Fixed OpenLLaMA 3b CUDA mul_mat_vec_q (#2144)

Author: JohannesGaessler

ggml-cuda.cu

@@ -208,6 +208,7 @@ typedef struct {
 static_assert(sizeof(block_q6_K) == sizeof(ggml_fp16_t) + 13*QK_K/16, "wrong q6_K block size/padding");
 
 #define WARP_SIZE 32
+#define MATRIX_ROW_PADDING 256 // last row of quant. matrices is a multiple of this to avoid out-of-bounds memory accesses
 
 #define CUDA_ADD_BLOCK_SIZE 256
 #define CUDA_MUL_BLOCK_SIZE 256
@@ -1171,7 +1172,7 @@ static __device__ void convert_f16(const void * vx, const int ib, const int iqs,
     v.y = x[ib + iqs + 1];
 }
 
-static __global__ void quantize_q8_1(const float * __restrict__ x, void * __restrict__ vy, const int k) {
+static __global__ void quantize_q8_1(const float * __restrict__ x, void * __restrict__ vy, const int ndata, const int k) {
     const int i = blockDim.x*blockIdx.x + threadIdx.x;
 
     if (i >= k) {
@@ -1180,10 +1181,10 @@ static __global__ void quantize_q8_1(const float * __restrict__ x, void * __rest
 
     block_q8_1 * y = (block_q8_1 *) vy;
 
-    const int ib = i / QK8_0; // block index
-    const int iqs = i % QK8_0; // quant index
+    const int ib = i / QK8_1; // block index
+    const int iqs = i % QK8_1; // quant index
 
-    const float xi = x[i];
+    const float xi = i < ndata ? x[i] : 0.0f;
     float amax = fabsf(xi);
     float sum = xi;
 
@@ -1714,9 +1715,9 @@ static void rms_norm_f32_cuda(const float * x, float * dst, const int ncols, con
     rms_norm_f32<<<nrows, block_dims, 0, stream>>>(x, dst, ncols);
 }
 
-static void quantize_row_q8_1_cuda(const float * x, void * vy, const int k, cudaStream_t stream) {
+static void quantize_row_q8_1_cuda(const float * x, void * vy, const int ndata, const int k, cudaStream_t stream) {
     const int num_blocks = (k + CUDA_QUANTIZE_BLOCK_SIZE - 1) / CUDA_QUANTIZE_BLOCK_SIZE;
-    quantize_q8_1<<<num_blocks, CUDA_QUANTIZE_BLOCK_SIZE, 0, stream>>>(x, vy, k);
+    quantize_q8_1<<<num_blocks, CUDA_QUANTIZE_BLOCK_SIZE, 0, stream>>>(x, vy, ndata, k);
 }
 
 static void dequantize_row_q4_0_cuda(const void * vx, float * y, const int k, cudaStream_t stream) {
@@ -2359,9 +2360,11 @@ inline void ggml_cuda_op_mul_mat_vec(
 #endif
 
     if (use_mul_mat_vec_q) {
+        int64_t padded_row_size = ne00 + MATRIX_ROW_PADDING - 1;
+        padded_row_size -= padded_row_size % MATRIX_ROW_PADDING;
         size_t as;
-        void * src1_q8_1 = ggml_cuda_pool_malloc(ne00*sizeof(block_q8_1)/QK8_1, &as);
-        quantize_row_q8_1_cuda(src1_ddf_i, src1_q8_1, ne00, cudaStream_main);
+        void * src1_q8_1 = ggml_cuda_pool_malloc(padded_row_size*sizeof(block_q8_1)/QK8_1, &as);
+        quantize_row_q8_1_cuda(src1_ddf_i, src1_q8_1, ne00, padded_row_size, cudaStream_main);
 
         switch (src0->type) {
             case GGML_TYPE_Q4_0:
@@ -3105,7 +3108,11 @@ void ggml_cuda_nop(const ggml_tensor * src0, const ggml_tensor * src1, ggml_tens
 
 void ggml_cuda_transform_tensor(void * data, struct ggml_tensor * tensor) {
     int nrows = ggml_nrows(tensor);
+
+    const int64_t ne0 = tensor->ne[0];
+
     const size_t nb1 = tensor->nb[1];
+
     ggml_backend backend = tensor->backend;
     struct ggml_tensor_extra_gpu * extra = new struct ggml_tensor_extra_gpu;
     memset(extra, 0, sizeof(*extra));
@@ -3134,11 +3141,24 @@ void ggml_cuda_transform_tensor(void * data, struct ggml_tensor * tensor) {
         int64_t nrows_split = row_high - row_low;
 
         const size_t offset_split = row_low*nb1;
-        const size_t size = ggml_nbytes_split(tensor, nrows_split);
+        size_t size = ggml_nbytes_split(tensor, nrows_split);
+        const size_t original_size = size;
+
+        // pad last row to a multiple of 256 elements to avoid out-of-bounds memory accesses
+        if (ne0 % MATRIX_ROW_PADDING != 0) {
+            size += (MATRIX_ROW_PADDING - ne0 % MATRIX_ROW_PADDING)
+                * ggml_type_size(tensor->type)/ggml_blck_size(tensor->type);
+        }
 
-        void * buf;
+        char * buf;
         CUDA_CHECK(cudaMalloc(&buf, size));
-        void * buf_host = (char*)data + offset_split;
+        char * buf_host = (char*)data + offset_split;
+
+        // set padding to 0 to avoid possible NaN values
+        if (size > original_size) {
+            CUDA_CHECK(cudaMemset(buf + original_size, 0, size - original_size));
+        }
+
 
         cudaMemcpy(buf, buf_host, size, cudaMemcpyHostToDevice);