Add pread/pwrite support to sync engine
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/HOWTO b/HOWTO
index 5d757b2..24171e9 100644
--- a/HOWTO
+++ b/HOWTO
@@ -314,6 +314,8 @@
sync Basic read(2) or write(2) io. lseek(2) is
used to position the io location.
+ psync Basic pread(2) or pwrite(2) io.
+
libaio Linux native asynchronous io.
posixaio glibc posix asynchronous io.
diff --git a/README b/README
index f713f73..3ef13ea 100644
--- a/README
+++ b/README
@@ -120,13 +120,14 @@
size=x Set file size to x bytes (x string can include k/m/g)
ioengine=x 'x' may be: aio/libaio/linuxaio for Linux aio,
posixaio for POSIX aio, sync for regular read/write io,
- mmap for mmap'ed io, syslet-rw for syslet driven
- read/write, splice for using splice/vmsplice,
- sgio for direct SG_IO io, net for network io, or cpuio
- for a cycler burner load. sgio only works on Linux on
- SCSI (or SCSI-like devices, such as usb-storage or
- sata/libata driven) devices. Fio also has a null io
- engine, which is mainly used for testing fio itself.
+ psync for regular pread/pwrite io, mmap for mmap'ed io,
+ syslet-rw for syslet driven read/write, splice for using
+ splice/vmsplice, sgio for direct SG_IO io, net for
+ network io, or cpuio for a cycler burner load. sgio only
+ works on Linux on SCSI (or SCSI-like devices, such as
+ usb-storage or sata/libata driven) devices. Fio also has
+ a null io engine, which is mainly used for testing fio
+ itself.
iodepth=x For async io, allow 'x' ios in flight
overwrite=x If 'x', layout a write file first.
nrfiles=x Spread io load over 'x' number of files per job,
diff --git a/engines/sync.c b/engines/sync.c
index 597ee01..3cd4e90 100644
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -1,8 +1,8 @@
/*
- * sync engine
+ * sync/psync engine
*
* IO engine that does regular read(2)/write(2) with lseek(2) to transfer
- * data.
+ * data and IO engine that does regular pread(2)/pwrite(2) to transfer data.
*
*/
#include <stdio.h>
@@ -13,6 +13,8 @@
#include "../fio.h"
+#define is_psync(td) ((td)->io_ops->data == (void *) 1)
+
static int fio_syncio_prep(struct thread_data *td, struct io_u *io_u)
{
struct fio_file *f = io_u->file;
@@ -37,11 +39,17 @@
fio_ro_check(td, io_u);
- if (io_u->ddir == DDIR_READ)
- ret = read(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
- else if (io_u->ddir == DDIR_WRITE)
- ret = write(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
- else
+ if (io_u->ddir == DDIR_READ) {
+ if (is_psync(td))
+ ret = pread(f->fd, io_u->xfer_buf, io_u->xfer_buflen,io_u->offset);
+ else
+ ret = read(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
+ } else if (io_u->ddir == DDIR_WRITE) {
+ if (is_psync(td))
+ ret = pwrite(f->fd, io_u->xfer_buf, io_u->xfer_buflen,io_u->offset);
+ else
+ ret = write(f->fd, io_u->xfer_buf, io_u->xfer_buflen);
+ } else
ret = fsync(f->fd);
if (ret != (int) io_u->xfer_buflen) {
@@ -59,7 +67,13 @@
return FIO_Q_COMPLETED;
}
-static struct ioengine_ops ioengine = {
+static int fio_psyncio_init(struct thread_data *td)
+{
+ td->io_ops->data = (void *) 1;
+ return 0;
+}
+
+static struct ioengine_ops ioengine_rw = {
.name = "sync",
.version = FIO_IOOPS_VERSION,
.prep = fio_syncio_prep,
@@ -69,12 +83,24 @@
.flags = FIO_SYNCIO,
};
+static struct ioengine_ops ioengine_prw = {
+ .name = "psync",
+ .version = FIO_IOOPS_VERSION,
+ .queue = fio_syncio_queue,
+ .init = fio_psyncio_init,
+ .open_file = generic_open_file,
+ .close_file = generic_close_file,
+ .flags = FIO_SYNCIO,
+};
+
static void fio_init fio_syncio_register(void)
{
- register_ioengine(&ioengine);
+ register_ioengine(&ioengine_rw);
+ register_ioengine(&ioengine_prw);
}
static void fio_exit fio_syncio_unregister(void)
{
- unregister_ioengine(&ioengine);
+ unregister_ioengine(&ioengine_rw);
+ unregister_ioengine(&ioengine_prw);
}
diff --git a/fio.1 b/fio.1
index aacee10..35056a8 100644
--- a/fio.1
+++ b/fio.1
@@ -209,6 +209,9 @@
Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O. \fIfseek\fR\|(2) is used to
position the I/O location.
.TP
+.B psync
+Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O.
+.TP
.B libaio
Linux native asynchronous I/O.
.TP
diff --git a/options.c b/options.c
index 82d5ff5..e151634 100644
--- a/options.c
+++ b/options.c
@@ -336,6 +336,9 @@
{ .ival = "sync",
.help = "Use read/write",
},
+ { .ival = "psync",
+ .help = "Use pread/pwrite",
+ },
#ifdef FIO_HAVE_LIBAIO
{ .ival = "libaio",
.help = "Linux native asynchronous IO",