'\" t
.\"     Title: blk_queue_io_opt
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: Block Devices
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "BLK_QUEUE_IO_OPT" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Block Devices"
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.SH "NAME"
blk_queue_io_opt \- set optimal request size for the queue
.SH "SYNOPSIS"
.HP \w'void\ blk_queue_io_opt('u
.BI "void blk_queue_io_opt(struct\ request_queue\ *\ " "q" ", unsigned\ int\ " "opt" ");"
.SH "ARGUMENTS"
.PP
\fIq\fR
.RS 4
the request queue for the device
.RE
.PP
\fIopt\fR
.RS 4
optimal request size in bytes
.RE
.SH "DESCRIPTION"
.PP
Storage devices may report an optimal I/O size, which is the device\*(Aqs preferred unit for sustained I/O\&. This is rarely reported for disk drives\&. For RAID arrays it is usually the stripe width or the internal track size\&. A properly aligned multiple of optimal_io_size is the preferred request size for workloads where sustained throughput is desired\&.
.SH "COPYRIGHT"
.br