From 44a31a9c2f54aa497a2b946232132991aa78a595 Mon Sep 17 00:00:00 2001 From: Alasdair Kergon Date: Mon, 27 Sep 2010 19:09:34 +0000 Subject: [PATCH] Speed up CRC32 calculations by using a larger lookup table. Use -DDEBUG_CRC32 to revert to old function and check new one gives same result. --- VERSION | 2 +- VERSION_DM | 2 +- WHATS_NEW | 6 ++- WHATS_NEW_DM | 3 ++ lib/config/config.c | 4 +- lib/config/config.h | 2 +- lib/format_text/format-text.c | 8 ++-- lib/label/label.c | 8 ++-- lib/misc/crc.c | 84 +++++++++++++++++++++++++++++++++-- lib/misc/crc.h | 2 +- lib/misc/crc_gen.c | 47 ++++++++++++++++++++ make.tmpl.in | 1 + 12 files changed, 151 insertions(+), 18 deletions(-) create mode 100644 lib/misc/crc_gen.c diff --git a/VERSION b/VERSION index b426edc39..7efaa09a1 100644 --- a/VERSION +++ b/VERSION @@ -1 +1 @@ -2.02.74(2)-cvs (2010-09-24) +2.02.75(2)-cvs (2010-09-24) diff --git a/VERSION_DM b/VERSION_DM index 6f7212080..06677536f 100644 --- a/VERSION_DM +++ b/VERSION_DM @@ -1 +1 @@ -1.02.55-cvs (2010-09-24) +1.02.56-cvs (2010-09-24) diff --git a/WHATS_NEW b/WHATS_NEW index 25e9f330b..51959eb56 100644 --- a/WHATS_NEW +++ b/WHATS_NEW @@ -1,3 +1,7 @@ +Version 2.02.75 - +===================================== + Speed up CRC32 calculations by using a larger lookup table. + Version 2.02.74 - 24th September 2010 ===================================== Allow : and @ to be escaped with \ in device names of PVs. @@ -17,7 +21,7 @@ Version 2.02.74 - 24th September 2010 Add configure --with-default-data-alignment. Update heuristic used for default and detected data alignment. Add "devices/default_data_alignment" to lvm.conf. - Add implmentation for simple numeric 'get' property functions. + Add implementation for simple numeric 'get' property functions. Define GET_NUM_PROPERTY_FN macro to simplify numeric property 'get' function Add properties.[ch] to lib/report using columns.h. Add macro definitions to report infrastructure for character array length. diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM index ef4dfc7b0..892fd6883 100644 --- a/WHATS_NEW_DM +++ b/WHATS_NEW_DM @@ -1,3 +1,6 @@ +Version 1.02.56 - +===================================== + Version 1.02.55 - 24th September 2010 ===================================== Fix the way regions are marked complete to avoid slow --nosync cmirror I/O. diff --git a/lib/config/config.c b/lib/config/config.c index 333ff78af..72f306d71 100644 --- a/lib/config/config.c +++ b/lib/config/config.c @@ -239,8 +239,8 @@ int read_config_fd(struct config_tree *cft, struct device *dev, } if (checksum_fn && checksum != - (checksum_fn(checksum_fn(INITIAL_CRC, p->fb, size), - p->fb + size, size2))) { + (checksum_fn(checksum_fn(INITIAL_CRC, (uint8_t *)p->fb, size), + (uint8_t *)(p->fb + size), size2))) { log_error("%s: Checksum error", dev_name(dev)); goto out; } diff --git a/lib/config/config.h b/lib/config/config.h index da2956b94..2d16abdde 100644 --- a/lib/config/config.h +++ b/lib/config/config.h @@ -60,7 +60,7 @@ int override_config_tree_from_string(struct cmd_context *cmd, const char *config_settings); void destroy_config_tree(struct config_tree *cft); -typedef uint32_t (*checksum_fn_t) (uint32_t initial, const void *buf, uint32_t size); +typedef uint32_t (*checksum_fn_t) (uint32_t initial, const uint8_t *buf, uint32_t size); int read_config_fd(struct config_tree *cft, struct device *dev, off_t offset, size_t size, off_t offset2, size_t size2, diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c index 69233608c..1a03e84e9 100644 --- a/lib/format_text/format-text.c +++ b/lib/format_text/format-text.c @@ -332,7 +332,7 @@ struct mda_header *raw_read_mda_header(const struct format_type *fmt, if (!dev_read(dev_area->dev, dev_area->start, MDA_HEADER_SIZE, mdah)) goto_bad; - if (mdah->checksum_xl != xlate32(calc_crc(INITIAL_CRC, mdah->magic, + if (mdah->checksum_xl != xlate32(calc_crc(INITIAL_CRC, (uint8_t *)mdah->magic, MDA_HEADER_SIZE - sizeof(mdah->checksum_xl)))) { log_error("Incorrect metadata area header checksum on %s" @@ -380,7 +380,7 @@ static int _raw_write_mda_header(const struct format_type *fmt, mdah->start = start_byte; _xlate_mdah(mdah); - mdah->checksum_xl = xlate32(calc_crc(INITIAL_CRC, mdah->magic, + mdah->checksum_xl = xlate32(calc_crc(INITIAL_CRC, (uint8_t *)mdah->magic, MDA_HEADER_SIZE - sizeof(mdah->checksum_xl))); @@ -650,12 +650,12 @@ static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg, goto_out; } - mdac->rlocn.checksum = calc_crc(INITIAL_CRC, fidtc->raw_metadata_buf, + mdac->rlocn.checksum = calc_crc(INITIAL_CRC, (uint8_t *)fidtc->raw_metadata_buf, (uint32_t) (mdac->rlocn.size - new_wrap)); if (new_wrap) mdac->rlocn.checksum = calc_crc(mdac->rlocn.checksum, - fidtc->raw_metadata_buf + + (uint8_t *)fidtc->raw_metadata_buf + mdac->rlocn.size - new_wrap, (uint32_t) new_wrap); diff --git a/lib/label/label.c b/lib/label/label.c index 9fa505416..9a10d0664 100644 --- a/lib/label/label.c +++ b/lib/label/label.c @@ -142,8 +142,8 @@ static struct labeller *_find_labeller(struct device *dev, char *buf, sector + scan_sector); continue; } - if (calc_crc(INITIAL_CRC, &lh->offset_xl, LABEL_SIZE - - ((uintptr_t) &lh->offset_xl - (uintptr_t) lh)) != + if (calc_crc(INITIAL_CRC, (uint8_t *)&lh->offset_xl, LABEL_SIZE - + ((uint8_t *) &lh->offset_xl - (uint8_t *) lh)) != xlate32(lh->crc_xl)) { log_info("Label checksum incorrect on %s - " "ignoring", dev_name(dev)); @@ -323,8 +323,8 @@ int label_write(struct device *dev, struct label *label) if (!(label->labeller->ops->write)(label, buf)) return_0; - lh->crc_xl = xlate32(calc_crc(INITIAL_CRC, &lh->offset_xl, LABEL_SIZE - - ((uintptr_t) &lh->offset_xl - (uintptr_t) lh))); + lh->crc_xl = xlate32(calc_crc(INITIAL_CRC, (uint8_t *)&lh->offset_xl, LABEL_SIZE - + ((uint8_t *) &lh->offset_xl - (uint8_t *) lh))); if (!dev_open(dev)) return_0; diff --git a/lib/misc/crc.c b/lib/misc/crc.c index c69ee9303..75d1c60e1 100644 --- a/lib/misc/crc.c +++ b/lib/misc/crc.c @@ -18,7 +18,73 @@ #include "crc.h" /* Calculate an endian-independent CRC of supplied buffer */ -uint32_t calc_crc(uint32_t initial, const void *buf, uint32_t size) +#ifndef DEBUG_CRC32 +uint32_t calc_crc(uint32_t initial, const uint8_t *buf, uint32_t size) +#else +static uint32_t _calc_crc_new(uint32_t initial, const uint8_t *buf, uint32_t size) +#endif +{ + /* CRC-32 byte lookup table generated by crcgen.c */ + static const uint32_t crctab[] = { + 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, + 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, + 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, + 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, + 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, + 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, + 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, + 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, + 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, + 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, + 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, + 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, + 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, + 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, + 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, + 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, + 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, + 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, + 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, + 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, + 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, + 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, + 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, + 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, + 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, + 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, + 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, + 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, + 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, + 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, + 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, + 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, + }; + uint32_t *start = (uint32_t *) buf; + uint32_t *end = (uint32_t *) (buf + (size & 0xfffffffc)); + uint32_t crc = initial; + + /* Process 4 bytes per iteration */ + while (start < end) { + crc = crc ^ *start++; + crc = crctab[crc & 0xff] ^ crc >> 8; + crc = crctab[crc & 0xff] ^ crc >> 8; + crc = crctab[crc & 0xff] ^ crc >> 8; + crc = crctab[crc & 0xff] ^ crc >> 8; + } + + /* Process any bytes left over */ + buf = (uint8_t *) start; + size = size & 0x3; + while (size--) { + crc = crc ^ *buf++; + crc = crctab[crc & 0xff] ^ crc >> 8; + } + + return crc; +} + +#ifdef DEBUG_CRC32 +static uint32_t _calc_crc_old(uint32_t initial, const uint8_t *buf, uint32_t size) { static const uint32_t crctab[] = { 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, @@ -27,12 +93,24 @@ uint32_t calc_crc(uint32_t initial, const void *buf, uint32_t size) 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c }; uint32_t i, crc = initial; - const uint8_t *data = (const uint8_t *) buf; for (i = 0; i < size; i++) { - crc ^= *data++; + crc ^= *buf++; crc = (crc >> 4) ^ crctab[crc & 0xf]; crc = (crc >> 4) ^ crctab[crc & 0xf]; } return crc; } + +uint32_t calc_crc(uint32_t initial, const uint8_t *buf, uint32_t size) +{ + uint32_t new_crc = _calc_crc_new(initial, buf, size); + uint32_t old_crc = _calc_crc_old(initial, buf, size); + + if (new_crc != old_crc) + log_error(INTERNAL_ERROR "Old and new crc32 algorithms mismatch: 0x%08x != 0x%08x", old_crc, new_crc); + + return old_crc; +} + +#endif /* DEBUG_CRC32 */ diff --git a/lib/misc/crc.h b/lib/misc/crc.h index f7f99423a..2910bc55b 100644 --- a/lib/misc/crc.h +++ b/lib/misc/crc.h @@ -18,6 +18,6 @@ #define INITIAL_CRC 0xf597a6cf -uint32_t calc_crc(uint32_t initial, const void *buf, uint32_t size); +uint32_t calc_crc(uint32_t initial, const uint8_t *buf, uint32_t size); #endif diff --git a/lib/misc/crc_gen.c b/lib/misc/crc_gen.c new file mode 100644 index 000000000..846cca99b --- /dev/null +++ b/lib/misc/crc_gen.c @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2010 Red Hat, Inc. All rights reserved. + * + * This file is part of LVM2. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU Lesser General Public License v.2.1. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* + * Helper program to generate table included in crc.c. + */ +#include "lib.h" + +int main(int argc, char **argv) +{ + uint32_t crc, i, j; + + printf("\t/* CRC-32 byte lookup table generated by crcgen.c */\n"); + printf("\tstatic const uint32_t crctab[] = {"); + + for (i = 0; i < 256; i++) { + crc = i; + for (j = 0; j < 8; j++) { + if (crc & 1) + crc = 0xedb88320L ^ (crc >> 1); + else + crc = crc >> 1; + } + + if (i % 8) + printf(" "); + else + printf("\n\t\t"); + + printf("0x%08.8x,", crc); + } + + printf("\n\t};\n"); + + return 0; +} diff --git a/make.tmpl.in b/make.tmpl.in index 7cb0f6f09..d30da1a8b 100644 --- a/make.tmpl.in +++ b/make.tmpl.in @@ -113,6 +113,7 @@ CFLAGS += -fPIC -Wall -Wundef -Wshadow -Wcast-align -Wwrite-strings -Wmissing-pr #CFLAGS += -W -Wconversion -Wpointer-arith -Wbad-function-cast -Wcast-qual #CFLAGS += -pedantic -std=gnu99 +#CFLAGS += -DDEBUG_CRC32 CFLAGS += @COPTIMISE_FLAG@ -- 2.43.5