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/*
* $PostgreSQL: pgsql/src/tools/fsync/test_fsync.c,v 1.29 2010/07/04 13:42:51 momjian Exp $
*
*
* test_fsync.c
* test various fsync() methods
*/
#include "postgres.h"
#include "access/xlog_internal.h"
#include "access/xlog.h"
#include "access/xlogdefs.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <unistd.h>
#include <string.h>
#ifdef WIN32
#define FSYNC_FILENAME "./test_fsync.out"
#else
/* /tmp might be a memory file system */
#define FSYNC_FILENAME "/var/tmp/test_fsync.out"
#endif
#define WRITE_SIZE (8 * 1024) /* 8k */
#define LABEL_FORMAT "\t%-30s"
int loops = 10000;
void die(char *str);
void print_elapse(struct timeval start_t, struct timeval stop_t);
int
main(int argc, char *argv[])
{
struct timeval start_t;
struct timeval stop_t;
int tmpfile,
i;
char *full_buf = (char *) malloc(XLOG_SEG_SIZE),
*buf;
char *filename = FSYNC_FILENAME;
if (argc > 2 && strcmp(argv[1], "-f") == 0)
{
filename = argv[2];
argv += 2;
argc -= 2;
}
if (argc > 1)
loops = atoi(argv[1]);
for (i = 0; i < XLOG_SEG_SIZE; i++)
full_buf[i] = random();
if ((tmpfile = open(filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR, 0)) == -1)
die("Cannot open output file.");
if (write(tmpfile, full_buf, XLOG_SEG_SIZE) != XLOG_SEG_SIZE)
die("write failed");
/* fsync now so later fsync's don't have to do it */
if (fsync(tmpfile) != 0)
die("fsync failed");
close(tmpfile);
buf = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, full_buf);
printf("Loops = %d\n\n", loops);
/*
* Simple write
*/
printf("Simple write:\n");
/* write only */
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
close(tmpfile);
}
gettimeofday(&stop_t, NULL);
printf(LABEL_FORMAT, "8k write");
print_elapse(start_t, stop_t);
/*
* Compare file sync methods with one 8k write
*/
printf("\nCompare file sync methods using one write:\n");
#ifdef OPEN_DATASYNC_FLAG
/* open_dsync, write */
if ((tmpfile = open(filename, O_RDWR | O_DSYNC, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "open_datasync 8k write");
print_elapse(start_t, stop_t);
#else
printf("\t(open_datasync unavailable)\n");
#endif
#ifdef OPEN_SYNC_FLAG
/* open_fsync, write */
if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "open_sync 8k write");
print_elapse(start_t, stop_t);
#else
printf("\t(open_sync unavailable)\n");
#endif
#ifdef HAVE_FDATASYNC
/* write, fdatasync */
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
fdatasync(tmpfile);
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "8k write, fdatasync");
print_elapse(start_t, stop_t);
#else
printf("\t(fdatasync unavailable)\n");
#endif
/* write, fsync, close */
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (fsync(tmpfile) != 0)
die("fsync failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "8k write, fsync");
print_elapse(start_t, stop_t);
/*
* Compare file sync methods with two 8k write
*/
printf("\nCompare file sync methods using two writes:\n");
#ifdef OPEN_DATASYNC_FLAG
/* open_dsync, write */
if ((tmpfile = open(filename, O_RDWR | O_DSYNC, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "2 open_datasync 8k writes");
print_elapse(start_t, stop_t);
#else
printf("\t(open_datasync unavailable)\n");
#endif
#ifdef OPEN_SYNC_FLAG
/* open_fsync, write */
if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "2 open_sync 8k writes");
print_elapse(start_t, stop_t);
#endif
#ifdef HAVE_FDATASYNC
/* write, fdatasync */
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
fdatasync(tmpfile);
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "8k write, 8k write, fdatasync");
print_elapse(start_t, stop_t);
#else
printf("\t(fdatasync unavailable)\n");
#endif
/* write, fsync, close */
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (fsync(tmpfile) != 0)
die("fsync failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "8k write, 8k write, fsync");
print_elapse(start_t, stop_t);
/*
* Compare 1 to 2 writes
*/
printf("\nCompare open_sync with different sizes:\n");
#ifdef OPEN_SYNC_FLAG
/* 16k open_sync write */
if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE * 2) != WRITE_SIZE * 2)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "open_sync 16k write");
print_elapse(start_t, stop_t);
/* Two 8k open_sync writes */
if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
die("Cannot open output file.");
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
gettimeofday(&stop_t, NULL);
close(tmpfile);
printf(LABEL_FORMAT, "2 open_sync 8k writes");
print_elapse(start_t, stop_t);
#else
printf("\t(open_sync unavailable)\n");
#endif
/*
* Fsync another file descriptor?
*/
printf("\nTest if fsync on non-write file descriptor is honored:\n");
printf("(If the times are similar, fsync() can sync data written\n");
printf("on a different descriptor.)\n");
/* write, fsync, close */
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
if (fsync(tmpfile) != 0)
die("fsync failed");
close(tmpfile);
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
/* do nothing but the open/close the tests are consistent. */
close(tmpfile);
}
gettimeofday(&stop_t, NULL);
printf(LABEL_FORMAT, "8k write, fsync, close");
print_elapse(start_t, stop_t);
/* write, close, fsync */
gettimeofday(&start_t, NULL);
for (i = 0; i < loops; i++)
{
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
die("write failed");
close(tmpfile);
/* reopen file */
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("Cannot open output file.");
if (fsync(tmpfile) != 0)
die("fsync failed");
close(tmpfile);
}
gettimeofday(&stop_t, NULL);
printf(LABEL_FORMAT, "8k write, close, fsync");
print_elapse(start_t, stop_t);
/* cleanup */
free(full_buf);
unlink(filename);
return 0;
}
void
print_elapse(struct timeval start_t, struct timeval stop_t)
{
double total_time = (stop_t.tv_sec - start_t.tv_sec) +
/* usec subtraction might be negative, e.g. 5.4 - 4.8 */
(stop_t.tv_usec - start_t.tv_usec) * 0.000001;
double per_second = loops / total_time;
printf("%9.3f/second\n", per_second);
}
void
die(char *str)
{
fprintf(stderr, "%s\n", str);
exit(1);
}
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