If the option accepts an upper and lower range, use a colon ':' or
minus '-' to separate such values. See :ref:`irange <irange>`.
+ If the lower value specified happens to be larger than the upper value,
+ two values are swapped.
.. _bool:
blocks given. For example, if you give 32 as a parameter, fio will sync the
file for every 32 writes issued. If fio is using non-buffered I/O, we may
not sync the file. The exception is the sg I/O engine, which synchronizes
- the disk cache anyway.
+ the disk cache anyway. Defaults to 0, which means no sync every certain
+ number of writes.
.. option:: fdatasync=int
Like :option:`fsync` but uses :manpage:`fdatasync(2)` to only sync data and
not metadata blocks. In Windows, FreeBSD, and DragonFlyBSD there is no
:manpage:`fdatasync(2)`, this falls back to using :manpage:`fsync(2)`.
+ Defaults to 0, which means no sync data every certain number of writes.
.. option:: write_barrier=int
**mmapshared**
Same as mmap, but use a MMAP_SHARED mapping.
+ **cudamalloc**
+ Use GPU memory as the buffers for GPUDirect RDMA benchmark.
+
The area allocated is a function of the maximum allowed bs size for the job,
multiplied by the I/O depth given. Note that for **shmhuge** and
**mmaphuge** to work, the system must have free huge pages allocated. This
**sync**
Basic :manpage:`read(2)` or :manpage:`write(2)`
I/O. :manpage:`lseek(2)` is used to position the I/O location.
+ See :option:`fsync` and :option:`fdatasync` for syncing write I/Os.
**psync**
Basic :manpage:`pread(2)` or :manpage:`pwrite(2)` I/O. Default on
DDIR_TRIM
does fallocate(,mode = FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE).
+ **ftruncate**
+ I/O engine that sends :manpage:`ftruncate(2)` operations in response
+ to write (DDIR_WRITE) events. Each ftruncate issued sets the file's
+ size to the current block offset. Block size is ignored.
+
**e4defrag**
I/O engine that does regular EXT4_IOC_MOVE_EXT ioctls to simulate
defragment activity in request to DDIR_WRITE event.
.. option:: cpuload=int : [cpuio]
- Attempt to use the specified percentage of CPU cycles.
+ Attempt to use the specified percentage of CPU cycles. This is a mandatory
+ option when using cpuio I/O engine.
.. option:: cpuchunks=int : [cpuio]