From 454154e66e93b3dc314955c197a21eeacbe69c78 Mon Sep 17 00:00:00 2001 From: Ankit Kumar Date: Wed, 11 May 2022 22:00:18 +0530 Subject: [PATCH] docs: documentation for xnvme ioengine Signed-off-by: Ankit Kumar Link: https://lore.kernel.org/r/20220511163019.5608-3-ankit.kumar@samsung.com Signed-off-by: Jens Axboe --- HOWTO.rst | 55 +++++++++++++++++++++++++++++++++++++++++-- fio.1 | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 121 insertions(+), 4 deletions(-) diff --git a/HOWTO.rst b/HOWTO.rst index 6a3e09f5..84bea5c5 100644 --- a/HOWTO.rst +++ b/HOWTO.rst @@ -2171,6 +2171,12 @@ I/O engine **exec** Execute 3rd party tools. Could be used to perform monitoring during jobs runtime. + **xnvme** + I/O engine using the xNVMe C API, for NVMe devices. The xnvme engine provides + flexibility to access GNU/Linux Kernel NVMe driver via libaio, IOCTLs, io_uring, + the SPDK NVMe driver, or your own custom NVMe driver. The xnvme engine includes + engine specific options. (See https://xnvme.io). + I/O engine specific parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -2260,7 +2266,7 @@ with the caveat that when used on the command line, they must come after the making the submission and completion part more lightweight. Required for the below :option:`sqthread_poll` option. -.. option:: sqthread_poll : [io_uring] +.. option:: sqthread_poll : [io_uring] [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 @@ -2275,7 +2281,7 @@ with the caveat that when used on the command line, they must come after the .. option:: hipri - [io_uring] + [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 @@ -2725,6 +2731,51 @@ with the caveat that when used on the command line, they must come after the If set, stdout and stderr streams are redirected to files named from the job name. Default is true. +.. option:: xnvme_async=str : [xnvme] + + Select the xnvme async command interface. This can take these values. + + **emu** + This is default and used to emulate asynchronous I/O. + **thrpool** + Use thread pool for Asynchronous I/O. + **io_uring** + Use Linux io_uring/liburing for Asynchronous I/O. + **libaio** + Use Linux aio for Asynchronous I/O. + **posix** + Use POSIX aio for Asynchronous I/O. + **nil** + Use nil-io; For introspective perf. evaluation + +.. option:: xnvme_sync=str : [xnvme] + + Select the xnvme synchronous command interface. This can take these values. + + **nvme** + This is default and uses Linux NVMe Driver ioctl() for synchronous I/O. + **psync** + Use pread()/write() for synchronous I/O. + +.. option:: xnvme_admin=str : [xnvme] + + Select the xnvme admin command interface. This can take these values. + + **nvme** + This is default and uses linux NVMe Driver ioctl() for admin commands. + **block** + Use Linux Block Layer ioctl() and sysfs for admin commands. + **file_as_ns** + Use file-stat to construct NVMe idfy responses. + +.. option:: xnvme_dev_nsid=int : [xnvme] + + xnvme namespace identifier, for userspace NVMe driver. + +.. option:: xnvme_iovec=int : [xnvme] + + If this option is set. xnvme will use vectored read/write commands. + I/O depth ~~~~~~~~~ diff --git a/fio.1 b/fio.1 index 609947dc..ded7bbfc 100644 --- a/fio.1 +++ b/fio.1 @@ -1965,6 +1965,12 @@ via kernel NFS. .TP .B exec Execute 3rd party tools. Could be used to perform monitoring during jobs runtime. +.TP +.B xnvme +I/O engine using the xNVMe C API, for NVMe devices. The xnvme engine provides +flexibility to access GNU/Linux Kernel NVMe driver via libaio, IOCTLs, io_uring, +the SPDK NVMe driver, or your own custom NVMe driver. The xnvme engine includes +engine specific options. (See \fIhttps://xnvme.io/\fR). .SS "I/O engine specific parameters" In addition, there are some parameters which are only valid when a specific \fBioengine\fR is in use. These are used identically to normal parameters, @@ -2039,7 +2045,7 @@ 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)hipri +.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 completions do not. Hence they are require active reaping by the application. @@ -2052,7 +2058,7 @@ 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)sqthread_poll +.BI (io_uring,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 @@ -2480,6 +2486,66 @@ Defines the time between the SIGTERM and SIGKILL signals. Default is 1 second. .TP .BI (exec)std_redirect\fR=\fbool If set, stdout and stderr streams are redirected to files named from the job name. Default is true. +.TP +.BI (xnvme)xnvme_async\fR=\fPstr +Select the xnvme async command interface. This can take these values. +.RS +.RS +.TP +.B emu +This is default and used to emulate asynchronous I/O +.TP +.BI thrpool +Use thread pool for Asynchronous I/O +.TP +.BI io_uring +Use Linux io_uring/liburing for Asynchronous I/O +.TP +.BI libaio +Use Linux aio for Asynchronous I/O +.TP +.BI posix +Use POSIX aio for Asynchronous I/O +.TP +.BI nil +Use nil-io; For introspective perf. evaluation +.RE +.RE +.TP +.BI (xnvme)xnvme_sync\fR=\fPstr +Select the xnvme synchronous command interface. This can take these values. +.RS +.RS +.TP +.B nvme +This is default and uses Linux NVMe Driver ioctl() for synchronous I/O +.TP +.BI psync +Use pread()/write() for synchronous I/O +.RE +.RE +.TP +.BI (xnvme)xnvme_admin\fR=\fPstr +Select the xnvme admin command interface. This can take these values. +.RS +.RS +.TP +.B nvme +This is default and uses Linux NVMe Driver ioctl() for admin commands +.TP +.BI block +Use Linux Block Layer ioctl() and sysfs for admin commands +.TP +.BI file_as_ns +Use file-stat as to construct NVMe idfy responses +.RE +.RE +.TP +.BI (xnvme)xnvme_dev_nsid\fR=\fPint +xnvme namespace identifier, for userspace NVMe driver. +.TP +.BI (xnvme)xnvme_iovec +If this option is set, xnvme will use vectored read/write commands. .SS "I/O depth" .TP .BI iodepth \fR=\fPint -- 2.25.1