Update documentation with io_uring_cmd I/O engine specific options. Add missing io_uring I/O engine entry from fio man page. Update docs with missing io_uring engine specific options. Signed-off-by: Ankit Kumar <ankit.kumar@xxxxxxxxxxx> --- HOWTO.rst | 39 ++++++++++++++++++++++++++++++--------- fio.1 | 28 +++++++++++++++++++++++++--- 2 files changed, 55 insertions(+), 12 deletions(-) diff --git a/HOWTO.rst b/HOWTO.rst index 84bea5c5..fb06a788 100644 --- a/HOWTO.rst +++ b/HOWTO.rst @@ -1948,6 +1948,10 @@ I/O engine for both direct and buffered IO. This engine defines engine specific options. + **io_uring_cmd** + Fast Linux native asynchronous I/O for pass through commands. + This engine defines engine specific options. + **libaio** Linux native asynchronous I/O. Note that Linux may only support queued behavior with non-buffered I/O (set ``direct=1`` or @@ -2253,20 +2257,32 @@ with the caveat that when used on the command line, they must come after the .. option:: fixedbufs : [io_uring] - If fio is asked to do direct IO, then Linux will map pages for each - IO call, and release them when IO is done. If this option is set, the - pages are pre-mapped before IO is started. This eliminates the need to - map and release for each IO. This is more efficient, and reduces the - IO latency as well. + If fio is asked to do direct IO, then Linux will map pages for each + IO call, and release them when IO is done. If this option is set, the + pages are pre-mapped before IO is started. This eliminates the need to + map and release for each IO. This is more efficient, and reduces the + IO latency as well. + +.. option:: nonvectored : [io_uring] [io_uring_cmd] + + With this option, fio will use non-vectored read/write commands, where + address must contain the address directly. -.. option:: registerfiles : [io_uring] +.. option:: force_async=int : [io_uring] [io_uring_cmd] + + Normal operation for io_uring is to try and issue an sqe as + non-blocking first, and if that fails, execute it in an async manner. + With this option set to N, then every N request fio will ask sqe to + be issued in an async manner. + +.. option:: registerfiles : [io_uring] [io_uring_cmd] With this option, fio registers the set of files being used with the kernel. This avoids the overhead of managing file counts in the kernel, making the submission and completion part more lightweight. Required for the below :option:`sqthread_poll` option. -.. option:: sqthread_poll : [io_uring] [xnvme] +.. option:: sqthread_poll : [io_uring] [io_uring_cmd] [xnvme] Normally fio will submit IO by issuing a system call to notify the kernel of available items in the SQ ring. If this option is set, the @@ -2274,14 +2290,19 @@ with the caveat that when used on the command line, they must come after the This frees up cycles for fio, at the cost of using more CPU in the system. -.. option:: sqthread_poll_cpu : [io_uring] +.. option:: sqthread_poll_cpu : [io_uring] [io_uring_cmd] When :option:`sqthread_poll` is set, this option provides a way to define which CPU should be used for the polling thread. +.. option:: cmd_type=str : [io_uring_cmd] + + Specifies the type of uring passthrough command to be used. Supported + value is nvme. + .. option:: hipri - [io_uring], [xnvme] + [io_uring] [xnvme] If this option is set, fio will attempt to use polled IO completions. Normal IO completions generate interrupts to signal the completion of diff --git a/fio.1 b/fio.1 index ded7bbfc..66d4adbb 100644 --- a/fio.1 +++ b/fio.1 @@ -1738,6 +1738,15 @@ Basic \fBpreadv\fR\|(2) or \fBpwritev\fR\|(2) I/O. .B pvsync2 Basic \fBpreadv2\fR\|(2) or \fBpwritev2\fR\|(2) I/O. .TP +.B io_uring +Fast Linux native asynchronous I/O. Supports async IO +for both direct and buffered IO. +This engine defines engine specific options. +.TP +.B io_uring_cmd +Fast Linux native asynchronous I/O for passthrough commands. +This engine defines engine specific options. +.TP .B libaio Linux native asynchronous I/O. Note that Linux may only support queued behavior with non-buffered I/O (set `direct=1' or @@ -2045,6 +2054,15 @@ release them when IO is done. If this option is set, the pages are pre-mapped before IO is started. This eliminates the need to map and release for each IO. This is more efficient, and reduces the IO latency as well. .TP +.BI (io_uring,io_uring_cmd)nonvectored +With this option, fio will use non-vectored read/write commands, where address +must contain the address directly. +.TP +.BI (io_uring,io_uring_cmd)force_async +Normal operation for io_uring is to try and issue an sqe as non-blocking first, +and if that fails, execute it in an async manner. With this option set to N, +then every N request fio will ask sqe to be issued in an async manner. +.TP .BI (io_uring,xnvme)hipri If this option is set, fio will attempt to use polled IO completions. Normal IO completions generate interrupts to signal the completion of IO, polled @@ -2052,22 +2070,26 @@ completions do not. Hence they are require active reaping by the application. The benefits are more efficient IO for high IOPS scenarios, and lower latencies for low queue depth IO. .TP -.BI (io_uring)registerfiles +.BI (io_uring,io_uring_cmd)registerfiles With this option, fio registers the set of files being used with the kernel. This avoids the overhead of managing file counts in the kernel, making the submission and completion part more lightweight. Required for the below sqthread_poll option. .TP -.BI (io_uring,xnvme)sqthread_poll +.BI (io_uring,io_uring_cmd,xnvme)sqthread_poll Normally fio will submit IO by issuing a system call to notify the kernel of available items in the SQ ring. If this option is set, the act of submitting IO will be done by a polling thread in the kernel. This frees up cycles for fio, at the cost of using more CPU in the system. .TP -.BI (io_uring)sqthread_poll_cpu +.BI (io_uring,io_uring_cmd)sqthread_poll_cpu When `sqthread_poll` is set, this option provides a way to define which CPU should be used for the polling thread. .TP +.BI (io_uring_cmd)cmd_type \fR=\fPstr +Specifies the type of uring passthrough command to be used. Supported +value is nvme. +.TP .BI (libaio)userspace_reap Normally, with the libaio engine in use, fio will use the \fBio_getevents\fR\|(3) system call to reap newly returned events. With -- 2.17.1