'\" t
.\"     Title: mutex_lock
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: June 2017
.\"    Manual: Mutex API reference
.\"    Source: Kernel Hackers Manual 4.11.3
.\"  Language: English
.\"
.TH "MUTEX_LOCK" "9" "June 2017" "Kernel Hackers Manual 4\&.11\&" "Mutex API reference"
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.SH "NAME"
mutex_lock \- acquire the mutex
.SH "SYNOPSIS"
.HP \w'void\ __sched\ mutex_lock('u
.BI "void __sched mutex_lock(struct\ mutex\ *\ " "lock" ");"
.SH "ARGUMENTS"
.PP
\fIstruct mutex * lock\fR
.RS 4
the mutex to be acquired
.RE
.SH "DESCRIPTION"
.PP
Lock the mutex exclusively for this task\&. If the mutex is not available right now, it will sleep until it can get it\&.
.PP
The mutex must later on be released by the same task that acquired it\&. Recursive locking is not allowed\&. The task may not exit without first unlocking the mutex\&. Also, kernel memory where the mutex resides must not be freed with the mutex still locked\&. The mutex must first be initialized (or statically defined) before it can be locked\&.
\fBmemset\fR\-ing the mutex to 0 is not allowed\&.
.PP
( The CONFIG_DEBUG_MUTEXES \&.config option turns on debugging checks that will enforce the restrictions and will also do deadlock debugging\&. )
.PP
This function is similar to (but not equivalent to)
\fBdown\fR\&.
.SH "AUTHOR"
.PP
\fBRusty Russell\fR <\&rusty@rustcorp.com.au\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br