'\" t
.\"     Title: blk_queue_max_hw_sectors
.\"    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_MAX_HW_SEC" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Block Devices"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
blk_queue_max_hw_sectors \- set max sectors for a request for this queue
.SH "SYNOPSIS"
.HP \w'void\ blk_queue_max_hw_sectors('u
.BI "void blk_queue_max_hw_sectors(struct\ request_queue\ *\ " "q" ", unsigned\ int\ " "max_hw_sectors" ");"
.SH "ARGUMENTS"
.PP
\fIq\fR
.RS 4
the request queue for the device
.RE
.PP
\fImax_hw_sectors\fR
.RS 4
max hardware sectors in the usual 512b unit
.RE
.SH "DESCRIPTION"
.PP
Enables a low level driver to set a hard upper limit, max_hw_sectors, on the size of requests\&. max_hw_sectors is set by the device driver based upon the capabilities of the I/O controller\&.
.PP
max_dev_sectors is a hard limit imposed by the storage device for READ/WRITE requests\&. It is set by the disk driver\&.
.PP
max_sectors is a soft limit imposed by the block layer for filesystem type requests\&. This value can be overridden on a per\-device basis in /sys/block/<device>/queue/max_sectors_kb\&. The soft limit can not exceed max_hw_sectors\&.
.SH "COPYRIGHT"
.br