Index: tools/GPURuntime/GPUJIT.h =================================================================== --- tools/GPURuntime/GPUJIT.h +++ tools/GPURuntime/GPUJIT.h @@ -13,6 +13,7 @@ #ifndef GPUJIT_H_ #define GPUJIT_H_ +#include "stddef.h" /* * The following demostrates how we can use the GPURuntime library to @@ -110,4 +111,13 @@ void **Parameters); void polly_freeDeviceMemory(PollyGPUDevicePtr *Allocation); void polly_freeContext(PollyGPUContext *Context); + +// Note that polly_{malloc/free}Managed are currently not used by Polly. +// We use them in COSMO by replacing all malloc with polly_mallocManaged and all +// frees with cudaFree, so we can get managed memory "automatically". +// Needless to say, this is a hack. +// Please make sure that this code is not present in Polly when 2018 rolls in. +// If this is still present, ping Siddharth Bhat +void *polly_mallocManaged(size_t size); +void polly_freeManaged(void *mem); #endif /* GPUJIT_H_ */ Index: tools/GPURuntime/GPUJIT.c =================================================================== --- tools/GPURuntime/GPUJIT.c +++ tools/GPURuntime/GPUJIT.c @@ -1409,6 +1409,61 @@ } } +// Maximum number of managed memory pointers. +#define MAX_POINTERS 4000 +// For the rationale behing a list of free pointers, see `polly_freeManaged`. +void *g_managedptrs[MAX_POINTERS]; +int g_nmanagedptrs = 0; + +// Add a pointer as being allocated by cuMallocManaged +void addManagedPtr(void *mem) { + assert(g_nmanagedptrs < MAX_POINTERS && "We have hit the maximum number of " + "managed pointers allowed. Increase " + "MAX_POINTERS"); + g_managedptrs[g_nmanagedptrs++] = mem; +} + +int isManagedPtr(void *mem) { + for (int i = 0; i < g_nmanagedptrs; i++) { + if (g_managedptrs[i] == mem) + return 1; + } + return 0; +} + +void polly_freeManaged(void *mem) { + dump_function(); + + // In a real-world program this was used (COSMO), there were more `free` + // calls in the original source than `malloc` calls. Hence, replacing all + // `free`s with `cudaFree` does not work, since we would try to free + // 'illegal' memory. + // As a quick fix, we keep a free list and check if `mem` is a managed memory + // pointer. If it is, we call `cudaFree`. + // If not, we pass it along to the underlying allocator. + // This is a hack, and can be removed if the underlying issue is fixed. + if (isManagedPtr(mem)) { + if (cudaFree(mem) != cudaSuccess) { + fprintf(stderr, "cudaFree failed.\n"); + exit(-1); + } + return; + } else { + free(mem); + } +} + +void *polly_mallocManaged(size_t size) { + dump_function(); + void *a; + if (cudaMallocManaged(&a, size, cudaMemAttachGlobal) != cudaSuccess) { + fprintf(stderr, "cudaMallocManaged failed for size: %zu\n", size); + exit(-1); + } + addManagedPtr(a); + return a; +} + static void freeDeviceMemoryCUDA(PollyGPUDevicePtr *Allocation) { dump_function(); CUDADevicePtr *DevPtr = (CUDADevicePtr *)Allocation->DevicePtr;