Improve cuBLAS performance by using a memory pool (#1094)

slaren · web-flow · commit 50cb666b8a2e · 2023-04-21T21:59:17.000+02:00
* Improve cuBLAS performance by using a memory pool

* Move cuda specific definitions to ggml-cuda.h/cu

* Add CXX flags to nvcc

* Change memory pool synchronization mechanism to a spin lock
General code cleanup
diff --git a/Makefile b/Makefile
@@ -101,11 +101,13 @@ ifdef LLAMA_OPENBLAS
 	LDFLAGS += -lopenblas
 endif
 ifdef LLAMA_CUBLAS
-	CFLAGS  += -DGGML_USE_CUBLAS -I/usr/local/cuda/include
-	LDFLAGS += -lcublas -lculibos -lcudart -lcublasLt -lpthread -ldl -lrt -L/usr/local/cuda/lib64
-	OBJS	+= ggml-cuda.o
+	CFLAGS    += -DGGML_USE_CUBLAS -I/usr/local/cuda/include
+	LDFLAGS   += -lcublas -lculibos -lcudart -lcublasLt -lpthread -ldl -lrt -L/usr/local/cuda/lib64
+	OBJS      += ggml-cuda.o
+	NVCC      = nvcc
+	NVCCFLAGS = --forward-unknown-to-host-linker -arch=native
 ggml-cuda.o: ggml-cuda.cu ggml-cuda.h
-	nvcc -arch=native -c -o $@ $<
+	$(NVCC) $(NVCCFLAGS) $(CXXFLAGS) -c $< -o $@
 endif
 ifdef LLAMA_GPROF
 	CFLAGS   += -pg
diff --git a/ggml-cuda.cu b/ggml-cuda.cu
@@ -1,5 +1,7 @@
 #include <stdint.h>
+#include <stdio.h>
 #include <cuda_fp16.h>
+#include <atomic>
 #include "ggml-cuda.h"
 
 typedef uint16_t ggml_fp16_t;
@@ -29,14 +31,12 @@ static_assert(sizeof(block_q4_2) == sizeof(ggml_fp16_t) + QK4_2 / 2, "wrong q4_2
 
 #define QK4_3 16
 typedef struct {
-    __half  d;         // delta
-    __half  m;         // min
-    uint8_t qs[QK4_3 / 2]; // nibbles / quants
+    __half  d;              // delta
+    __half  m;              // min
+    uint8_t qs[QK4_3 / 2];  // nibbles / quants
 } block_q4_3;
 static_assert(sizeof(block_q4_3) == 2 * sizeof(ggml_fp16_t) + QK4_3 / 2, "wrong q4_3 block size/padding");
 
-
-
 static __global__ void dequantize_block_q4_0(const void * vx, float * y) {
     const block_q4_0 * x = (const block_q4_0 *) vx;
 
@@ -131,24 +131,98 @@ static __global__ void dequantize_block_q4_3(const void * vx, float * y) {
     }
 }
 
-extern "C" {
-    __host__ void dequantize_row_q4_0_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
-        const int nb = k / QK4_0;
-        dequantize_block_q4_0<<<nb, 1, 0, stream>>>(vx, y);
-    }
+void dequantize_row_q4_0_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
+    const int nb = k / QK4_0;
+    dequantize_block_q4_0<<<nb, 1, 0, stream>>>(vx, y);
+}
+
+void dequantize_row_q4_1_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
+    const int nb = k / QK4_1;
+    dequantize_block_q4_1<<<nb, 1, 0, stream>>>(vx, y);
+}
+
+void dequantize_row_q4_2_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
+    const int nb = k / QK4_2;
+    dequantize_block_q4_2<<<nb, 1, 0, stream>>>(vx, y);
+}
+
+void dequantize_row_q4_3_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
+    const int nb = k / QK4_3;
+    dequantize_block_q4_3<<<nb, 1, 0, stream>>>(vx, y);
+}
 
-    __host__ void dequantize_row_q4_1_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
-        const int nb = k / QK4_1;
-        dequantize_block_q4_1<<<nb, 1, 0, stream>>>(vx, y);
+// buffer pool for cuda
+#define MAX_CUDA_BUFFERS 16
+
+struct scoped_spin_lock {
+    std::atomic_flag& lock;
+    scoped_spin_lock(std::atomic_flag& lock) : lock(lock) {
+        while (lock.test_and_set(std::memory_order_acquire)) {
+            ; // spin
+        }
+    }
+    ~scoped_spin_lock() {
+        lock.clear(std::memory_order_release);
+    }
+    scoped_spin_lock(const scoped_spin_lock&) = delete;
+    scoped_spin_lock& operator=(const scoped_spin_lock&) = delete;
+};
+
+struct cuda_buffer {
+    void * ptr = nullptr;
+    size_t size = 0;
+};
+
+static cuda_buffer g_cuda_buffer_pool[MAX_CUDA_BUFFERS];
+static std::atomic_flag g_cuda_pool_lock = ATOMIC_FLAG_INIT;
+
+void * ggml_cuda_pool_malloc(size_t size, size_t * actual_size) {
+    scoped_spin_lock lock(g_cuda_pool_lock);
+
+    for (int i = 0; i < MAX_CUDA_BUFFERS; ++i) {
+        cuda_buffer& b = g_cuda_buffer_pool[i];
+        if (b.size >= size && b.ptr != nullptr) {
+            void * ptr = b.ptr;
+            *actual_size = b.size;
+            b.ptr = nullptr;
+            b.size = 0;
+            return ptr;
+        }
     }
+    void * ptr;
+    CUDA_CHECK(cudaMalloc((void **) &ptr, size));
+    *actual_size = size;
+    return ptr;
+}
+
+void ggml_cuda_pool_free(void * ptr, size_t size) {
+    scoped_spin_lock lock(g_cuda_pool_lock);
 
-    __host__ void dequantize_row_q4_2_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
-        const int nb = k / QK4_2;
-        dequantize_block_q4_2<<<nb, 1, 0, stream>>>(vx, y);
+    for (int i = 0; i < MAX_CUDA_BUFFERS; ++i) {
+        cuda_buffer& b = g_cuda_buffer_pool[i];
+        if (b.ptr == nullptr) {
+            b.ptr = ptr;
+            b.size = size;
+            return;
+        }
     }
+    fprintf(stderr, "WARNING: cuda buffer pool full, increase MAX_CUDA_BUFFERS\n");
+    CUDA_CHECK(cudaFree(ptr));
+}
+
+cublasHandle_t g_cublasH = NULL;
+cudaStream_t g_cudaStream = NULL;
+
+void ggml_init_cublas(void) {
+    if (g_cublasH == NULL) {
+        // create cublas handle, bind a stream
+        CUBLAS_CHECK(cublasCreate(&g_cublasH));
+
+        CUDA_CHECK(cudaStreamCreateWithFlags(&g_cudaStream, cudaStreamNonBlocking));
+
+        CUBLAS_CHECK(cublasSetStream(g_cublasH, g_cudaStream));
 
-    __host__ void dequantize_row_q4_3_cuda(const void * vx, float * y, int k, cudaStream_t stream) {
-        const int nb = k / QK4_3;
-        dequantize_block_q4_3<<<nb, 1, 0, stream>>>(vx, y);
+        // configure logging to stdout
+        // CUBLAS_CHECK(cublasLoggerConfigure(1, 1, 0, NULL));
     }
 }
diff --git a/ggml-cuda.h b/ggml-cuda.h
@@ -1,7 +1,36 @@
+#include <cublas_v2.h>
+#include <cuda_runtime.h>
+
 #ifdef  __cplusplus
 extern "C" {
 #endif
 
+#define CUDA_CHECK(err)                                                                 \
+    do {                                                                                \
+        cudaError_t err_ = (err);                                                       \
+        if (err_ != cudaSuccess) {                                                      \
+            fprintf(stderr, "CUDA error %d at %s:%d: %s\n", err_, __FILE__, __LINE__,   \
+                cudaGetErrorString(err_));                                              \
+            exit(1);                                                                    \
+        }                                                                               \
+    } while (0)
+
+#define CUBLAS_CHECK(err)                                                               \
+    do {                                                                                \
+        cublasStatus_t err_ = (err);                                                    \
+        if (err_ != CUBLAS_STATUS_SUCCESS) {                                            \
+            fprintf(stderr, "cuBLAS error %d at %s:%d\n", err_, __FILE__, __LINE__);    \
+            exit(1);                                                                    \
+        }                                                                               \
+    } while (0)
+
+extern cublasHandle_t g_cublasH;
+extern cudaStream_t   g_cudaStream;
+
+void   ggml_init_cublas(void);
+void * ggml_cuda_pool_malloc(size_t size, size_t * actual_size);
+void   ggml_cuda_pool_free(void * ptr, size_t size);
+
 void dequantize_row_q4_0_cuda(const void * vx, float * y, int k, cudaStream_t stream);
 void dequantize_row_q4_1_cuda(const void * vx, float * y, int k, cudaStream_t stream);
 void dequantize_row_q4_2_cuda(const void * vx, float * y, int k, cudaStream_t stream);
diff --git a/ggml.c b/ggml.c
