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md5/shaXsum: use FEATURE_COPYBUF_KB to size the buffer instead of fixed 4k

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function                                             old     new   delta
md5_sha1_sum_main                                    536     565     +29
hash_file                                            419     401     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 29/-18)             Total: 11 bytes

In my test, for unrolled sha1, COPYBUF_KB=64 increases throughput
from 367 MB/s to 457 MB/s.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2022-01-04 00:50:32 +01:00
parent 7abb2bb96e
commit 1fc520ed28
1 changed files with 14 additions and 7 deletions
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21
coreutils/md5_sha1_sum.c
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@ -151,10 +151,12 @@ static unsigned char *hash_bin_to_hex(unsigned char *hash_value,
return (unsigned char *)hex_value; return (unsigned char *)hex_value;
} }
#define BUFSZ (CONFIG_FEATURE_COPYBUF_KB < 4 ? 4096 : CONFIG_FEATURE_COPYBUF_KB * 1024)
#if !ENABLE_SHA3SUM #if !ENABLE_SHA3SUM
# define hash_file(f,w) hash_file(f) # define hash_file(b,f,w) hash_file(b,f)
#endif #endif
static uint8_t *hash_file(const char *filename, unsigned sha3_width) static uint8_t *hash_file(unsigned char *in_buf, const char *filename, unsigned sha3_width)
{ {
int src_fd, hash_len, count; int src_fd, hash_len, count;
union _ctx_ { union _ctx_ {
@ -227,8 +229,7 @@ static uint8_t *hash_file(const char *filename, unsigned sha3_width)
} }
{ {
RESERVE_CONFIG_UBUFFER(in_buf, 4096); while ((count = safe_read(src_fd, in_buf, BUFSZ)) > 0) {
while ((count = safe_read(src_fd, in_buf, 4096)) > 0) {
update(&context, in_buf, count); update(&context, in_buf, count);
} }
hash_value = NULL; hash_value = NULL;
@ -238,7 +239,6 @@ static uint8_t *hash_file(const char *filename, unsigned sha3_width)
final(&context, in_buf); final(&context, in_buf);
hash_value = hash_bin_to_hex(in_buf, hash_len); hash_value = hash_bin_to_hex(in_buf, hash_len);
} }
RELEASE_CONFIG_BUFFER(in_buf);
} }
if (src_fd != STDIN_FILENO) { if (src_fd != STDIN_FILENO) {
@ -251,6 +251,7 @@ static uint8_t *hash_file(const char *filename, unsigned sha3_width)
int md5_sha1_sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int md5_sha1_sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int md5_sha1_sum_main(int argc UNUSED_PARAM, char **argv) int md5_sha1_sum_main(int argc UNUSED_PARAM, char **argv)
{ {
unsigned char *in_buf;
int return_value = EXIT_SUCCESS; int return_value = EXIT_SUCCESS;
unsigned flags; unsigned flags;
#if ENABLE_SHA3SUM #if ENABLE_SHA3SUM
@ -279,6 +280,12 @@ int md5_sha1_sum_main(int argc UNUSED_PARAM, char **argv)
if (!*argv) if (!*argv)
*--argv = (char*)"-"; *--argv = (char*)"-";
/* The buffer is not alloc/freed for each input file:
* for big values of COPYBUF_KB, this helps to keep its pages
* pre-faulted and possibly even fully cached on local CPU.
*/
in_buf = xmalloc(BUFSZ);
do { do {
if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && (flags & FLAG_CHECK)) { if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && (flags & FLAG_CHECK)) {
FILE *pre_computed_stream; FILE *pre_computed_stream;
@ -310,7 +317,7 @@ int md5_sha1_sum_main(int argc UNUSED_PARAM, char **argv)
*filename_ptr = '\0'; *filename_ptr = '\0';
filename_ptr += 2; filename_ptr += 2;
hash_value = hash_file(filename_ptr, sha3_width); hash_value = hash_file(in_buf, filename_ptr, sha3_width);
if (hash_value && (strcmp((char*)hash_value, line) == 0)) { if (hash_value && (strcmp((char*)hash_value, line) == 0)) {
if (!(flags & FLAG_SILENT)) if (!(flags & FLAG_SILENT))
@ -339,7 +346,7 @@ int md5_sha1_sum_main(int argc UNUSED_PARAM, char **argv)
} }
fclose_if_not_stdin(pre_computed_stream); fclose_if_not_stdin(pre_computed_stream);
} else { } else {
uint8_t *hash_value = hash_file(*argv, sha3_width); uint8_t *hash_value = hash_file(in_buf, *argv, sha3_width);
if (hash_value == NULL) { if (hash_value == NULL) {
return_value = EXIT_FAILURE; return_value = EXIT_FAILURE;
} else { } else {