From 8253a66bea54ce36e4cc34378c4eed06a07de65b Mon Sep 17 00:00:00 2001 From: Vincent Fu Date: Fri, 4 Feb 2022 15:59:37 -0500 Subject: [PATCH] HOWTO: combine separate hipri listings into a single one Resolve doc build warnings about multiple appearances of the hipri option. Signed-off-by: Vincent Fu --- HOWTO.rst | 54 +++++++++++++++++++++++++++++------------------------- 1 file changed, 29 insertions(+), 25 deletions(-) diff --git a/HOWTO.rst b/HOWTO.rst index db30ed1f..0e49d8a8 100644 --- a/HOWTO.rst +++ b/HOWTO.rst @@ -2247,14 +2247,6 @@ with the caveat that when used on the command line, they must come after the map and release for each IO. This is more efficient, and reduces the IO latency as well. -.. option:: hipri : [io_uring] - - 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. The benefits are more efficient IO for high IOPS - scenarios, and lower latencies for low queue depth IO. - .. option:: registerfiles : [io_uring] With this option, fio registers the set of files being used with the @@ -2275,6 +2267,35 @@ with the caveat that when used on the command line, they must come after the When :option:`sqthread_poll` is set, this option provides a way to define which CPU should be used for the polling thread. +.. option:: hipri + + [io_uring] + + 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. The benefits are more efficient IO for high IOPS + scenarios, and lower latencies for low queue depth IO. + + + [pvsync2] + + Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority + than normal. + + + [sg] + + If this option is set, fio will attempt to use polled IO completions. + This will have a similar effect as (io_uring)hipri. Only SCSI READ and + WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor + VERIFY). Older versions of the Linux sg driver that do not support + hipri will simply ignore this flag and do normal IO. The Linux SCSI + Low Level Driver (LLD) that "owns" the device also needs to support + hipri (also known as iopoll and mq_poll). The MegaRAID driver is an + example of a SCSI LLD. Default: clear (0) which does normal + (interrupted based) IO. + .. option:: userspace_reap : [libaio] Normally, with the libaio engine in use, fio will use the @@ -2283,11 +2304,6 @@ with the caveat that when used on the command line, they must come after the reap events. The reaping mode is only enabled when polling for a minimum of 0 events (e.g. when :option:`iodepth_batch_complete` `=0`). -.. option:: hipri : [pvsync2] - - Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority - than normal. - .. option:: hipri_percentage : [pvsync2] When hipri is set this determines the probability of a pvsync2 I/O being high @@ -2597,18 +2613,6 @@ with the caveat that when used on the command line, they must come after the a valid stream identifier) fio will open a stream and then close it when done. Default is 0. -.. option:: hipri : [sg] - - If this option is set, fio will attempt to use polled IO completions. - This will have a similar effect as (io_uring)hipri. Only SCSI READ and - WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor - VERIFY). Older versions of the Linux sg driver that do not support - hipri will simply ignore this flag and do normal IO. The Linux SCSI - Low Level Driver (LLD) that "owns" the device also needs to support - hipri (also known as iopoll and mq_poll). The MegaRAID driver is an - example of a SCSI LLD. Default: clear (0) which does normal - (interrupted based) IO. - .. option:: http_host=str : [http] Hostname to connect to. For S3, this could be the bucket hostname. -- 2.25.1