--- /dev/null
+/*
+ * Copyright (c) 2010-2016 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+/* This module implements a hybrid/adaptive compression scheme, using WKdm where
+ * profitable and, currently, an LZ4 variant elsewhere.
+ * (Created 2016, Derek Kumar)
+ */
+#include "lz4.h"
+#include "WKdm_new.h"
+#include <vm/vm_compressor_algorithms.h>
+#include <vm/vm_compressor.h>
+
+#define MZV_MAGIC (17185)
+#define LZ4_SCRATCH_ALIGN (64)
+#define WKC_SCRATCH_ALIGN (64)
+
+#define LZ4_SCRATCH_ALIGN (64)
+#define WKC_SCRATCH_ALIGN (64)
+
+#define memcpy_T_NT memcpy
+#define memcpy_NT_T memcpy
+
+typedef union {
+ uint8_t lz4state[lz4_encode_scratch_size]__attribute((aligned(LZ4_SCRATCH_ALIGN)));
+ uint8_t wkscratch[0] __attribute((aligned(WKC_SCRATCH_ALIGN))); // TODO
+} compressor_encode_scratch_t;
+
+typedef union {
+ uint8_t lz4decodestate[lz4_encode_scratch_size]__attribute((aligned(64)));
+ uint8_t wkdecompscratch[0] __attribute((aligned(64)));
+} compressor_decode_scratch_t;
+
+typedef struct {
+ uint16_t lz4_selection_run;
+ uint16_t lz4_run_length;
+ uint16_t lz4_preselects;
+ uint32_t lz4_total_preselects;
+ uint16_t lz4_failure_skips;
+ uint32_t lz4_total_failure_skips;
+ uint16_t lz4_failure_run_length;
+ uint16_t lz4_total_unprofitables;
+ uint32_t lz4_total_negatives;
+ uint32_t lz4_total_failures;
+} compressor_state_t;
+
+compressor_tuneables_t vmctune = {
+ .lz4_threshold = 2048,
+ .wkdm_reeval_threshold = 1536,
+ .lz4_max_failure_skips = 0,
+ .lz4_max_failure_run_length = ~0U,
+ .lz4_max_preselects = 0,
+ .lz4_run_preselection_threshold = ~0U,
+ .lz4_run_continue_bytes = 0,
+ .lz4_profitable_bytes = 0,
+};
+
+compressor_state_t vmcstate = {
+ .lz4_selection_run = 0,
+ .lz4_run_length = 0,
+ .lz4_preselects = 0,
+ .lz4_total_preselects = 0,
+ .lz4_failure_skips = 0,
+ .lz4_total_failure_skips = 0,
+ .lz4_failure_run_length = 0,
+ .lz4_total_unprofitables = 0,
+ .lz4_total_negatives = 0,
+};
+
+compressor_stats_t compressor_stats;
+
+enum compressor_preselect_t {
+ CPRESELLZ4 = 0,
+ CSKIPLZ4 = 1,
+ CPRESELWK = 2,
+};
+
+vm_compressor_mode_t vm_compressor_current_codec = VM_COMPRESSOR_DEFAULT_CODEC;
+
+boolean_t verbose = FALSE;
+
+#if DEVELOPMENT || DEBUG
+#define VERBOSE(x...) \
+ do { \
+ if (verbose) \
+ printf(x); \
+ } while(0)
+#define VM_COMPRESSOR_STAT(x...) \
+ do { \
+ (x); \
+ } while(0)
+//TODO make atomic where needed, decompression paths
+#define VM_DECOMPRESSOR_STAT(x...) \
+ do { \
+ (x); \
+ } while(0)
+#else
+#define VERBOSE(x...) \
+ do { \
+ }while (0)
+#define VM_COMPRESSOR_STAT(x...) \
+ do { \
+ }while (0)
+#define VM_DECOMPRESSOR_STAT(x...) \
+ do { \
+ }while (0)
+#endif
+
+static inline enum compressor_preselect_t compressor_preselect(void) {
+ if (vmcstate.lz4_failure_skips >= vmctune.lz4_max_failure_skips) {
+ vmcstate.lz4_failure_skips = 0;
+ vmcstate.lz4_failure_run_length = 0;
+ }
+
+ if (vmcstate.lz4_failure_run_length >= vmctune.lz4_max_failure_run_length) {
+ vmcstate.lz4_failure_skips++;
+ vmcstate.lz4_total_failure_skips++;
+ return CSKIPLZ4;
+ }
+
+ if (vmcstate.lz4_preselects >= vmctune.lz4_max_preselects) {
+ vmcstate.lz4_preselects = 0;
+ return CPRESELWK;
+ }
+
+ if (vmcstate.lz4_run_length >= vmctune.lz4_run_preselection_threshold) {
+ vmcstate.lz4_preselects++;
+ vmcstate.lz4_total_preselects++;
+ return CPRESELLZ4;
+ }
+ return CPRESELWK;
+}
+
+static inline void compressor_selector_update(int lz4sz, int didwk, int wksz) {
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_compressions++);
+
+ if (lz4sz == 0) {
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_compressed_bytes+=PAGE_SIZE);
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_compression_failures++);
+ vmcstate.lz4_failure_run_length++;
+ VM_COMPRESSOR_STAT(vmcstate.lz4_total_failures++);
+ vmcstate.lz4_run_length = 0;
+ } else {
+ vmcstate.lz4_failure_run_length = 0;
+
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_compressed_bytes+=lz4sz);
+
+ if (lz4sz <= vmctune.wkdm_reeval_threshold) {
+ vmcstate.lz4_run_length = 0;
+ } else {
+ if (!didwk) {
+ vmcstate.lz4_run_length++;
+ }
+ }
+
+ if (didwk) {
+ if (__probable(wksz > lz4sz)) {
+ uint32_t lz4delta = wksz - lz4sz;
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_wk_compression_delta+=lz4delta);
+ if (lz4delta >= vmctune.lz4_run_continue_bytes) {
+ vmcstate.lz4_run_length++;
+ } else if (lz4delta <= vmctune.lz4_profitable_bytes) {
+ vmcstate.lz4_failure_run_length++;
+ VM_COMPRESSOR_STAT(vmcstate.lz4_total_unprofitables++);
+ vmcstate.lz4_run_length = 0;
+ } else {
+ vmcstate.lz4_run_length = 0;
+ }
+ } else {
+ VM_COMPRESSOR_STAT(compressor_stats.lz4_wk_compression_negative_delta+=(lz4sz-wksz));
+ vmcstate.lz4_failure_run_length++;
+ VM_COMPRESSOR_STAT(vmcstate.lz4_total_negatives++);
+ vmcstate.lz4_run_length = 0;
+ }
+ }
+ }
+}
+
+//todo fix clang diagnostic
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wincompatible-pointer-types"
+
+static inline void WKdmD(WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, unsigned int bytes) {
+#if DEVELOPMENT || DEBUG
+ uint32_t *inw = (uint32_t *) src_buf;
+ if (*inw != MZV_MAGIC) {
+ if ((*inw | *(inw+1) | *(inw+2)) & 0xFFFF0000) {
+ panic("WKdmDecompress: invalid header 0x%x 0x%x 0x%x\n", *inw, *(inw +1), *(inw+2));
+ }
+ }
+#endif /* DEVELOPMENT || DEBUG */
+ WKdm_decompress_new(src_buf, dest_buf, scratch, bytes);
+}
+
+static inline int WKdmC(WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, unsigned int limit) {
+ return WKdm_compress_new(src_buf, dest_buf, scratch, limit);
+}
+
+
+int metacompressor(const uint8_t *in, uint8_t *cdst, int32_t outbufsz, uint16_t *codec, void *cscratchin) {
+ int sz = -1;
+ int dowk = FALSE, dolz4 = FALSE, skiplz4 = FALSE;
+ int insize = PAGE_SIZE;
+ compressor_encode_scratch_t *cscratch = cscratchin;
+
+ if (vm_compressor_current_codec == CMODE_WK) {
+ dowk = TRUE;
+ } else if (vm_compressor_current_codec == CMODE_LZ4) {
+ dolz4 = TRUE;
+ } else if (vm_compressor_current_codec == CMODE_HYB) {
+ enum compressor_preselect_t presel = compressor_preselect();
+ if (presel == CPRESELLZ4) {
+ dolz4 = TRUE;
+ goto lz4compress;
+ } else if (presel == CSKIPLZ4) {
+ dowk = TRUE;
+ skiplz4 = TRUE;
+ } else {
+ assert(presel == CPRESELWK);
+ dowk = TRUE;
+ }
+ }
+
+ if (dowk) {
+ *codec = CCWK;
+ sz = WKdmC(in, cdst, &cscratch->wkscratch[0], outbufsz);
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressions++);
+
+ VERBOSE("WKDm Compress: %d\n", sz);
+ if (sz == -1) {
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=PAGE_SIZE);
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compression_failures++);
+
+ if (vm_compressor_current_codec == CMODE_HYB) {
+ goto lz4eval;
+ }
+ goto cexit;
+ } else if (sz == 0) {
+ VM_COMPRESSOR_STAT(compressor_stats.wk_sv_compressions++);
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=8);
+ } else {
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_total+=sz);
+ }
+ }
+lz4eval:
+ if (vm_compressor_current_codec == CMODE_HYB) {
+ if (((sz == -1) || (sz >= vmctune.lz4_threshold)) && (skiplz4 == FALSE)) {
+ dolz4 = TRUE;
+ } else {
+ __unused int wkc = (sz == -1) ? PAGE_SIZE : sz;
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressions_exclusive++);
+ VM_COMPRESSOR_STAT(compressor_stats.wk_compressed_bytes_exclusive+=wkc);
+ goto cexit;
+ }
+ }
+
+lz4compress:
+
+ if (dolz4) {
+ if (sz == -1) {
+ sz = PAGE_SIZE;
+ }
+ int wksz = sz;
+ *codec = CCLZ4;
+
+ sz = (int) lz4raw_encode_buffer(cdst, outbufsz, in, insize, &cscratch->lz4state[0]);
+
+ VERBOSE("LZ4 Compress: %d\n", sz);
+ compressor_selector_update(sz, dowk, wksz);
+ if (sz == 0) {
+ sz = -1;
+ goto cexit;
+ }
+ }
+cexit:
+ return sz;
+}
+
+void metadecompressor(const uint8_t *source, uint8_t *dest, uint32_t csize, uint16_t ccodec, void *compressor_dscratchin) {
+ int dolz4 = (ccodec == CCLZ4);
+ int rval;
+ compressor_decode_scratch_t *compressor_dscratch = compressor_dscratchin;
+
+ if (dolz4) {
+ rval = (int)lz4raw_decode_buffer(dest, PAGE_SIZE, source, csize, &compressor_dscratch->lz4decodestate[0]);
+ VM_DECOMPRESSOR_STAT(compressor_stats.lz4_decompressions+=1);
+ VM_DECOMPRESSOR_STAT(compressor_stats.lz4_decompressed_bytes+=csize);
+
+ assertf(rval == PAGE_SIZE, "LZ4 decode: size != pgsize %d", rval);
+
+ } else {
+ assert(ccodec == CCWK);
+ WKdmD(source, dest, &compressor_dscratch->wkdecompscratch[0], csize);
+ VM_DECOMPRESSOR_STAT(compressor_stats.wk_decompressions+=1);
+ VM_DECOMPRESSOR_STAT(compressor_stats.wk_decompressed_bytes+=csize);
+ }
+}
+#pragma clang diagnostic pop
+
+uint32_t vm_compressor_get_encode_scratch_size(void) {
+ if (vm_compressor_current_codec != VM_COMPRESSOR_DEFAULT_CODEC) {
+ return MAX(sizeof(compressor_encode_scratch_t), WKdm_SCRATCH_BUF_SIZE_INTERNAL);
+ } else {
+ return WKdm_SCRATCH_BUF_SIZE_INTERNAL;
+ }
+}
+
+uint32_t vm_compressor_get_decode_scratch_size(void) {
+ if (vm_compressor_current_codec != VM_COMPRESSOR_DEFAULT_CODEC) {
+ return MAX(sizeof(compressor_decode_scratch_t), WKdm_SCRATCH_BUF_SIZE_INTERNAL);
+ } else {
+ return WKdm_SCRATCH_BUF_SIZE_INTERNAL;
+ }
+}
+
+
+int vm_compressor_algorithm(void) {
+ return vm_compressor_current_codec;
+}
+
+void vm_compressor_algorithm_init(void) {
+ vm_compressor_mode_t new_codec = VM_COMPRESSOR_DEFAULT_CODEC;
+
+
+ PE_parse_boot_argn("vm_compressor_codec", &new_codec, sizeof(new_codec));
+ assertf(((new_codec == VM_COMPRESSOR_DEFAULT_CODEC) || (new_codec == CMODE_WK) ||
+ (new_codec == CMODE_LZ4) || (new_codec = CMODE_HYB)),
+ "Invalid VM compression codec: %u", new_codec);
+
+
+ if (PE_parse_boot_argn("-vm_compressor_wk", &new_codec, sizeof(new_codec))) {
+ new_codec = VM_COMPRESSOR_DEFAULT_CODEC;
+ } else if (PE_parse_boot_argn("-vm_compressor_hybrid", &new_codec, sizeof(new_codec))) {
+ new_codec = CMODE_HYB;
+ }
+
+}
+//TODO check open-sourceability of lz4
projects / apple / xnu.git / blobdiff