/*
* pg_fsync --- do fsync with or without writethrough
*/
int
pg_fsync(int fd)
{
#ifndef HAVE_FSYNC_WRITETHROUGH_ONLY
if (sync_method != SYNC_METHOD_FSYNC_WRITETHROUGH)
return pg_fsync_no_writethrough(fd);
else
#endif
return pg_fsync_writethrough(fd);
}
static void
test_sync(int writes_per_op)
{
int tmpfile,
ops,
writes;
bool fs_warning = false;
if (writes_per_op == 1)
printf("\nCompare file sync methods using one %dkB write:\n", XLOG_BLCKSZ_K);
else
printf("\nCompare file sync methods using two %dkB writes:\n", XLOG_BLCKSZ_K);
printf("(in wal_sync_method preference order, except fdatasync\n");
printf("is Linux's default)\n");
/*
* Test open_datasync if available
*/
printf(LABEL_FORMAT, "open_datasync");
fflush(stdout);
#ifdef OPEN_DATASYNC_FLAG
if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
{
printf(NA_FORMAT, "n/a*\n");
fs_warning = true;
}
else
{
if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
die("could not open output file");
START_TIMER;
for (ops = 0; alarm_triggered == false; ops++)
{
for (writes = 0; writes < writes_per_op; writes++)
if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
STOP_TIMER;
close(tmpfile);
}
#else
printf(NA_FORMAT, "n/a\n");
#endif
/*
* Test fdatasync if available
*/
printf(LABEL_FORMAT, "fdatasync");
fflush(stdout);
#ifdef HAVE_FDATASYNC
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("could not open output file");
START_TIMER;
for (ops = 0; alarm_triggered == false; ops++)
{
for (writes = 0; writes < writes_per_op; writes++)
if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
die("write failed");
fdatasync(tmpfile);
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
STOP_TIMER;
close(tmpfile);
#else
printf(NA_FORMAT, "n/a\n");
#endif
/*
* Test fsync
*/
printf(LABEL_FORMAT, "fsync");
fflush(stdout);
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("could not open output file");
START_TIMER;
for (ops = 0; alarm_triggered == false; ops++)
{
for (writes = 0; writes < writes_per_op; writes++)
if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
die("write failed");
if (fsync(tmpfile) != 0)
die("fsync failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
STOP_TIMER;
close(tmpfile);
/*
* If fsync_writethrough is available, test as well
*/
printf(LABEL_FORMAT, "fsync_writethrough");
fflush(stdout);
#ifdef HAVE_FSYNC_WRITETHROUGH
if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
die("could not open output file");
START_TIMER;
for (ops = 0; alarm_triggered == false; ops++)
{
for (writes = 0; writes < writes_per_op; writes++)
if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
die("write failed");
if (pg_fsync_writethrough(tmpfile) != 0)
die("fsync failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
STOP_TIMER;
close(tmpfile);
#else
printf(NA_FORMAT, "n/a\n");
#endif
/*
* Test open_sync if available
*/
printf(LABEL_FORMAT, "open_sync");
fflush(stdout);
#ifdef OPEN_SYNC_FLAG
if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
{
printf(NA_FORMAT, "n/a*\n");
fs_warning = true;
}
else
{
START_TIMER;
for (ops = 0; alarm_triggered == false; ops++)
{
for (writes = 0; writes < writes_per_op; writes++)
if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
die("write failed");
if (lseek(tmpfile, 0, SEEK_SET) == -1)
die("seek failed");
}
STOP_TIMER;
close(tmpfile);
}
#else
printf(NA_FORMAT, "n/a\n");
#endif
if (fs_warning)
{
printf("* This file system and its mount options do not support direct\n");
printf("I/O, e.g. ext4 in journaled mode.\n");
}
}