1 /* 2 * Copyright 2010, Ingo Weinhold <ingo_weinhold@gmx.de>. 3 * Copyright 2007, Hugo Santos. All Rights Reserved. 4 * Distributed under the terms of the MIT License. 5 */ 6 7 8 #include "slab_private.h" 9 10 #include <stdio.h> 11 #include <string.h> 12 13 #include <algorithm> 14 15 #include <debug.h> 16 #include <heap.h> 17 #include <kernel.h> // for ROUNDUP 18 #include <malloc.h> 19 #include <vm/vm.h> 20 #include <vm/VMAddressSpace.h> 21 22 #include "ObjectCache.h" 23 #include "MemoryManager.h" 24 25 26 #define DEBUG_ALLOCATOR 27 //#define TEST_ALL_CACHES_DURING_BOOT 28 29 static const size_t kBlockSizes[] = { 30 16, 24, 32, 48, 64, 80, 96, 112, 31 128, 160, 192, 224, 256, 320, 384, 448, 32 512, 640, 768, 896, 1024, 1280, 1536, 1792, 33 2048, 2560, 3072, 3584, 4096, 4608, 5120, 5632, 34 6144, 6656, 7168, 7680, 8192, 35 0 36 }; 37 38 static const size_t kNumBlockSizes = sizeof(kBlockSizes) / sizeof(size_t) - 1; 39 40 static object_cache* sBlockCaches[kNumBlockSizes]; 41 42 static addr_t sBootStrapMemory = 0; 43 static size_t sBootStrapMemorySize = 0; 44 static size_t sUsedBootStrapMemory = 0; 45 46 47 RANGE_MARKER_FUNCTION_BEGIN(slab_allocator) 48 49 50 static int 51 size_to_index(size_t size) 52 { 53 if (size <= 16) 54 return 0; 55 if (size <= 32) 56 return 1 + (size - 16 - 1) / 8; 57 if (size <= 128) 58 return 3 + (size - 32 - 1) / 16; 59 if (size <= 256) 60 return 9 + (size - 128 - 1) / 32; 61 if (size <= 512) 62 return 13 + (size - 256 - 1) / 64; 63 if (size <= 1024) 64 return 17 + (size - 512 - 1) / 128; 65 if (size <= 2048) 66 return 21 + (size - 1024 - 1) / 256; 67 if (size <= 8192) 68 return 25 + (size - 2048 - 1) / 512; 69 70 return -1; 71 } 72 73 74 void* 75 block_alloc(size_t size, size_t alignment, uint32 flags) 76 { 77 if (alignment > kMinObjectAlignment) { 78 // Make size >= alignment and a power of two. This is sufficient, since 79 // all of our object caches with power of two sizes are aligned. We may 80 // waste quite a bit of memory, but memalign() is very rarely used 81 // in the kernel and always with power of two size == alignment anyway. 82 ASSERT((alignment & (alignment - 1)) == 0); 83 while (alignment < size) 84 alignment <<= 1; 85 size = alignment; 86 87 // If we're not using an object cache, make sure that the memory 88 // manager knows it has to align the allocation. 89 if (size > kBlockSizes[kNumBlockSizes]) 90 flags |= CACHE_ALIGN_ON_SIZE; 91 } 92 93 // allocate from the respective object cache, if any 94 int index = size_to_index(size); 95 if (index >= 0) 96 return object_cache_alloc(sBlockCaches[index], flags); 97 98 // the allocation is too large for our object caches -- ask the memory 99 // manager 100 void* block; 101 if (MemoryManager::AllocateRaw(size, flags, block) != B_OK) 102 return NULL; 103 104 return block; 105 } 106 107 108 void* 109 block_alloc_early(size_t size) 110 { 111 int index = size_to_index(size); 112 if (index >= 0 && sBlockCaches[index] != NULL) 113 return object_cache_alloc(sBlockCaches[index], CACHE_DURING_BOOT); 114 115 if (size > SLAB_CHUNK_SIZE_SMALL) { 116 // This is a sufficiently large allocation -- just ask the memory 117 // manager directly. 118 void* block; 119 if (MemoryManager::AllocateRaw(size, 0, block) != B_OK) 120 return NULL; 121 122 return block; 123 } 124 125 // A small allocation, but no object cache yet. Use the bootstrap memory. 126 // This allocation must never be freed! 127 if (sBootStrapMemorySize - sUsedBootStrapMemory < size) { 128 // We need more memory. 129 void* block; 130 if (MemoryManager::AllocateRaw(SLAB_CHUNK_SIZE_SMALL, 0, block) != B_OK) 131 return NULL; 132 sBootStrapMemory = (addr_t)block; 133 sBootStrapMemorySize = SLAB_CHUNK_SIZE_SMALL; 134 sUsedBootStrapMemory = 0; 135 } 136 137 size_t neededSize = ROUNDUP(size, sizeof(double)); 138 if (sUsedBootStrapMemory + neededSize > sBootStrapMemorySize) 139 return NULL; 140 void* block = (void*)(sBootStrapMemory + sUsedBootStrapMemory); 141 sUsedBootStrapMemory += neededSize; 142 143 return block; 144 } 145 146 147 void 148 block_free(void* block, uint32 flags) 149 { 150 if (block == NULL) 151 return; 152 153 ObjectCache* cache = MemoryManager::FreeRawOrReturnCache(block, flags); 154 if (cache != NULL) { 155 // a regular small allocation 156 ASSERT(cache->object_size >= kBlockSizes[0]); 157 ASSERT(cache->object_size <= kBlockSizes[kNumBlockSizes - 1]); 158 ASSERT(cache == sBlockCaches[size_to_index(cache->object_size)]); 159 object_cache_free(cache, block, flags); 160 } 161 } 162 163 164 void 165 block_allocator_init_boot() 166 { 167 for (int index = 0; kBlockSizes[index] != 0; index++) { 168 char name[32]; 169 snprintf(name, sizeof(name), "block allocator: %lu", 170 kBlockSizes[index]); 171 172 uint32 flags = CACHE_DURING_BOOT; 173 size_t size = kBlockSizes[index]; 174 175 // align the power of two objects to their size 176 size_t alignment = (size & (size - 1)) == 0 ? size : 0; 177 178 // For the larger allocation sizes disable the object depot, so we don't 179 // keep lot's of unused objects around. 180 if (size > 2048) 181 flags |= CACHE_NO_DEPOT; 182 183 sBlockCaches[index] = create_object_cache_etc(name, size, alignment, 0, 184 0, 0, flags, NULL, NULL, NULL, NULL); 185 if (sBlockCaches[index] == NULL) 186 panic("allocator: failed to init block cache"); 187 } 188 } 189 190 191 void 192 block_allocator_init_rest() 193 { 194 #ifdef TEST_ALL_CACHES_DURING_BOOT 195 for (int index = 0; kBlockSizes[index] != 0; index++) { 196 block_free(block_alloc(kBlockSizes[index] - sizeof(boundary_tag)), 0, 197 0); 198 } 199 #endif 200 } 201 202 203 // #pragma mark - public API 204 205 206 #if USE_SLAB_ALLOCATOR_FOR_MALLOC 207 208 209 void* 210 memalign(size_t alignment, size_t size) 211 { 212 return block_alloc(size, alignment, 0); 213 } 214 215 216 void * 217 memalign_etc(size_t alignment, size_t size, uint32 flags) 218 { 219 return block_alloc(size, alignment, flags & CACHE_ALLOC_FLAGS); 220 } 221 222 223 void 224 free_etc(void *address, uint32 flags) 225 { 226 block_free(address, flags & CACHE_ALLOC_FLAGS); 227 } 228 229 230 void* 231 malloc(size_t size) 232 { 233 return block_alloc(size, 0, 0); 234 } 235 236 237 void 238 free(void* address) 239 { 240 block_free(address, 0); 241 } 242 243 244 void* 245 realloc(void* address, size_t newSize) 246 { 247 if (newSize == 0) { 248 block_free(address, 0); 249 return NULL; 250 } 251 252 if (address == NULL) 253 return block_alloc(newSize, 0, 0); 254 255 size_t oldSize; 256 ObjectCache* cache = MemoryManager::GetAllocationInfo(address, oldSize); 257 if (cache == NULL && oldSize == 0) { 258 panic("block_realloc(): allocation %p not known", address); 259 return NULL; 260 } 261 262 if (oldSize == newSize) 263 return address; 264 265 void* newBlock = block_alloc(newSize, 0, 0); 266 if (newBlock == NULL) 267 return NULL; 268 269 memcpy(newBlock, address, std::min(oldSize, newSize)); 270 271 block_free(address, 0); 272 273 return newBlock; 274 } 275 276 277 #endif // USE_SLAB_ALLOCATOR_FOR_MALLOC 278 279 280 RANGE_MARKER_FUNCTION_END(slab_allocator) 281