'\" t
.\"     Title: wait_on_bit
.\"    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: Driver Basics
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "WAIT_ON_BIT" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Driver Basics"
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.SH "NAME"
wait_on_bit \- wait for a bit to be cleared
.SH "SYNOPSIS"
.HP \w'int\ wait_on_bit('u
.BI "int wait_on_bit(unsigned\ long\ *\ " "word" ", int\ " "bit" ", unsigned\ " "mode" ");"
.SH "ARGUMENTS"
.PP
\fIword\fR
.RS 4
the word being waited on, a kernel virtual address
.RE
.PP
\fIbit\fR
.RS 4
the bit of the word being waited on
.RE
.PP
\fImode\fR
.RS 4
the task state to sleep in
.RE
.SH "DESCRIPTION"
.PP
There is a standard hashed waitqueue table for generic use\&. This is the part of the hashtable\*(Aqs accessor API that waits on a bit\&. For instance, if one were to have waiters on a bitflag, one would call
\fBwait_on_bit\fR
in threads waiting for the bit to clear\&. One uses
\fBwait_on_bit\fR
where one is waiting for the bit to clear, but has no intention of setting it\&. Returned value will be zero if the bit was cleared, or non\-zero if the process received a signal and the mode permitted wakeup on that signal\&.
.SH "COPYRIGHT"
.br