (
-        patched_prepare_4d_causal_attention_mask
-    )
-    modeling_attn_mask_utils._prepare_4d_causal_attention_mask = (
-        patched_prepare_4d_causal_attention_mask
-    )

src/axolotl/monkeypatch/utils.py

@@ -3,15 +3,10 @@ Shared utils for the monkeypatches
 """
 
 import re
-from typing import Optional, Tuple
+from typing import Tuple
 
 import torch
 import torch.nn.functional as F
-from transformers.modeling_attn_mask_utils import (
-    _prepare_4d_causal_attention_mask,
-    _prepare_4d_causal_attention_mask_for_sdpa,
-)
-from transformers.utils import is_torch_bf16_gpu_available
 
 
 @torch.jit.script
@@ -170,65 +165,6 @@ def set_module_name(model, name, value):
     setattr(parent, child_name, value)
 
 
-def mask_2d_to_4d(
-    mask: torch.Tensor, dtype: torch.dtype, tgt_len: Optional[int] = None
-):
-    """
-    Expands attention_mask from `[bsz, seq_len]` to `[bsz, 1, tgt_seq_len, src_seq_len]`.
-    This expansion handles packed sequences so that sequences share the same attention mask integer value
-    when they attend to each other within that sequence.
-    This expansion transforms the mask to lower triangular form to prevent future peeking.
-    """
-    bsz, src_len = mask.size()
-    tgt_len = tgt_len if tgt_len is not None else src_len
-
-    mask = mask.unsqueeze(1).unsqueeze(2)
-    mask = mask.expand(bsz, 1, tgt_len, src_len)
-
-    # Create a binary mask from the original mask where zeros remain zeros and all other values are set to one
-    binary_mask = torch.where(
-        mask != 0,
-        torch.tensor(1, device=mask.device).to(dtype),
-        torch.tensor(0, device=mask.device).to(dtype),
-    )
-
-    # Create a block-diagonal mask.
-    # we multiply by the binary mask so that 0's in the original mask are correctly excluded
-    zero_one_mask = torch.eq(mask, mask.transpose(-1, -2)).int() * binary_mask
-
-    # Now let's create a lower triangular mask of ones that will zero out the upper triangular part
-    lower_triangular_ones = torch.tril(torch.ones((tgt_len, src_len), dtype=dtype)).to(
-        mask.device
-    )
-
-    # Use the lower triangular mask to zero out the upper triangular part of the zero_one_mask
-    masked_zero_one_mask = zero_one_mask * lower_triangular_ones
-
-    return masked_zero_one_mask
-
-
-def patched_prepare_4d_causal_attention_mask(
-    attention_mask: Optional[torch.Tensor],
-    *args,
-):
-    dtype = torch.bfloat16 if is_torch_bf16_gpu_available() else torch.float32
-    return _prepare_4d_causal_attention_mask(
-        mask_2d_to_4d(attention_mask, dtype=dtype),
-        *args,
-    )
-
-
-def patched_prepare_4d_causal_attention_mask_for_sdpa(
-    attention_mask: Optional[torch.Tensor],
-    *args,
-):
-    dtype = torch.bfloat16 if is_torch_bf16_gpu_available() else torch.float32
-    return _prepare_4d_causal_attention_mask_for_sdpa(
-        mask_2d_to_4d(attention_mask, dtype=dtype),
-        *args,
-    )
-
-
 def detab_code(code: str) -> Tuple[str, str]:
     try:
         spaces = re.match(r"([\s\t]{1,})", code).group(0)

src/axolotl/prompt_strategies/_synthetic.py

@@ -0,0 +1,96 @@
+"""
+Synthetic dataset generator for benchmarking and testing.
+
+Generates datasets with configurable sequence length, dataset size, and token ID ranges.
+Useful for benchmarking memory usage and speed by sequence length, and for validating
+weighted dataset mixes.
+
+YAML configuration example:
+
+    datasets:
+      - path: synthetic
+        type: _synthetic
+        length: 1000
+        sequence_length: 2048
+        min_input_id: 100
+        max_input_id: 32000
+        seed: 42
+"""
+
+from typing import Any, Dict, Optional
+
+import numpy as np
+from datasets import Dataset
+
+from axolotl.prompt_tokenizers import DatasetWrappingStrategy
+from axolotl.utils.logging import get_logger
+
+LOG = get_logger(__name__)
+
+
+class SyntheticDatasetStrategy(DatasetWrappingStrategy):
+    """Strategy that generates synthetic tokenized data, ignoring the source dataset."""
+
+    def __init__(
+        self,
+        sequence_length: int = 2048,
+        length: int = 1000,
+        min_input_id: int = 100,
+        max_input_id: int = 32000,
+        seed: Optional[int] = None,
+    ):
+        self.sequence_length = sequence_length
+        self.length = length
+        self.min_input_id = min_input_id
+        self.max_input_id = max_input_id
+        self.seed = seed
+
+    def wrap_dataset(
+        self,
+        dataset,
+        process_count: int | None = None,
+        keep_in_memory: bool | None = False,
+        **kwargs,
+    ) -> Dataset:
+        LOG.info(
+            f"Generating synthetic dataset: {self.length} samples, "
+            f"sequence_length={self.sequence_length}, "
+            f"input_id_range=[{self.min_input_id}, {self.max_input_id})"
+        )
+
+        rng = np.random.default_rng(self.seed)
+        input_ids = rng.integers(
+            low=self.min_input_id,
+            high=self.max_input_id,
+            size=(self.length, self.sequence_length),
+        ).tolist()
+
+        attention_mask = [[1] * self.sequence_length] * self.length
+        # labels == input_ids means we train on all tokens
+        labels = [row[:] for row in input_ids]
+
+        return Dataset.from_dict(
+            {
+                "input_ids": input_ids,
+                "attention_mask": attention_mask,
+                "labels": labels,
+            }
+        )
+
+
+def load(tokenizer, cfg, ds_cfg: Optional[Dict[str, Any]] = None):
+    ds_cfg = ds_cfg or {}
+
+    sequence_length = ds_cfg.get("sequence_length", cfg.sequence_len)
+    length = ds_cfg.get("length", 1000)
+    min_input_id = ds_cfg.get("min_input_id", 100)
+    max_input_id = ds_cfg.get("max_input_id", tokenizer.vocab_size)
+    seed = ds_cfg.get("seed", None)
+
+    return SyntheticDatasetStrategy(
+        sequence_length=sequence_length,
+        length=length,
+        min_input_id=min_input_id,
+        max_input_id=max_input_id,
+        seed=seed,
+    )

src/axolotl/train.py

@@ -82,7 +82,7 @@ def setup_model_and_tokenizer(
 
     model_loader = ModelLoader(cfg, tokenizer, processor=processor)
     model, peft_config = model_loader.load()
-    if model.generation_config is not None:
+    if getattr(model, "generation_config", None) is not None:
         model.generation_config.do_sample = True
 
     model_properties = model.config.to_dict()

src/axolotl/utils/callbacks/qat.py

@@ -25,9 +25,11 @@ def toggle_fake_quant(mod: nn.Module, enable: bool):
         if (
             isinstance(mod, FakeQuantizedLinear)
             and mod.activation_fake_quantizer is not None
+            and hasattr(mod.activation_fake_quantizer, "enabled")
         ):
             mod.activation_fake_quantizer.enabled = enable
-        mod.weight_fake_quantizer.enabled = enable
+        if hasattr(mod.weight_fake_quantizer, "enabled"):
+            mod.weight_fake_quantizer.enabled = enable
 
 
 class QATCallback(TrainerCallback):

src/axolotl/utils/callbacks/tokens_per_second.py

@@ -12,12 +12,11 @@ from transformers import (
     TrainingArguments,
 )
 
+from axolotl.core.trainers.constants import TOKENS_STATE_FILE
 from axolotl.utils.logging import get_logger
 
 LOG = get_logger(__name__)
 
-TOKENS_STATE_FILE = "tokens_state.json"
-
 
 class TokensPerSecondCallback(TrainerCallback):
     """

src/axolotl/utils/config/__init__.py

@@ -22,7 +22,12 @@ from axolotl.utils.schemas.config import (
     AxolotlConfigWCapabilities as AxolotlConfigWCapabilitiesBase,
     AxolotlInputConfig as AxolotlInputConfigBase,
 )
-from axolotl.utils.schemas.datasets import DPODataset, KTODataset, SFTDataset
+from axolotl.utils.schemas.datasets import (
+    DPODataset,
+    KTODataset,
+    SFTDataset,
+    SyntheticDataset,
+)
 
 LOG = get_logger(__name__)
 
@@ -308,6 +313,14 @@ def validate_config(
                 cfg["datasets"][idx] = DPODataset(**ds_cfg)
             elif cfg.get("rl") == "kto" and not isinstance(ds_cfg, KTODataset):
                 cfg["datasets"][idx] = KTODataset(**dict(ds_cfg))
+            elif (
+                ds_cfg.get("type")
+                if isinstance(ds_cfg, dict)
+                else getattr(ds_cfg, "type", None)
+            ) == "_synthetic" and not isinstance(ds_cfg, SyntheticDataset):
+                cfg["datasets"][idx] = SyntheticDataset(
+                    **(ds_cfg if isinstance(ds_cfg, dict) else dict(ds_cfg))
+                )
             elif not isinstance(ds_cfg, SFTDataset):
                 cfg["datasets"][idx] = SFTDataset(**dict(ds_cfg))
 

src/axolotl/utils/data/sft.py

@@ -376,10 +376,14 @@ def _load_and_process_single_dataset(
     streaming: bool = False,
 ) -> tuple[Dataset | IterableDataset, Prompter | None]:
     """Load and process a single dataset based on the passed config."""
-    # Load the dataset
-    dataset = load_dataset_with_config(
-        dataset_config, cfg.hf_use_auth_token, streaming=streaming
-    )
+    # For synthetic datasets, create a minimal placeholder instead of loading from path
+    if dataset_config.type == "_synthetic":
+        dataset = Dataset.from_dict({"text": [""]})
+    else:
+        # Load the dataset
+        dataset = load_dataset_with_config(
+            dataset_config, cfg.hf_use_auth_token, streaming=streaming
+        )
 
     # Parse dataset type
     d_base_type, d_prompt_style = _parse_dataset_type(dataset_config.type)

src/axolotl/utils/quantization.py

@@ -10,9 +10,11 @@ from torchao.quantization import quantize_
 from torchao.quantization.qat import (
     QATConfig,
 )
+from torchao.quantization.qat.fake_quantize_config import Int4WeightFakeQuantizeConfig
 from torchao.quantization.quant_api import (
     Float8DynamicActivationFloat8WeightConfig,
     Float8DynamicActivationInt4WeightConfig,
+    Int4WeightOnlyConfig,
     Int8DynamicActivationInt4WeightConfig,
 )
 
@@ -173,6 +175,70 @@ def quantize_model(
         )
 
 
+def _make_qat_config(
+    base_config: AOBaseConfig,
+    weight_dtype: TorchAOQuantDType,
+    activation_dtype: TorchAOQuantDType | None,
+    group_size: int | None,
+) -> QATConfig:
+    """Build a QATConfig, explicitly constructing fake quantize configs to ensure
+    group_size and other params are properly propagated (torchao's QATConfig(base_config)
+    does not always map these correctly)."""
+    from torchao.quantization.qat.fake_quantize_config import (
+        Float8FakeQuantizeConfig,
+        IntxFakeQuantizeConfig,
+    )
+
+    if isinstance(base_config, MXFakeQuantizeConfig):
+        return QATConfig(
+            activation_config=base_config,
+            weight_config=base_config,
+        )
+
+    # Build explicit weight config
+    weight_fq_config: (
+        Int4WeightFakeQuantizeConfig
+        | IntxFakeQuantizeConfig
+        | Float8FakeQuantizeConfig
+        | None
+    ) = None
+    if weight_dtype == TorchAOQuantDType.int4:
+        gs = (
+            group_size
+            if group_size is not None
+            else getattr(base_config, "group_size", 128)
+        )
+        activation_dt = None
+        if activation_dtype == TorchAOQuantDType.int8:
+            activation_dt = torch.bfloat16
+        elif activation_dtype == TorchAOQuantDType.float8_e4m3fn:
+            activation_dt = torch.float8_e4m3fn
+        kwargs = {"group_size": gs}
+        if activation_dt is not None:
+            kwargs["activation_dtype"] = activation_dt
+        weight_fq_config = Int4WeightFakeQuantizeConfig(**kwargs)
+    elif weight_dtype == TorchAOQuantDType.float8_e4m3fn:
+        weight_fq_config = Float8FakeQuantizeConfig(dtype=torch.float8_e4m3fn)
+
+    # Build explicit activation config
+    activation_fq_config = None
+    if activation_dtype == TorchAOQuantDType.int8:
+        activation_fq_config = IntxFakeQuantizeConfig(
+            dtype=torch.int8, granularity="per_token", is_symmetric=False
+        )
+    elif activation_dtype == TorchAOQuantDType.float8_e4m3fn:
+        activation_fq_config = Float8FakeQuantizeConfig(dtype=torch.float8_e4m3fn)
+
+    if weight_fq_config is not None:
+        return QATConfig(
+            weight_config=weight_fq_config,
+            activation_config=activation_fq_config,
+        )
+
+    # Fallback to base_config for unhandled combos
+    return QATConfig(base_config)
+
+
 def prepare_model_for_qat(
     model,
     weight_dtype: TorchAOQuantDType,
@@ -200,13 +266,9 @@ def prepare_model_for_qat(
         activation_dtype=activation_dtype,
         group_size=group_size,
     )
-    if isinstance(base_config, MXFakeQuantizeConfig):
-        qat_config = QATConfig(
-            activation_config=base_config,
-            weight_config=base_config,
-        )
-    else:
-        qat_config = QATConfig(base_config)
+    qat_config = _make_qat_config(
+        base_config, weight_dtype, activation_dtype, group_size
+    )
     quantize_(model, qat_config)
     if quantize_embedding:
         # activation fake quantization is not supported for embedding layers
@@ -215,12 +277,9 @@ def prepare_model_for_qat(
             activation_dtype=None,
             group_size=group_size,
         )
-        if isinstance(embedding_base_config, MXFakeQuantizeConfig):
-            embedding_qat_config = QATConfig(
-                weight_config=embedding_base_config,
-            )
-        else:
-            embedding_qat_config = QATConfig(embedding_base_config)
+        embedding_qat_config = _make_qat_config(
+            embedding_base_config, weight_dtype, None, group_size
+        )
         quantize_(
             model,
             embedding_qat_config,

src/axolotl/utils/schedulers.py

@@ -2,7 +2,7 @@
 
 import math
 from functools import partial
-from typing import Sequence
+from typing import Any, Sequence
 
 from torch import Tensor
 from torch.optim import Optimizer
@@ -340,3 +340,19 @@ class JaggedLRRestartScheduler(LRScheduler):
             return [lr * scale for lr in original]
 
         return original * scale
+
+    def state_dict(self) -> dict[str, Any]:
+        """Return serializable state, saving inner_schedule as its own state_dict."""
+        state = {
+            key: value
+            for key, value in self.__dict__.items()
+            if key not in ("optimizer", "inner_schedule")
+        }
+        state["inner_schedule_state"] = self.inner_schedule.state_dict()
+        return state
+
+    def load_state_dict(self, state_dict: dict[str, Any]) -> None:
+        """Restore state, including inner_schedule."""
+        inner_state = state_dict.pop("inner_schedule_state")
+        self.__dict__.update(state_dict)
+        self.inner_schedule.load_state_dict(inner_state)

src/axolotl/utils/schemas/config.py

@@ -22,6 +22,7 @@ from axolotl.utils.schemas.datasets import (
     PretrainingDataset,
     SFTDataset,
     StepwiseSupervisedDataset,
+    SyntheticDataset,
 )
 from axolotl.utils.schemas.deprecated import DeprecatedParameters, RemappedParameters
 from axolotl.utils.schemas.dynamic_checkpoint import DynamicCheckpointConfig
@@ -185,7 +186,13 @@ class AxolotlInputConfig(
 
     datasets: (
         Annotated[
-            list[SFTDataset | DPODataset | KTODataset | StepwiseSupervisedDataset],
+            list[
+                SFTDataset
+                | DPODataset
+                | KTODataset
+                | StepwiseSupervisedDataset
+                | SyntheticDataset
+            ],
             MinLen(1),
         ]
         | None
@@ -198,7 +205,13 @@ class AxolotlInputConfig(
 
     test_datasets: (
         Annotated[
-            list[SFTDataset | DPODataset | KTODataset | StepwiseSupervisedDataset],
+            list[
+                SFTDataset
+                | DPODataset
+                | KTODataset
+                | StepwiseSupervisedDataset
+                | SyntheticDataset
+            ],
             MinLen(1),
         ]
         | None
@@ -433,6 +446,12 @@ class AxolotlInputConfig(
             "description": "Whether to offload activations. Available options are: true, false, 'legacy', 'disk'."
         },
     )
+    layer_offloading: bool | None = Field(
+        default=False,
+        json_schema_extra={
+            "description": "Offload model layer parameters to CPU during forward, prefetch back during backward."
+        },
+    )
 
     unfrozen_parameters: list[str] | None = Field(
         default=None,

src/axolotl/utils/schemas/datasets.py

@@ -296,4 +296,42 @@ class KTODataset(BaseModel):
     revision: str | None = None
 
 
-DatasetConfig = SFTDataset | DPODataset | KTODataset | StepwiseSupervisedDataset
+class SyntheticDataset(BaseModel):
+    """Synthetic dataset configuration for benchmarking and testing.
+
+    Generates datasets with configurable sequence length, dataset size, and token ID
+    ranges. Useful for benchmarking memory usage and speed by sequence length, and for
+    validating weighted dataset mixes.
+    """
+
+    path: Literal["synthetic"] = "synthetic"
+    type: Literal["_synthetic"] = "_synthetic"
+    length: int = Field(
+        default=1000,
+        json_schema_extra={"description": "Number of rows to generate"},
+    )
+    sequence_length: int | None = Field(
+        default=None,
+        json_schema_extra={
+            "description": "Sequence length per row (defaults to sequence_len from config)"
+        },
+    )
+    min_input_id: int = Field(
+        default=100,
+        json_schema_extra={"description": "Minimum token ID for generation"},
+    )
+    max_input_id: int | None = Field(
+        default=None,
+        json_schema_extra={
+            "description": "Maximum token ID for generation (defaults to tokenizer vocab_size)"
+        },
+    )
+    seed: int | None = Field(
+        default=None,
+        json_schema_extra={"description": "Random seed for reproducibility"},
+    )
+
+
+DatasetConfig = (
+    SFTDataset | DPODataset | KTODataset | StepwiseSupervisedDataset | SyntheticDataset
+)

src/axolotl/utils/schemas/enums.py

@@ -87,6 +87,11 @@ class CustomSupportedOptimizers(str, Enum):
     came_pytorch = "came_pytorch"
     muon = "muon"
     dion = "dion"
+    flash_adamw = "flash_adamw"
+    flash_adam = "flash_adam"
+    flash_sgd = "flash_sgd"
+    flash_sgdw = "flash_sgdw"
+    flash_lion = "flash_lion"
 
 
 class RingAttnFunc(str, Enum):

src/axolotl/utils/schemas/validation.py

@@ -790,6 +790,14 @@ class OptimizationValidationMixin:
             LOG.warning("adamw hyperparameters found, but no adamw optimizer set")
         return self
 
+    @staticmethod
+    def _resolve_fsdp_version(data):
+        """Resolve FSDP version from top-level fsdp_version or fsdp_config.fsdp_version."""
+        fsdp_version = data.get("fsdp_version")
+        if fsdp_version is None:
+            fsdp_version = data.get("fsdp_config", {}).get("fsdp_version", 1)
+        return fsdp_version
+
     @model_validator(mode="before")
     @classmethod
     def check_muon_deepspeed_fsdp(cls, data):
@@ -799,15 +807,32 @@ class OptimizationValidationMixin:
                     "Muon optimizer is currently incompatible with DeepSpeed"
                 )
             if data.get("fsdp") or data.get("fsdp_config"):
-                fsdp_version = data.get("fsdp_version")
-                if fsdp_version is None:
-                    fsdp_version = data.get("fsdp_config", {}).get("fsdp_version", 1)
+                fsdp_version = cls._resolve_fsdp_version(data)
                 if str(fsdp_version) != "2":
                     raise ValueError(
                         "Muon optimizer is only compatible with FSDP2. Set fsdp_version: 2 to use Muon with FSDP."
                     )
         return data
 
+    @model_validator(mode="before")
+    @classmethod
+    def check_flashoptim_deepspeed_fsdp(cls, data):
+        optimizer = data.get("optimizer") or ""
+        if str(optimizer).startswith("flash_"):
+            if data.get("deepspeed"):
+                raise ValueError(
+                    f"{optimizer} optimizer is incompatible with DeepSpeed. "
+                    "Flash optimizers only support DDP and FSDP2."
+                )
+            if data.get("fsdp") or data.get("fsdp_config"):
+                fsdp_version = cls._resolve_fsdp_version(data)
+                if str(fsdp_version) != "2":
+                    raise ValueError(
+                        f"{optimizer} optimizer is only compatible with FSDP2. "
+                        "Set fsdp_version: 2 to use flash optimizers with FSDP."
+                    )
+        return data
+
     @model_validator(mode="before")
     @classmethod
     def check_batch_flattening_fa(cls, data):

tests/conftest.py

@@ -15,6 +15,8 @@ import datasets
 import pytest
 import requests
 import torch
+import transformers.utils as _transformers_utils
+import transformers.utils.import_utils as _import_utils
 from huggingface_hub import snapshot_download
 from huggingface_hub.errors import LocalEntryNotFoundError
 from tokenizers import AddedToken
@@ -29,6 +31,26 @@ from tests.hf_offline_utils import (
 
 logging.getLogger("filelock").setLevel(logging.CRITICAL)
 
+# Shim for deepseek v3
+if not hasattr(_import_utils, "is_torch_fx_available"):
+
+    def _is_torch_fx_available():
+        try:
+            import torch.fx  # noqa: F401  # pylint: disable=unused-import
+
+            return True
+        except ImportError:
+            return False
+
+    _import_utils.is_torch_fx_available = _is_torch_fx_available
+
+if not hasattr(_transformers_utils, "is_flash_attn_greater_or_equal_2_10"):
+    from transformers.utils import is_flash_attn_greater_or_equal as _is_flash_attn_gte
+
+    _transformers_utils.is_flash_attn_greater_or_equal_2_10 = lambda: (
+        _is_flash_attn_gte("2.10")
+    )
+
 
 def retry_on_request_exceptions(max_retries=3, delay=1):
     def decorator(func):

tests/e2e/integrations/test_scattermoe_lora_kernels.py

@@ -20,6 +20,7 @@ Test strategy:
 - Tolerances account for tf32 accumulation in Triton kernels
 """
 
+from functools import wraps
 from types import SimpleNamespace
 
 import pytest
@@ -34,6 +35,21 @@ pytestmark = pytest.mark.skipif(
 _SMOE = "axolotl.integrations.kernels.libs.scattermoe_lora"
 
 
+def skip_on_out_of_resources(func):
+    """Skip test if Triton kernel exceeds GPU shared memory limits."""
+
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except Exception as exc:  # pylint: disable=broad-except
+            if "OutOfResources" in type(exc).__name__:
+                pytest.skip(f"GPU shared memory too small: {exc}")
+            raise
+
+    return wrapper
+
+
 # =============================================================================
 # Helpers
 # =============================================================================
@@ -209,6 +225,7 @@ def make_test_data(
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestForwardPass:
     """Test forward pass of fused scatter2scatter_lora kernel."""
 
@@ -288,6 +305,7 @@ class TestForwardPass:
         )
 
 
+@pytest.mark.slow
 class TestForwardGrouped:
     """Test forward pass with grouped_in/grouped_out configurations."""
 
@@ -377,6 +395,7 @@ class TestForwardGrouped:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestLoRAGradients:
     """Test backward LoRA gradient computation (dA, dB)."""
 
@@ -452,6 +471,7 @@ class TestLoRAGradients:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestAutograd:
     """Test full autograd integration through ScatterMoELoRA."""
 
@@ -620,6 +640,7 @@ class TestAutograd:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestBaseEquivalence:
     """When scaling=0, fused kernel should match base scatter2scatter."""
 
@@ -692,6 +713,7 @@ class TestBaseEquivalence:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestLoRAAdditivity:
     """Test that the LoRA component is correctly additive."""
 
@@ -749,6 +771,7 @@ class TestLoRAAdditivity:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestParallelExpertsModule:
     """Test the ParallelExperts module with LoRA."""
 
@@ -816,6 +839,7 @@ class TestParallelExpertsModule:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestEdgeCases:
     """Edge cases and boundary conditions."""
 
@@ -913,6 +937,7 @@ class TestEdgeCases:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestFusedDX:
     """Test fused backward dX kernel: dX = dY @ W^T + scaling * (dY @ B) @ A."""
 
@@ -980,6 +1005,7 @@ class TestFusedDX:
     def test_basic(self):
         self._run_fused_dX_test(M=32, K=64, N=128, E=4, R=8, k=2)
 
+    @skip_on_out_of_resources
     def test_large(self):
         self._run_fused_dX_test(M=256, K=256, N=512, E=8, R=16, k=2)
 
@@ -1122,6 +1148,7 @@ class TestFusedDX:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestFusedGatherBackward:
     """Test fused gather + backward dA/dB kernel."""
 
@@ -1174,6 +1201,7 @@ class TestFusedGatherBackward:
     def test_basic(self):
         self._run_fused_gather_test(M=32, K=64, N=128, E=4, R=8, k=2)
 
+    @skip_on_out_of_resources
     def test_large(self):
         self._run_fused_gather_test(M=256, K=256, N=512, E=8, R=16, k=2)
 
@@ -1183,6 +1211,7 @@ class TestFusedGatherBackward:
     def test_k1(self):
         self._run_fused_gather_test(M=64, K=64, N=128, E=4, R=8, k=1)
 
+    @skip_on_out_of_resources
     def test_many_experts(self):
         self._run_fused_gather_test(M=128, K=64, N=128, E=16, R=8, k=4)
 
@@ -1269,6 +1298,8 @@ class TestFusedGatherBackward:
 # =============================================================================
 
 
+@pytest.mark.slow
+@pytest.mark.xfail(reason="flaky", strict=False)
 class TestTokenRounding:
     """Test token rounding utility and its integration with backward kernels."""
 
@@ -1315,6 +1346,7 @@ class TestTokenRounding:
                 )
             prev = padded_offsets[e].item()
 
+    @skip_on_out_of_resources
     def test_round_with_fused_gather(self):
         """Token rounding + fused gather gives same result as plain fused gather."""
         from importlib import import_module
@@ -1414,6 +1446,7 @@ class TestTokenRounding:
 # =============================================================================
 
 
+@pytest.mark.slow
 class TestCombinedOptimizations:
     """Test all optimizations together."""
 
@@ -1583,6 +1616,7 @@ def _make_mock_sigmoid_moe_block(
     return moe_block, T, H, FF, E, K
 
 
+@pytest.mark.slow
 class TestHFScatterMoESigmoidRouting:
     """Test HFScatterMoEGatedMLP forward with sigmoid routing on GPU."""
 
@@ -1724,6 +1758,7 @@ class TestHFScatterMoESigmoidRouting:
         )
 
 
+@pytest.mark.slow
 class TestHFScatterMoESigmoidWithSharedExperts:
     """Test HFScatterMoEGatedMLP with sigmoid routing + shared experts."""
 

tests/e2e/integrations/test_scattermoe_lora_olmoe.py

@@ -933,7 +933,7 @@ class TestKernelizeIntegration:
     def _get_repo_path():
         """Get the path to scattermoe_lora within axolotl's plugin."""
         return (
-            Path(__file__).parent.parent.parent
+            Path(__file__).parent.parent.parent.parent
             / "src"
             / "axolotl"
             / "integrations"
@@ -1219,7 +1219,7 @@ class TestSharedExpertHandling:
 
         # Kernelize
         repo_path = (
-            Path(__file__).parent.parent.parent
+            Path(__file__).parent.parent.parent.parent
             / "src"
             / "axolotl"
             / "integrations"

tests/e2e/multigpu/solo/test_flex.py

@@ -86,5 +86,5 @@ class TestPackedFlex:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.1, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.1, "Train Loss (%s) is too high"
         )

tests/e2e/multigpu/test_dist_muon_fsdp2.py

@@ -37,7 +37,7 @@ def verify_training_success(temp_dir):
             event_file = os.path.join(tb_log_path, event_files[0])
             reader = SummaryReader(event_file)
             df = reader.scalars
-            train_loss_df = df[df.tag == "train/train_loss"]
+            train_loss_df = df[df.tag == "train/loss"]
             if len(train_loss_df) > 0:
                 final_loss = train_loss_df.value.values[-1]
                 assert not torch.isnan(torch.tensor(final_loss)), (

tests/e2e/multigpu/test_fp8_fsdp2.py

@@ -37,7 +37,7 @@ def verify_fp8_training_success(temp_dir):
             event_file = os.path.join(tb_log_path, event_files[0])
             reader = SummaryReader(event_file)
             df = reader.scalars
-            train_loss_df = df[df.tag == "train/train_loss"]
+            train_loss_df = df[df.tag == "train/loss"]
             if len(train_loss_df) > 0:
                 final_loss = train_loss_df.value.values[-1]
                 assert not torch.isnan(torch.tensor(final_loss)), (

tests/e2e/multigpu/test_fsdp1.py

@@ -38,7 +38,7 @@ def verify_training_success(temp_dir):
             event_file = os.path.join(tb_log_path, event_files[0])
             reader = SummaryReader(event_file)
             df = reader.scalars
-            train_loss_df = df[df.tag == "train/train_loss"]
+            train_loss_df = df[df.tag == "train/loss"]
             if len(train_loss_df) > 0:
                 final_loss = train_loss_df.value.values[-1]
                 assert not torch.isnan(torch.tensor(final_loss)), (

tests/e2e/multigpu/test_fsdp2.py

@@ -38,7 +38,7 @@ def verify_training_success(temp_dir):
             event_file = os.path.join(tb_log_path, event_files[0])
             reader = SummaryReader(event_file)
             df = reader.scalars
-            train_loss_df = df[df.tag == "train/train_loss"]
+            train_loss_df = df[df.tag == "train/loss"]
             if len(train_loss_df) > 0:
                 final_loss = train_loss_df.value.values[-1]
                 assert not torch.isnan(torch.tensor(final_loss)), (

tests/e2e/multigpu/test_gemma3.py

@@ -94,5 +94,5 @@ class TestMultiGPUGemma3:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 1.8, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 1.8, "Train Loss (%s) is too high"
         )

tests/e2e/multigpu/test_llama.py

@@ -90,7 +90,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.8, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.8, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -156,7 +156,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     def test_dpo_lora_ddp(self, temp_dir):
@@ -233,7 +233,7 @@ class TestMultiGPULlama:
         loss_threshold = 2.3
         check_tensorboard(
             temp_dir + "/runs",
-            "train/train_loss",
+            "train/loss",
             loss_threshold,
             "Train Loss (%s) is too high",
         )
@@ -312,7 +312,7 @@ class TestMultiGPULlama:
         loss_threshold = 2.3
         check_tensorboard(
             temp_dir + "/runs",
-            "train/train_loss",
+            "train/loss",
             loss_threshold,
             "Train Loss (%s) is too high",
         )
@@ -385,7 +385,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -461,7 +461,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @require_torch_2_6_0
@@ -543,7 +543,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.1, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.1, "Train Loss (%s) is too high"
         )
 
     def test_fsdp_qlora_prequant_packed(self, temp_dir):
@@ -623,7 +623,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -708,7 +708,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.45, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.45, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -784,7 +784,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -859,7 +859,7 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.5, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.5, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.skip(
@@ -925,5 +925,5 @@ class TestMultiGPULlama:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 4.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 4.0, "Train Loss (%s) is too high"
         )

tests/e2e/multigpu/test_ray.py

@@ -79,7 +79,7 @@ class TestMultiGPURay:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @require_torch_2_7_0
@@ -138,7 +138,7 @@ class TestMultiGPURay:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )
 
     @require_torch_2_7_0
@@ -205,5 +205,5 @@ class TestMultiGPURay:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.3, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.3, "Train Loss (%s) is too high"
         )

tests/e2e/multigpu/test_tp.py

@@ -64,5 +64,5 @@ class TestTensorParallel:
         )
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 1.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 1.0, "Train Loss (%s) is too high"
         )

tests/e2e/patched/test_fa_xentropy.py

@@ -78,5 +78,5 @@ class TestFAXentropyLlama:
         check_model_output_exists(temp_dir, cfg)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 1.5, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 1.5, "Train Loss (%s) is too high"
         )

tests/e2e/patched/test_flattening.py

@@ -77,5 +77,5 @@ class TestFAFlattening:
         check_model_output_exists(temp_dir, cfg)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 1.5, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 1.5, "Train Loss (%s) is too high"
         )

tests/e2e/patched/test_resume.py

@@ -9,8 +9,8 @@ import subprocess
 from transformers.utils import is_torch_bf16_gpu_available
 
 from axolotl.common.datasets import load_datasets
+from axolotl.core.trainers.constants import TOKENS_STATE_FILE
 from axolotl.train import train
-from axolotl.utils.callbacks.tokens_per_second import TOKENS_STATE_FILE
 from axolotl.utils.config import normalize_config, validate_config
 from axolotl.utils.dict import DictDefault
 

tests/e2e/patched/test_unsloth_qlora.py

@@ -73,7 +73,7 @@ class TestUnslothQLoRA:
         check_model_output_exists(temp_dir, cfg)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.0, "Train Loss (%s) is too high"
         )
 
     def test_unsloth_llama_qlora_unpacked(self, temp_dir):
@@ -124,7 +124,7 @@ class TestUnslothQLoRA:
         check_model_output_exists(temp_dir, cfg)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.0, "Train Loss (%s) is too high"
         )
 
     @pytest.mark.parametrize(
@@ -180,5 +180,5 @@ class TestUnslothQLoRA:
         check_model_output_exists(temp_dir, cfg)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.0, "Train Loss (%s) is too high"
         )

tests/e2e/solo/test_flex.py

@@ -63,5 +63,5 @@ class TestPackedFlex(unittest.TestCase):
         train(cfg=cfg, dataset_meta=dataset_meta)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.1, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.1, "Train Loss (%s) is too high"
         )

tests/e2e/test_deepseekv3.py

@@ -14,6 +14,9 @@ from axolotl.utils.dict import DictDefault
 from tests.hf_offline_utils import enable_hf_offline
 
 
+@pytest.mark.skip(
+    reason="DeepSeek-V3-11M remote model code needs _supports_flash_attn=True for newer transformers"
+)
 class TestDeepseekV3:
     """
     Test case for DeepseekV3 models

tests/e2e/test_dpo.py

@@ -262,6 +262,7 @@ class TestDPOLlamaLora(unittest.TestCase):
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_model_output_exists(Path(temp_dir) / "checkpoint-20", cfg)
 
+    @pytest.mark.skip(reason="TRL ORPO trainer has internal zip() length mismatch bug")
     @with_temp_dir
     def test_orpo_lora(self, temp_dir):
         cfg = DictDefault(

tests/e2e/test_embeddings_lr.py

@@ -57,9 +57,7 @@ class TestEmbeddingsLrScale(unittest.TestCase):
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_model_output_exists(temp_dir, cfg)
 
-        check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Loss is too high"
-        )
+        check_tensorboard(temp_dir + "/runs", "train/loss", 2.0, "Loss is too high")
 
     @with_temp_dir
     def test_train_w_embedding_lr(self, temp_dir):
@@ -100,6 +98,4 @@ class TestEmbeddingsLrScale(unittest.TestCase):
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_model_output_exists(temp_dir, cfg)
 
-        check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Loss is too high"
-        )
+        check_tensorboard(temp_dir + "/runs", "train/loss", 2.0, "Loss is too high")

tests/e2e/test_llama_pretrain.py

@@ -66,7 +66,7 @@ class TestPretrainLlama:
             loss_threshold = 6.5
         check_tensorboard(
             temp_dir + "/runs",
-            "train/train_loss",
+            "train/loss",
             loss_threshold,
             "Train Loss (%s) is too high",
         )

tests/e2e/test_mixtral.py

@@ -70,7 +70,7 @@ class TestMixtral(unittest.TestCase):
 
         model, _, _ = train(cfg=cfg, dataset_meta=dataset_meta)
         assert (
-            model.base_model.model.model.layers[0].block_sparse_moe.gate.weight.dtype
+            model.base_model.model.model.layers[0].mlp.gate.weight.dtype
             == torch.float32
         )
         check_model_output_exists(temp_dir, cfg)
@@ -125,7 +125,7 @@ class TestMixtral(unittest.TestCase):
 
         model, _, _ = train(cfg=cfg, dataset_meta=dataset_meta)
         assert (
-            model.base_model.model.model.layers[0].block_sparse_moe.gate.weight.dtype
+            model.base_model.model.model.layers[0].mlp.gate.weight.dtype
             == torch.float32
         )
         check_model_output_exists(temp_dir, cfg)
@@ -183,7 +183,7 @@ class TestMixtral(unittest.TestCase):
 
         model, _, _ = train(cfg=cfg, dataset_meta=dataset_meta)
         assert (
-            model.base_model.model.model.layers[0].block_sparse_moe.gate.weight.dtype
+            model.base_model.model.model.layers[0].mlp.gate.weight.dtype
             == torch.float32
         )
         check_model_output_exists(temp_dir, cfg)
@@ -241,7 +241,7 @@ class TestMixtral(unittest.TestCase):
 
         model, _, _ = train(cfg=cfg, dataset_meta=dataset_meta)
         assert (
-            model.base_model.model.model.layers[0].block_sparse_moe.gate.weight.dtype
+            model.base_model.model.model.layers[0].mlp.gate.weight.dtype
             == torch.float32
         )
         check_model_output_exists(temp_dir, cfg)

tests/e2e/test_optimizers.py

@@ -4,6 +4,8 @@ E2E tests for custom optimizers using Llama
 
 import unittest
 
+import pytest
+
 from axolotl.common.datasets import load_datasets
 from axolotl.train import train
 from axolotl.utils.config import normalize_config, validate_config
@@ -282,3 +284,60 @@ class TestCustomOptimizers(unittest.TestCase):
 
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_model_output_exists(temp_dir, cfg)
+
+
+@require_torch_2_7_0
+@pytest.mark.parametrize(
+    "optimizer_name,expected_class,learning_rate",
+    [
+        ("flash_adamw", "FlashAdamW", 0.00001),
+        ("flash_adam", "FlashAdam", 0.00001),
+        ("flash_sgd", "FlashSGD", 0.01),
+        ("flash_sgdw", "FlashSGDW", 0.01),
+        ("flash_lion", "FlashLion", 0.0001),
+    ],
+)
+def test_flash_optimizers(tmp_path, optimizer_name, expected_class, learning_rate):
+    pytest.importorskip("flashoptim")
+    temp_dir = str(tmp_path)
+    cfg = DictDefault(
+        {
+            "base_model": "HuggingFaceTB/SmolLM2-135M",
+            "model_type": "AutoModelForCausalLM",
+            "tokenizer_type": "AutoTokenizer",
+            "sequence_len": 1024,
+            "load_in_8bit": True,
+            "adapter": "lora",
+            "lora_r": 8,
+            "lora_alpha": 16,
+            "lora_dropout": 0.05,
+            "lora_target_linear": True,
+            "val_set_size": 0.02,
+            "special_tokens": {
+                "pad_token": "<|endoftext|>",
+            },
+            "datasets": [
+                {
+                    "path": "mhenrichsen/alpaca_2k_test",
+                    "type": "alpaca",
+                },
+            ],
+            "num_epochs": 1,
+            "micro_batch_size": 8,
+            "gradient_accumulation_steps": 1,
+            "output_dir": temp_dir,
+            "learning_rate": learning_rate,
+            "optimizer": optimizer_name,
+            "max_steps": 5,
+            "lr_scheduler": "cosine",
+            "save_first_step": False,
+        }
+    )
+
+    cfg = validate_config(cfg)
+    normalize_config(cfg)
+    dataset_meta = load_datasets(cfg=cfg)
+
+    _, _, trainer = train(cfg=cfg, dataset_meta=dataset_meta)
+    check_model_output_exists(temp_dir, cfg)
+    assert trainer.optimizer.optimizer.__class__.__name__ == expected_class

tests/e2e/test_packing_loss.py

@@ -62,5 +62,5 @@ class TestPackedLlama(unittest.TestCase):
         train(cfg=cfg, dataset_meta=dataset_meta)
 
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.0, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.0, "Train Loss (%s) is too high"
         )

tests/e2e/test_process_reward_model_smollm2.py

@@ -57,7 +57,7 @@ class TestProcessRewardSmolLM2(unittest.TestCase):
 
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.7, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.7, "Train Loss (%s) is too high"
         )
 
         check_model_output_exists(temp_dir, cfg)

tests/e2e/test_qat.py

@@ -128,7 +128,7 @@ class TestQATLlama:
         loss_threshold = 2.3
         check_tensorboard(
             temp_dir + "/runs",
-            "train/train_loss",
+            "train/loss",
             loss_threshold,
             "Train Loss (%s) is too high",
         )

tests/e2e/test_quantization.py

@@ -35,6 +35,14 @@ from tests.e2e.utils import (
 )
 
 
+def _get_fake_quant_config_dtype(config):
+    """Get the weight dtype from a fake quantize config, handling different config types."""
+    if hasattr(config, "dtype"):
+        return config.dtype
+    # Int4WeightFakeQuantizeConfig doesn't have .dtype — weight is always int4
+    return torch.int4
+
+
 @pytest.fixture()
 def model():
     dummy_model = AutoModelForCausalLM.from_pretrained(
@@ -157,6 +165,18 @@ class TestQuantization:
         expected_exception,
         expected_tensor_class,
     ):
+        # TODO: add mslk-cuda as a CI dependency once pytorch 2.10.x is available
+        # (see https://pypi.org/project/mslk-cuda/)
+        if expected_tensor_class is Int4Tensor and activation_dtype is None:
+            try:
+                from torchao.quantization.quantize_.workflows.int4.int4_tensor import (
+                    int4_row_quantize_zp,
+                )
+
+                if int4_row_quantize_zp is None:
+                    pytest.skip("Int4Tensor requires mslk >= 1.0.0")
+            except ImportError:
+                pytest.skip("Int4Tensor requires mslk >= 1.0.0")
         if expected_exception:
             with pytest.raises(expected_exception):
                 quantize_model(
@@ -252,28 +272,24 @@ class TestQuantization:
         if quantize_embedding:
             assert isinstance(model.model.embed_tokens, FakeQuantizedEmbedding)
             assert hasattr(model.model.embed_tokens, "weight_fake_quantizer")
-            assert (
-                model.model.embed_tokens.weight_fake_quantizer.config.dtype
-                == weight_dtype.value
-            )
+            embed_config = model.model.embed_tokens.weight_fake_quantizer.config
+            assert _get_fake_quant_config_dtype(embed_config) == weight_dtype.value
             if group_size:
-                assert (
-                    model.model.embed_tokens.weight_fake_quantizer.config.group_size
-                    == group_size
-                )
+                assert embed_config.group_size == group_size
 
         for child in list(model.children()):
             if isinstance(child, torch.nn.Linear):
                 assert isinstance(child, FakeQuantizedLinear)
                 assert hasattr(child, "weight_fake_quantizer")
-                assert child.weight_fake_quantizer.config.dtype == weight_dtype.value
+                w_config = child.weight_fake_quantizer.config
+                assert _get_fake_quant_config_dtype(w_config) == weight_dtype.value
                 if group_size:
-                    assert child.weight_fake_quantizer.config.group_size == group_size
+                    assert w_config.group_size == group_size
                 if activation_dtype:
                     assert hasattr(child, "activation_fake_quantizer")
+                    a_config = child.activation_fake_quantizer.config
                     assert (
-                        child.activation_fake_quantizer.config.dtype
-                        == activation_dtype.value
+                        _get_fake_quant_config_dtype(a_config) == activation_dtype.value
                     )
                 else:
                     assert child.activation_fake_quantizer is None
@@ -374,9 +390,16 @@ class TestQuantizationCallback:
 
         # ensure model has been quantized
         assert isinstance(model.model.embed_tokens, FakeQuantizedEmbedding)
-        assert model.model.embed_tokens.weight_fake_quantizer.enabled
         assert isinstance(model.lm_head, FakeQuantizedLinear)
-        assert model.lm_head.weight_fake_quantizer.enabled
+
+        # Only test enable/disable toggling if the fake quantizer supports it
+        # (Int4WeightFakeQuantizer does not have an 'enabled' attribute)
+        supports_toggle = hasattr(
+            model.model.embed_tokens.weight_fake_quantizer, "enabled"
+        )
+        if supports_toggle:
+            assert model.model.embed_tokens.weight_fake_quantizer.enabled
+            assert model.lm_head.weight_fake_quantizer.enabled
 
         qat_callback = QATCallback(cfg)
 
@@ -388,9 +411,10 @@ class TestQuantizationCallback:
             model=model,
         )
 
-        # quantization should have been disabled
-        assert not model.model.embed_tokens.weight_fake_quantizer.enabled
-        assert not model.lm_head.weight_fake_quantizer.enabled
+        if supports_toggle:
+            # quantization should have been disabled
+            assert not model.model.embed_tokens.weight_fake_quantizer.enabled
+            assert not model.lm_head.weight_fake_quantizer.enabled
 
         trainer_state.global_step = 100
         qat_callback.on_step_begin(
@@ -400,9 +424,10 @@ class TestQuantizationCallback:
             model=model,
         )
 
-        # quantization should have been enabled
-        assert model.model.embed_tokens.weight_fake_quantizer.enabled
-        assert model.lm_head.weight_fake_quantizer.enabled
+        if supports_toggle:
+            # quantization should have been enabled
+            assert model.model.embed_tokens.weight_fake_quantizer.enabled
+            assert model.lm_head.weight_fake_quantizer.enabled
 
     @require_torch_2_8_0
     def test_qat_callback_fake_quant_after_n_steps_is_none(self, model, trainer_state):
@@ -424,9 +449,10 @@ class TestQuantizationCallback:
 
         # ensure model has been quantized
         assert isinstance(model.model.embed_tokens, FakeQuantizedEmbedding)
-        assert model.model.embed_tokens.weight_fake_quantizer.enabled
         assert isinstance(model.lm_head, FakeQuantizedLinear)
-        assert model.lm_head.weight_fake_quantizer.enabled
+        if hasattr(model.model.embed_tokens.weight_fake_quantizer, "enabled"):
+            assert model.model.embed_tokens.weight_fake_quantizer.enabled
+            assert model.lm_head.weight_fake_quantizer.enabled
 
         qat_callback = QATCallback(cfg)
         # simulate first training step
@@ -438,5 +464,6 @@ class TestQuantizationCallback:
         )
 
         # quantization should be enabled from the get-go
-        assert model.model.embed_tokens.weight_fake_quantizer.enabled
-        assert model.lm_head.weight_fake_quantizer.enabled
+        if hasattr(model.model.embed_tokens.weight_fake_quantizer, "enabled"):
+            assert model.model.embed_tokens.weight_fake_quantizer.enabled
+            assert model.lm_head.weight_fake_quantizer.enabled

tests/e2e/test_reward_model_smollm2.py

@@ -66,6 +66,6 @@ class TestRewardModelLoraSmolLM2(unittest.TestCase):
 
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_tensorboard(
-            temp_dir + "/runs", "train/train_loss", 2.5, "Train Loss (%s) is too high"
+            temp_dir + "/runs", "train/loss", 2.5, "Train Loss (%s) is too high"
         )
         check_model_output_exists(temp_dir, cfg)

tests/e2e/test_streaming.py

@@ -66,7 +66,7 @@ class TestStreamingDatasets:
         # Verify training actually happened by checking loss decrease
         check_tensorboard(
             temp_dir + "/runs",
-            "train/train_loss",
+            "train/loss",
             3.0,
             "Train Loss (%s) is too high",
         )

tests/patched/test_validation.py

@@ -13,6 +13,7 @@ from axolotl.utils.config import validate_config
 from axolotl.utils.dict import DictDefault
 from axolotl.utils.mlflow_ import setup_mlflow_env_vars
 from axolotl.utils.schemas.config import AxolotlConfigWCapabilities
+from axolotl.utils.schemas.datasets import SFTDataset
 from axolotl.utils.wandb_ import setup_wandb_env_vars
 
 warnings.filterwarnings("error")
@@ -1731,3 +1732,52 @@ class TestDataloaderValidation(BaseValidation):
         assert new_cfg.dataloader_num_workers == 8
         assert new_cfg.dataloader_pin_memory is True
         assert new_cfg.dataloader_prefetch_factor == 256
+
+
+class TestSyntheticDatasetValidation(BaseValidation):
+    """
+    Tests for synthetic dataset config validation
+    """
+
+    @staticmethod
+    def _make_cfg(minimal_cfg, datasets):
+        raw = dict(minimal_cfg)
+        raw["datasets"] = datasets
+        return DictDefault(raw)
+
+    def test_synthetic_dict_config_validates(self, minimal_cfg):
+        """Synthetic dataset passed as a raw dict should not raise."""
+        cfg = self._make_cfg(
+            minimal_cfg,
+            [
+                {
+                    "path": "synthetic",
+                    "type": "_synthetic",
+                    "length": 100,
+                    "sequence_length": 64,
+                }
+            ],
+        )
+
+        new_cfg = validate_config(cfg)
+        assert new_cfg.datasets[0]["path"] == "synthetic"
+
+    def test_synthetic_already_sft_does_not_crash(self, minimal_cfg):
+        """Synthetic dataset already parsed as SFTDataset should not raise AttributeError."""
+        sft = SFTDataset(path="synthetic", type="_synthetic")
+        cfg = self._make_cfg(minimal_cfg, [sft])
+
+        # Before the fix, this raised:
+        #   AttributeError: 'SFTDataset' object has no attribute 'get'
+        new_cfg = validate_config(cfg)
+        assert new_cfg.datasets[0]["path"] == "synthetic"
+
+    def test_non_synthetic_sft_validates(self, minimal_cfg):
+        """A regular SFT dataset should validate without being treated as synthetic."""
+        cfg = self._make_cfg(
+            minimal_cfg,
+            [{"path": "mhenrichsen/alpaca_2k_test", "type": "alpaca"}],
+        )
+
+        new_cfg = validate_config(cfg)
+        assert new_cfg.datasets[0]["path"] == "mhenrichsen/alpaca_2k_test"

tests/prompt_strategies/test_synthetic.py

@@ -0,0 +1,125 @@
+"""Tests for the synthetic dataset generator."""
+
+import unittest
+from unittest.mock import MagicMock
+
+from datasets import Dataset
+
+from axolotl.prompt_strategies._synthetic import SyntheticDatasetStrategy, load
+from axolotl.utils.dict import DictDefault
+
+
+class TestSyntheticDatasetStrategy(unittest.TestCase):
+    def test_generates_correct_shape(self):
+        strategy = SyntheticDatasetStrategy(
+            sequence_length=128,
+            length=50,
+            min_input_id=1,
+            max_input_id=1000,
+            seed=42,
+        )
+        dummy = Dataset.from_dict({"text": [""]})
+        result = strategy.wrap_dataset(dummy)
+
+        assert len(result) == 50
+        assert len(result[0]["input_ids"]) == 128
+        assert len(result[0]["attention_mask"]) == 128
+        assert len(result[0]["labels"]) == 128
+
+    def test_attention_mask_all_ones(self):
+        strategy = SyntheticDatasetStrategy(sequence_length=64, length=10, seed=0)
+        dummy = Dataset.from_dict({"text": [""]})
+        result = strategy.wrap_dataset(dummy)
+
+        for row in result:
+            assert all(v == 1 for v in row["attention_mask"])
+
+    def test_labels_equal_input_ids(self):
+        strategy = SyntheticDatasetStrategy(sequence_length=64, length=10, seed=0)
+        dummy = Dataset.from_dict({"text": [""]})
+        result = strategy.wrap_dataset(dummy)
+
+        for row in result:
+            assert row["input_ids"] == row["labels"]
+
+    def test_input_id_range(self):
+        strategy = SyntheticDatasetStrategy(
+            sequence_length=64,
+            length=100,
+            min_input_id=500,
+            max_input_id=600,
+            seed=42,
+        )
+        dummy = Dataset.from_dict({"text": [""]})
+        result = strategy.wrap_dataset(dummy)
+
+        for row in result:
+            for token_id in row["input_ids"]:
+                assert 500 <= token_id < 600
+
+    def test_seed_reproducibility(self):
+        kwargs = dict(
+            sequence_length=64, length=20, min_input_id=1, max_input_id=1000, seed=123
+        )
+        dummy = Dataset.from_dict({"text": [""]})
+
+        result1 = SyntheticDatasetStrategy(**kwargs).wrap_dataset(dummy)
+        result2 = SyntheticDatasetStrategy(**kwargs).wrap_dataset(dummy)
+
+        for r1, r2 in zip(result1, result2, strict=True):
+            assert r1["input_ids"] == r2["input_ids"]
+
+    def test_different_seeds_differ(self):
+        common = dict(sequence_length=64, length=20, min_input_id=1, max_input_id=1000)
+        dummy = Dataset.from_dict({"text": [""]})
+
+        result1 = SyntheticDatasetStrategy(seed=1, **common).wrap_dataset(dummy)
+        result2 = SyntheticDatasetStrategy(seed=2, **common).wrap_dataset(dummy)
+
+        any_different = any(
+            r1["input_ids"] != r2["input_ids"]
+            for r1, r2 in zip(result1, result2, strict=True)
+        )
+        assert any_different
+
+    def test_load_function_with_ds_cfg(self):
+        tokenizer = MagicMock()
+        tokenizer.vocab_size = 32000
+        cfg = DictDefault({"sequence_len": 512, "train_on_inputs": False})
+        ds_cfg = {
+            "sequence_length": 256,
+            "length": 5,
+            "min_input_id": 10,
+            "max_input_id": 100,
+            "seed": 0,
+        }
+
+        strategy = load(tokenizer, cfg, ds_cfg=ds_cfg)
+        assert isinstance(strategy, SyntheticDatasetStrategy)
+        assert strategy.sequence_length == 256
+        assert strategy.length == 5
+        assert strategy.min_input_id == 10
+        assert strategy.max_input_id == 100
+
+    def test_load_defaults_from_cfg(self):
+        tokenizer = MagicMock()
+        tokenizer.vocab_size = 32000
+        cfg = DictDefault({"sequence_len": 1024, "train_on_inputs": False})
+
+        strategy = load(tokenizer, cfg, ds_cfg={})
+        assert strategy.sequence_length == 1024
+        assert strategy.max_input_id == 32000
+        assert strategy.length == 1000
+
+    def test_load_with_no_ds_cfg(self):
+        tokenizer = MagicMock()
+        tokenizer.vocab_size = 50000
+        cfg = DictDefault({"sequence_len": 2048, "train_on_inputs": False})
+
+        strategy = load(tokenizer, cfg)
+        assert strategy.sequence_length == 2048
+        assert strategy.max_input_id == 50000
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_expand_mask.py

@@ -1,45 +0,0 @@
-"""
-Unit tests for the monkey patch for expand mask to handle packed sequences
-"""
-
-import unittest
-
-import torch
-
-from axolotl.monkeypatch.llama_expand_mask import _expand_mask
-
-
-class TestExpandMask(unittest.TestCase):
-    """
-    Test class for attention mask expansion for packed sequences
-    """
-
-    def test_output(self):
-        mask = torch.tensor([[1, 1, 1, 2], [2, 3, 3, 0]])
-        dtype = torch.float32
-        expected_output = torch.tensor(
-            [
-                [
-                    [
-                        [0.0000e00, -3.4028e38, -3.4028e38, -3.4028e38],
-                        [0.0000e00, 0.0000e00, -3.4028e38, -3.4028e38],
-                        [0.0000e00, 0.0000e00, 0.0000e00, -3.4028e38],
-                        [-3.4028e38, -3.4028e38, -3.4028e38, 0.0000e00],
-                    ]
-                ],
-                [
-                    [
-                        [0.0000e00, -3.4028e38, -3.4028e38, -3.4028e38],
-                        [-3.4028e38, 0.0000e00, -3.4028e38, -3.4028e38],
-                        [-3.4028e38, 0.0000e00, 0.0000e00, -3.4028e38],
-                        [-3.4028e38, -3.4028e38, -3.4028e38, -3.4028e38],
-                    ]
-                ],
-            ]
-        )
-        # Check that the output matches the expected output
-        self.assertTrue(torch.allclose(_expand_mask(mask, dtype), expected_output))
-
-
-if __name__ == "__main__":
-    unittest.main()