osfmk/vm/vm_compressor_algorithms.c

   1 /*
   2  * Copyright (c) 2010-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* This module implements a hybrid/adaptive compression scheme, using WKdm where
  29  * profitable and, currently, an LZ4 variant elsewhere.
  30  * (Created 2016, Derek Kumar)
  31  */
  32 #include "lz4.h"
  33 #include "WKdm_new.h"
  34 #include <vm/vm_compressor_algorithms.h>
  35 #include <vm/vm_compressor.h>
  36
  37 #define MZV_MAGIC (17185)
  38 #if defined(__arm64__)
  39 #include <arm/proc_reg.h>
  40 #endif
  41
  42 #define LZ4_SCRATCH_ALIGN (64)
  43 #define WKC_SCRATCH_ALIGN (64)
  44
  45 #define LZ4_SCRATCH_ALIGN (64)
  46 #define WKC_SCRATCH_ALIGN (64)
  47
  48 #define memcpy_T_NT memcpy
  49 #define memcpy_NT_T memcpy
  50
  51 typedef union {
  52         uint8_t lz4state[lz4_encode_scratch_size]__attribute((aligned(LZ4_SCRATCH_ALIGN)));
  53         uint8_t wkscratch[0] __attribute((aligned(WKC_SCRATCH_ALIGN))); // TODO
  54 } compressor_encode_scratch_t;
  55
  56 typedef union {
  57         uint8_t lz4decodestate[lz4_encode_scratch_size]__attribute((aligned(64)));
  58         uint8_t wkdecompscratch[0] __attribute((aligned(64)));
  59 } compressor_decode_scratch_t;
  60
  61 typedef struct {
  62         uint16_t lz4_selection_run;
  63         uint16_t lz4_run_length;
  64         uint16_t lz4_preselects;
  65         uint32_t lz4_total_preselects;
  66         uint16_t lz4_failure_skips;
  67         uint32_t lz4_total_failure_skips;
  68         uint16_t lz4_failure_run_length;
  69         uint16_t lz4_total_unprofitables;
  70         uint32_t lz4_total_negatives;
  71         uint32_t lz4_total_failures;
  72 } compressor_state_t;
  73
  74 compressor_tuneables_t vmctune = {
  75         .lz4_threshold = 2048,
  76         .wkdm_reeval_threshold = 1536,
  77         .lz4_max_failure_skips = 0,
  78         .lz4_max_failure_run_length = ~0U,
  79         .lz4_max_preselects = 0,
  80         .lz4_run_preselection_threshold = ~0U,
  81         .lz4_run_continue_bytes = 0,
  82         .lz4_profitable_bytes = 0,
  83 };
  84
  85 compressor_state_t vmcstate = {
  86         .lz4_selection_run = 0,
  87         .lz4_run_length = 0,
  88         .lz4_preselects = 0,
  89         .lz4_total_preselects = 0,
  90         .lz4_failure_skips = 0,
  91         .lz4_total_failure_skips = 0,
  92         .lz4_failure_run_length = 0,
  93         .lz4_total_unprofitables = 0,
  94         .lz4_total_negatives = 0,
  95 };
  96
  97 compressor_stats_t compressor_stats;
  98
  99 enum compressor_preselect_t {
 100         CPRESELLZ4 = 0,
 101         CSKIPLZ4 = 1,
 102         CPRESELWK = 2,
 103 };
 104
 105 vm_compressor_mode_t vm_compressor_current_codec = VM_COMPRESSOR_DEFAULT_CODEC;
 106
 107 boolean_t vm_compressor_force_sw_wkdm = FALSE;
 108
 109 boolean_t verbose = FALSE;
 110
 111 #define VMDBGSTAT (DEBUG)
 112 #if VMDBGSTATS
 113 #define VM_COMPRESSOR_STAT_DBG(x...)                                    \
 114         do {                                                            \
 115                 (x);                                                    \
 116         } while(0)
 117 #else
 118 #define VM_COMPRESSOR_STAT_DBG(x...)                                    \
 119         do {                                                            \
 120         } while (0)
 121 #endif
 122
 123 #define VMCSTATS (DEVELOPMENT || DEBUG)
 124 #if VMCSTATS
 125 #define VM_COMPRESSOR_STAT(x...)                                        \
 126         do {                                                            \
 127                 (x);                                                    \
 128         } while(0)
 129 //TODO make atomic where needed, decompression paths
 130 #define VM_DECOMPRESSOR_STAT(x...)                                      \
 131         do {                                                            \
 132                 (x);                                                    \
 133         } while(0)
 134 #else
 135 #define VM_COMPRESSOR_STAT(x...)                                        \
 136         do {                                                            \
 137         }while (0)
 138 #define VM_DECOMPRESSOR_STAT(x...)                                      \
 139         do {                                                            \
 140         }while (0)
 141 #endif
 142
 143 static inline enum compressor_preselect_t compressor_preselect(void) {
 144         if (vmcstate.lz4_failure_skips >= vmctune.lz4_max_failure_skips) {
 145                 vmcstate.lz4_failure_skips = 0;
 146                 vmcstate.lz4_failure_run_length = 0;
 147         }
 148
 149         if (vmcstate.lz4_failure_run_length >= vmctune.lz4_max_failure_run_length) {
 150                 vmcstate.lz4_failure_skips++;
 151                 vmcstate.lz4_total_failure_skips++;
 152                 return CSKIPLZ4;
 153         }
 154
 155         if (vmcstate.lz4_preselects >= vmctune.lz4_max_preselects) {
 156                 vmcstate.lz4_preselects = 0;
 157                 return CPRESELWK;
 158         }
 159
 160         if (vmcstate.lz4_run_length >= vmctune.lz4_run_preselection_threshold) {
 161                 vmcstate.lz4_preselects++;
 162                 vmcstate.lz4_total_preselects++;
 163                 return CPRESELLZ4;
 164         }
 165         return CPRESELWK;
 166 }
 167
 168 static inline void compressor_selector_update(int lz4sz, int didwk, int wksz) {
 169         VM_COMPRESSOR_STAT(compressor_stats.lz4_compressions++);
 170
 171         if (lz4sz == 0) {
 172                 VM_COMPRESSOR_STAT(compressor_stats.lz4_compressed_bytes+=PAGE_SIZE);
 173                 VM_COMPRESSOR_STAT(compressor_stats.lz4_compression_failures++);
 174                 vmcstate.lz4_failure_run_length++;
 175                 VM_COMPRESSOR_STAT(vmcstate.lz4_total_failures++);
 176                 vmcstate.lz4_run_length = 0;
 177         } else {
 178                 vmcstate.lz4_failure_run_length = 0;
 179
 180                 VM_COMPRESSOR_STAT(compressor_stats.lz4_compressed_bytes+=lz4sz);
 181
 182                 if (lz4sz <= vmctune.wkdm_reeval_threshold) {
 183                         vmcstate.lz4_run_length = 0;
 184                 } else {
 185                         if (!didwk) {
 186                                 vmcstate.lz4_run_length++;
 187                         }
 188                 }
 189
 190                 if (didwk) {
 191                         if (__probable(wksz > lz4sz)) {
 192                                 uint32_t lz4delta = wksz - lz4sz;
 193                                 VM_COMPRESSOR_STAT(compressor_stats.lz4_wk_compression_delta+=lz4delta);
 194                                 if (lz4delta >= vmctune.lz4_run_continue_bytes) {
 195                                         vmcstate.lz4_run_length++;
 196                                 } else if (lz4delta <= vmctune.lz4_profitable_bytes) {
 197                                         vmcstate.lz4_failure_run_length++;
 198                                         VM_COMPRESSOR_STAT(vmcstate.lz4_total_unprofitables++);
 199                                         vmcstate.lz4_run_length = 0;
 200                                 } else {
 201                                         vmcstate.lz4_run_length = 0;
 202                                 }
 203                         } else {
 204                                 VM_COMPRESSOR_STAT(compressor_stats.lz4_wk_compression_negative_delta+=(lz4sz-wksz));
 205                                 vmcstate.lz4_failure_run_length++;
 206                                 VM_COMPRESSOR_STAT(vmcstate.lz4_total_negatives++);
 207                                 vmcstate.lz4_run_length = 0;
 208                         }
 209                 }
 210         }
 211 }
 212
 213
 214 static inline void WKdm_hv(uint32_t *wkbuf) {
 215 #if DEVELOPMENT || DEBUG
 216         uint32_t *inw = (uint32_t *) wkbuf;
 217         if (*inw != MZV_MAGIC) {
 218                 if ((*inw | *(inw + 1) | *(inw + 2)) & 0xFFFF0000) {
 219                         panic("WKdm(%p): invalid header 0x%x 0x%x 0x%x\n", wkbuf, *inw, *(inw +1), *(inw+2));
 220                 }
 221         }
 222 #else /* DEVELOPMENT || DEBUG */
 223         (void) wkbuf;
 224 #endif
 225 }
 226
 227 //todo fix clang diagnostic
 228 #pragma clang diagnostic push
 229 #pragma clang diagnostic ignored "-Wincompatible-pointer-types"
 230
 231 #if defined(__arm64__)
 232 #endif
 233
 234 static inline void WKdmD(WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, unsigned int bytes) {
 235 #if defined(__arm64__)
 236 #endif
 237         WKdm_hv(src_buf);
 238 #if defined(__arm64__)
 239         if (PAGE_SIZE == 4096) {
 240                 WKdm_decompress_4k(src_buf, dest_buf, scratch, bytes);
 241         } else {
 242                 __unused uint64_t wdsstart;
 243
 244                 VM_COMPRESSOR_STAT_DBG(wdsstart = mach_absolute_time());
 245                 WKdm_decompress_16k(src_buf, dest_buf, scratch, bytes);
 246
 247                 VM_COMPRESSOR_STAT_DBG(compressor_stats.wks_dabstime += mach_absolute_time() - wdsstart);
 248                 VM_COMPRESSOR_STAT(compressor_stats.wks_decompressions++);
 249         }
 250 #else /* !defined arm64 */
 251         WKdm_decompress_new(src_buf, dest_buf, scratch, bytes);
 252 #endif
 253 }
 254 #if DEVELOPMENT || DEBUG
 255 int precompy, wkswhw;
 256 #endif
 257
 258 static inline int WKdmC(WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, boolean_t *incomp_copy, unsigned int limit) {
 259         (void)incomp_copy;
 260         int wkcval;
 261 #if defined(__arm64__)
 262         if (PAGE_SIZE == 4096) {
 263                 wkcval = WKdm_compress_4k(src_buf, dest_buf, scratch, limit);
 264         } else {
 265                 __unused uint64_t wcswstart;
 266
 267                 VM_COMPRESSOR_STAT_DBG(wcswstart = mach_absolute_time());
 268
 269                 int wkswsz = WKdm_compress_16k(src_buf, dest_buf, scratch, limit);
 270
 271                 VM_COMPRESSOR_STAT_DBG(compressor_stats.wks_cabstime += mach_absolute_time() - wcswstart);
 272                 VM_COMPRESSOR_STAT(compressor_stats.wks_compressions++);
 273                 wkcval = wkswsz;
 274         }
 275 #else
 276         wkcval = WKdm_compress_new(src_buf, dest_buf, scratch, limit);
 277 #endif
 278         return wkcval;
 279 }
 280
 281
 282 int metacompressor(const uint8_t *in, uint8_t *cdst, int32_t outbufsz, uint16_t *codec, void *cscratchin, boolean_t *incomp_copy) {
 283         int sz = -1;
 284         int dowk = FALSE, dolz4 = FALSE, skiplz4 = FALSE;
 285         int insize = PAGE_SIZE;
 286         compressor_encode_scratch_t *cscratch = cscratchin;
 287
 288         if (vm_compressor_current_codec == CMODE_WK) {
 289                 dowk = TRUE;
 290         } else if (vm_compressor_current_codec == CMODE_LZ4) {
 291                 dolz4 = TRUE;
 292         } else if (vm_compressor_current_codec == CMODE_HYB) {
 293                 enum compressor_preselect_t presel = compressor_preselect();
 294                 if (presel == CPRESELLZ4) {
 295                         dolz4 = TRUE;
 296                         goto lz4compress;
 297                 } else if (presel == CSKIPLZ4) {
 298                         dowk = TRUE;
 299                         skiplz4 = TRUE;
 300                 } else {
 301                         assert(presel == CPRESELWK);
 302                         dowk = TRUE;
 303                 }
 304         }
 305
 306         if (dowk) {
 307                 *codec = CCWK;
 308                 VM_COMPRESSOR_STAT(compressor_stats.wk_compressions++);
 309                 sz = WKdmC(in, cdst, &cscratch->wkscratch[0], incomp_copy, outbufsz);
 310
 311                 if (sz == -1) {
 312                         VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=PAGE_SIZE);
 313                         VM_COMPRESSOR_STAT(compressor_stats.wk_compression_failures++);
 314
 315                         if (vm_compressor_current_codec == CMODE_HYB) {
 316                                 goto lz4eval;
 317                         }
 318                         goto cexit;
 319                 } else if (sz == 0) {
 320                         VM_COMPRESSOR_STAT(compressor_stats.wk_sv_compressions++);
 321                         VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=4);
 322                 } else {
 323                         VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=sz);
 324                 }
 325         }
 326 lz4eval:
 327         if (vm_compressor_current_codec == CMODE_HYB) {
 328                 if (((sz == -1) || (sz >= vmctune.lz4_threshold)) && (skiplz4 == FALSE)) {
 329                         dolz4 = TRUE;
 330                 } else {
 331 #if DEVELOPMENT || DEBUG
 332                         int wkc = (sz == -1) ? PAGE_SIZE : sz;
 333 #endif
 334                         VM_COMPRESSOR_STAT(compressor_stats.wk_compressions_exclusive++);
 335                         VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_exclusive+=wkc);
 336                         goto cexit;
 337                 }
 338         }
 339
 340 lz4compress:
 341
 342         if (dolz4) {
 343                 if (sz == -1) {
 344                         sz = PAGE_SIZE;
 345                 }
 346                 int wksz = sz;
 347                 *codec = CCLZ4;
 348
 349                 sz = (int) lz4raw_encode_buffer(cdst, outbufsz, in, insize, &cscratch->lz4state[0]);
 350
 351                 compressor_selector_update(sz, dowk, wksz);
 352                 if (sz == 0) {
 353                         sz = -1;
 354                         goto cexit;
 355                 }
 356         }
 357 cexit:
 358         return sz;
 359 }
 360
 361 void metadecompressor(const uint8_t *source, uint8_t *dest, uint32_t csize, uint16_t ccodec, void *compressor_dscratchin) {
 362         int dolz4 = (ccodec == CCLZ4);
 363         int rval;
 364         compressor_decode_scratch_t *compressor_dscratch = compressor_dscratchin;
 365
 366         if (dolz4) {
 367                 rval = (int)lz4raw_decode_buffer(dest, PAGE_SIZE, source, csize, &compressor_dscratch->lz4decodestate[0]);
 368                 VM_DECOMPRESSOR_STAT(compressor_stats.lz4_decompressions+=1);
 369                 VM_DECOMPRESSOR_STAT(compressor_stats.lz4_decompressed_bytes+=csize);
 370 #if DEVELOPMENT || DEBUG
 371                 uint32_t *d32 = dest;
 372 #endif
 373                 assertf(rval == PAGE_SIZE, "LZ4 decode: size != pgsize %d, header: 0x%x, 0x%x, 0x%x",
 374                     rval, *d32, *(d32+1), *(d32+2));
 375         } else {
 376                 assert(ccodec == CCWK);
 377
 378                 WKdmD(source, dest, &compressor_dscratch->wkdecompscratch[0], csize);
 379
 380                 VM_DECOMPRESSOR_STAT(compressor_stats.wk_decompressions+=1);
 381                 VM_DECOMPRESSOR_STAT(compressor_stats.wk_decompressed_bytes+=csize);
 382         }
 383 }
 384 #pragma clang diagnostic pop
 385
 386 uint32_t vm_compressor_get_encode_scratch_size(void) {
 387         if (vm_compressor_current_codec != VM_COMPRESSOR_DEFAULT_CODEC) {
 388                 return MAX(sizeof(compressor_encode_scratch_t), WKdm_SCRATCH_BUF_SIZE_INTERNAL);
 389         } else {
 390                 return WKdm_SCRATCH_BUF_SIZE_INTERNAL;
 391         }
 392 }
 393
 394 uint32_t vm_compressor_get_decode_scratch_size(void) {
 395         if (vm_compressor_current_codec != VM_COMPRESSOR_DEFAULT_CODEC) {
 396                 return MAX(sizeof(compressor_decode_scratch_t), WKdm_SCRATCH_BUF_SIZE_INTERNAL);
 397         } else {
 398                 return WKdm_SCRATCH_BUF_SIZE_INTERNAL;
 399         }
 400 }
 401
 402
 403 int vm_compressor_algorithm(void) {
 404         return vm_compressor_current_codec;
 405 }
 406
 407 void vm_compressor_algorithm_init(void) {
 408         vm_compressor_mode_t new_codec = VM_COMPRESSOR_DEFAULT_CODEC;
 409
 410 #if defined(__arm64__)
 411         new_codec = CMODE_HYB;
 412
 413         if (PAGE_SIZE == 16384) {
 414                 vmctune.lz4_threshold = 12288;
 415         }
 416 #endif
 417
 418         PE_parse_boot_argn("vm_compressor_codec", &new_codec, sizeof(new_codec));
 419         assertf(((new_codec == VM_COMPRESSOR_DEFAULT_CODEC) || (new_codec == CMODE_WK) ||
 420                 (new_codec == CMODE_LZ4) || (new_codec == CMODE_HYB)),
 421             "Invalid VM compression codec: %u", new_codec);
 422
 423 #if defined(__arm__)||defined(__arm64__)
 424         uint32_t tmpc;
 425         if (PE_parse_boot_argn("-vm_compressor_wk", &tmpc, sizeof(tmpc))) {
 426                 new_codec = VM_COMPRESSOR_DEFAULT_CODEC;
 427         } else if (PE_parse_boot_argn("-vm_compressor_hybrid", &tmpc, sizeof(tmpc))) {
 428                 new_codec = CMODE_HYB;
 429         }
 430
 431         vm_compressor_current_codec = new_codec;
 432 #endif /* arm/arm64 */
 433 }