Fused DoRA kernels (#216)

* add dora kernels

benchmarks/dora/bench_utils.py

@@ -0,0 +1,131 @@
+import torch
+from bitsandbytes.nn import Linear4bit
+from hqq.core.quantize import BaseQuantizeConfig, HQQLinear
+
+from prototypes.dora.dora_layer import BNBDoRALinear, HQQDoRALinear
+from prototypes.dora.kernels.matmul import triton_mm
+from prototypes.dora.kernels.smallk import triton_mm_small_k
+
+
+def make_lora_weights(ranks, in_features, out_features, dtype):
+    As = [torch.randn(rank, in_features, device="cuda", dtype=dtype) for rank in ranks]
+    Bs = [torch.randn(out_features, rank, device="cuda", dtype=dtype) for rank in ranks]
+    return As, Bs
+
+
+def make_dora_source_and_magnitude(in_features, out_features, dtype):
+    source = torch.randn(out_features, in_features, device="cuda", dtype=dtype)
+    magnitude = torch.randn(out_features, device="cuda", dtype=dtype)
+    return source, magnitude
+
+
+def make_inputs(batch_sizes, seqlen, in_features, dtype):
+    xs = [
+        torch.randn(bs * seqlen, in_features, device="cuda", dtype=dtype)
+        for bs in batch_sizes
+    ]
+    return xs
+
+
+def make_weights(batch_sizes, in_features, out_features, dtype):
+    weights = [
+        torch.randn(in_features, out_features, device="cuda", dtype=dtype)
+        for _ in range(len(batch_sizes))
+    ]
+    return weights
+
+
+def make_epilogue_sources(batch_sizes, seqlen, out_features, dtype):
+    epilogue_sources = [
+        torch.randn(bs * seqlen, out_features, device="cuda", dtype=dtype)
+        for bs in batch_sizes
+    ]
+    return epilogue_sources
+
+
+def make_epilogue_scales(batch_sizes, out_features, dtype):
+    epilogue_scales = [
+        torch.randn(out_features, device="cuda", dtype=dtype)
+        for _ in range(len(batch_sizes))
+    ]
+    return epilogue_scales
+
+
+def dora_colnorm_ref(
+    A: torch.Tensor,
+    B: torch.Tensor,
+    base_weight: torch.Tensor,
+    magnitude_vector: torch.Tensor,
+):
+    column_norm = (base_weight + B @ A).norm(p=2, dim=1)
+    return magnitude_vector / column_norm
+
+
+def dora_mm_epilogue_ref(
+    A: torch.Tensor,
+    B: torch.Tensor,
+    epilogue_source: torch.Tensor,
+    epilogue_scale: torch.Tensor,
+):
+    out = (A @ B + epilogue_source) * epilogue_scale[None, :]
+    return out
+
+
+def dora_ref(x, w, lora_A, lora_B, magnitude_vector):
+    # (bs x seq_len x out_features) = (bs x seq_len x in_features) @ (in_features x rank) @ (rank x out_features)
+    lora_out = (x @ lora_A.T) @ lora_B.T
+    # (out_features)
+    magnitude_scale = dora_colnorm_ref(lora_A, lora_B, w, magnitude_vector)
+    # (bs x seq_len x out_features)
+    dora_out_ref = dora_mm_epilogue_ref(x, w, lora_out, magnitude_scale)
+    return dora_out_ref
+
+
+def dora_triton(x, w, lora_A, lora_B, magnitude_vector):
+    lora_out = (x @ lora_A.T) @ lora_B.T
+    magnitude_scale = triton_mm_small_k(
+        lora_B,
+        lora_A,
+        epilogue_norm=True,
+        source=w,
+        magnitude=magnitude_vector,
+        store_acc=False,
+    )
+    dora_out = triton_mm(x, w, epilogue_source=lora_out, epilogue_scale=magnitude_scale)
+    return dora_out
+
+
+def setup_dora_base_layers(layer_type, in_features, out_features, dtype):
+    if "bnb" in layer_type:
+        # BitsandBytes
+        base_layer = Linear4bit(
+            input_features=in_features,
+            output_features=out_features,
+            bias=False,
+            quant_type="nf4",
+            compute_dtype=dtype,
+        ).cuda()
+        base_layer.quant_state.dtype = base_layer.compute_dtype
+        dora_cls = BNBDoRALinear
+    elif "hqq" in layer_type:
+        # HQQ
+        quant_config = BaseQuantizeConfig(
+            nbits=4,
+            group_size=64,
+            quant_zero=False,
+            quant_scale=False,
+            offload_meta=True,
+            view_as_float=True,
+        )
+        linear = torch.nn.Linear(
+            in_features, out_features, dtype=dtype, bias=False
+        ).cuda()
+        base_layer = HQQLinear(
+            linear,
+            quant_config,
+            compute_dtype=dtype,
+        )
+        dora_cls = HQQDoRALinear
+    else:
+        raise ValueError(f"Unknown layer type: {layer_type}")
+    return base_layer, dora_cls