Add vsync io engine
It uses readv/writev to transfer the data and coalesces adjacent
data into a single system call (emulating queueing).
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/README b/README
index 4c58d37..940839c 100644
--- a/README
+++ b/README
@@ -136,14 +136,16 @@
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,
- 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.
+ psync for regular pread/pwrite io, vsync for regular
+ readv/writev (with queuing emulation) 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,