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fix cross entropy loss issue for small vocab size on amd gpu #3503

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Merged
merged 1 commit into from
Oct 27, 2025
Merged

fix cross entropy loss issue for small vocab size on amd gpu #3503

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1 change: 1 addition & 0 deletions unsloth/kernels/cross_entropy_loss.py
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Expand Up @@ -300,6 +300,7 @@ def forward(ctx, logits, labels, logit_softcapping : float = 0, logit_scaling :
if n_chunks == 1:
# For small vocabs <= 65336 like Llama, Mistral
BLOCK_SIZE, num_warps = calculate_settings(vocab_size)
if is_cdna(): num_warps = num_warps // 2
logsumexp = torch.empty(n_rows, dtype = torch.float32, device = device)

with torch_gpu_device(device):
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7 changes: 1 addition & 6 deletions unsloth/models/mistral.py
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Expand Up @@ -298,12 +298,7 @@ def MistralForCausalLM_fast_forward(
else:
RETURN_LOGITS = os.environ.get("UNSLOTH_RETURN_LOGITS", "0") == "1"
# < 1024 Normal Unsloth uses less VRAM!
if DEVICE_TYPE == "hip":
# [TODO] AMD GPUs fail on chunked_cross_entropy loss!
# RuntimeError: Triton Error [HIP]: Code: 1, Messsage: invalid argument
RETURN_LOGITS = False
elif bsz*q_len <= 1024:
RETURN_LOGITS = True
if bsz * q_len <= 1024: RETURN_LOGITS = True

if not RETURN_LOGITS and labels is not None:
n_items = kwargs.get("num_items_in_batch", None) or kwargs.get("n_items", None)
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