[infer] add autotune for gptq kernel

colossalai/kernel/triton/custom_autotune.py

@@ -0,0 +1,176 @@
+# code from AutoGPTQ auto_gptq: https://github.com/PanQiWei/AutoGPTQ/blob/main/auto_gptq/nn_modules/triton_utils/custom_autotune.py
+
+import builtins
+import math
+import time
+from typing import Dict
+
+import triton
+
+
+class CustomizedTritonAutoTuner(triton.KernelInterface):
+    def __init__(
+        self,
+        fn,
+        arg_names,
+        configs,
+        key,
+        reset_to_zero,
+        prune_configs_by: Dict = None,
+        nearest_power_of_two: bool = False,
+    ):
+        if not configs:
+            self.configs = [triton.Config({}, num_warps=4, num_stages=2)]
+        else:
+            self.configs = configs
+        self.key_idx = [arg_names.index(k) for k in key]
+        self.nearest_power_of_two = nearest_power_of_two
+        self.cache = {}
+        # hook to reset all required tensor to zeros before relaunching a kernel
+        self.hook = lambda args: 0
+        if reset_to_zero is not None:
+            self.reset_idx = [arg_names.index(k) for k in reset_to_zero]
+
+            def _hook(args):
+                for i in self.reset_idx:
+                    args[i].zero_()
+
+            self.hook = _hook
+        self.arg_names = arg_names
+        # prune configs
+        if prune_configs_by:
+            perf_model, top_k = prune_configs_by["perf_model"], prune_configs_by["top_k"]
+            if "early_config_prune" in prune_configs_by:
+                early_config_prune = prune_configs_by["early_config_prune"]
+        else:
+            perf_model, top_k, early_config_prune = None, None, None
+        self.perf_model, self.configs_top_k = perf_model, top_k
+        self.early_config_prune = early_config_prune
+        self.fn = fn
+
+    def _bench(self, *args, config, **meta):
+        # check for conflicts, i.e. meta-parameters both provided
+        # as kwargs and by the autotuner
+        conflicts = meta.keys() & config.kwargs.keys()
+        if conflicts:
+            raise ValueError(
+                f"Conflicting meta-parameters: {', '.join(conflicts)}."
+                " Make sure that you don't re-define auto-tuned symbols."
+            )
+        # augment meta-parameters with tunable ones
+        current = dict(meta, **config.kwargs)
+
+        def kernel_call():
+            if config.pre_hook:
+                config.pre_hook(self.nargs)
+            self.hook(args)
+            self.fn.run(*args, num_warps=config.num_warps, num_stages=config.num_stages, **current)
+
+        try:
+            # In testings using only 40 reps seems to be close enough and it appears to be what PyTorch uses
+            # PyTorch also sets fast_flush to True, but I didn't see any speedup so I'll leave the default
+            return triton.testing.do_bench(kernel_call, percentiles=(0.5, 0.2, 0.8), rep=40)
+        except triton.compiler.OutOfResources:
+            return (float("inf"), float("inf"), float("inf"))
+
+    def run(self, *args, **kwargs):
+        self.nargs = dict(zip(self.arg_names, args))
+        if len(self.configs) > 1:
+            key = tuple(args[i] for i in self.key_idx)
+
+            # This reduces the amount of autotuning by rounding the keys to the nearest power of two
+            # In my testing this gives decent results, and greatly reduces the amount of tuning required
+            if self.nearest_power_of_two:
+                key = tuple([2 ** int(math.log2(x) + 0.5) for x in key])
+
+            if key not in self.cache:
+                # prune configs
+                pruned_configs = self.prune_configs(kwargs)
+                bench_start = time.time()
+                timings = {config: self._bench(*args, config=config, **kwargs) for config in pruned_configs}
+                bench_end = time.time()
+                self.bench_time = bench_end - bench_start
+                self.cache[key] = builtins.min(timings, key=timings.get)
+                self.hook(args)
+                self.configs_timings = timings
+            config = self.cache[key]
+        else:
+            config = self.configs[0]
+        self.best_config = config
+        if config.pre_hook is not None:
+            config.pre_hook(self.nargs)
+        return self.fn.run(*args, num_warps=config.num_warps, num_stages=config.num_stages, **kwargs, **config.kwargs)
+
+    def prune_configs(self, kwargs):
+        pruned_configs = self.configs
+        if self.early_config_prune:
+            pruned_configs = self.early_config_prune(self.configs, self.nargs)
+        if self.perf_model:
+            top_k = self.configs_top_k
+            if isinstance(top_k, float) and top_k <= 1.0:
+                top_k = int(len(self.configs) * top_k)
+            if len(pruned_configs) > top_k:
+                est_timing = {
+                    config: self.perf_model(
+                        **self.nargs,
+                        **kwargs,
+                        **config.kwargs,
+                        num_stages=config.num_stages,
+                        num_warps=config.num_warps,
+                    )
+                    for config in pruned_configs
+                }
+                pruned_configs = sorted(est_timing.keys(), key=lambda x: est_timing[x])[:top_k]
+        return pruned_configs
+
+    def warmup(self, *args, **kwargs):
+        self.nargs = dict(zip(self.arg_names, args))
+        for config in self.prune_configs(kwargs):
+            self.fn.warmup(
+                *args,
+                num_warps=config.num_warps,
+                num_stages=config.num_stages,
+                **kwargs,
+                **config.kwargs,
+            )
+        self.nargs = None
+
+
+def autotune(configs, key, prune_configs_by=None, reset_to_zero=None, nearest_power_of_two=False):
+    def decorator(fn):
+        return CustomizedTritonAutoTuner(
+            fn, fn.arg_names, configs, key, reset_to_zero, prune_configs_by, nearest_power_of_two
+        )
+
+    return decorator
+
+
+def matmul248_kernel_config_pruner(configs, nargs):
+    """
+    The main purpose of this function is to shrink BLOCK_SIZE_* when the corresponding dimension is smaller.
+    """
+    m = max(2 ** int(math.ceil(math.log2(nargs["M"]))), 16)
+    n = max(2 ** int(math.ceil(math.log2(nargs["N"]))), 16)
+    k = max(2 ** int(math.ceil(math.log2(nargs["K"]))), 16)
+
+    used = set()
+    for config in configs:
+        block_size_m = min(m, config.kwargs["BLOCK_SIZE_M"])
+        block_size_n = min(n, config.kwargs["BLOCK_SIZE_N"])
+        block_size_k = min(k, config.kwargs["BLOCK_SIZE_K"])
+        group_size_m = config.kwargs["GROUP_SIZE_M"]
+
+        if (block_size_m, block_size_n, block_size_k, group_size_m, config.num_stages, config.num_warps) in used:
+            continue
+
+        used.add((block_size_m, block_size_n, block_size_k, group_size_m, config.num_stages, config.num_warps))
+        yield triton.Config(
+            {
+                "BLOCK_SIZE_M": block_size_m,
+                "BLOCK_SIZE_N": block_size_n,
+                "BLOCK_SIZE_K": block_size_k,
+                "GROUP_SIZE_M": group_size_m,
+            },
+            num_stages=config.num_stages,
+            num_warps=config.num_warps,
+        )

colossalai/kernel/triton/gptq_triton.py

@@ -3,7 +3,8 @@
 import torch
 import triton
 import triton.language as tl
-from auto_gptq.nn_modules.triton_utils import custom_autotune
+
+from .custom_autotune import autotune, matmul248_kernel_config_pruner
 
 
 @triton.jit
@@ -94,7 +95,7 @@ def silu(x):
     return x * tl.sigmoid(x)
 
 
-@custom_autotune.autotune(
+@autotune(
     configs=[
         triton.Config(
             {"BLOCK_SIZE_M": 64, "BLOCK_SIZE_N": 256, "BLOCK_SIZE_K": 32, "GROUP_SIZE_M": 8}, num_stages=4, num_warps=4
@@ -124,7 +125,7 @@ def silu(x):
     key=["M", "N", "K"],
     nearest_power_of_two=True,
     prune_configs_by={
-        "early_config_prune": custom_autotune.matmul248_kernel_config_pruner,
+        "early_config_prune": matmul248_kernel_config_pruner,
         "perf_model": None,
         "top_k": None,
     },
@@ -266,7 +267,7 @@ def cai_gptq_matmul_248_kernel(
     tl.store(c_ptrs, accumulator, mask=c_mask)
 
 
-@custom_autotune.autotune(
+@autotune(
     configs=[
         triton.Config(
             {"BLOCK_SIZE_M": 64, "BLOCK_SIZE_N": 256, "BLOCK_SIZE_K": 32, "GROUP_SIZE_M": 8}, num_stages=4, num_warps=4
@@ -296,7 +297,7 @@ def cai_gptq_matmul_248_kernel(
     key=["M", "N", "K"],
     nearest_power_of_two=True,
     prune_configs_by={
-        "early_config_prune": custom_autotune.matmul248_kernel_config_pruner,
+        "early_config_prune": matmul248_kernel_config_pruner,
         "perf_model": None,
         "top_k": None,
     },