1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Some Functions Which Don't Sleep</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Unreliable Guide To Locking"><link rel="up" href="sleeping-things.html" title="Chapter 10. What Functions Are Safe To Call From Interrupts?"><link rel="prev" href="sleeping-things.html" title="Chapter 10. What Functions Are Safe To Call From Interrupts?"><link rel="next" href="apiref-mutex.html" title="Chapter 11. Mutex API reference"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Some Functions Which Don't Sleep</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="sleeping-things.html">Prev</a> </td><th width="60%" align="center">Chapter 10. What Functions Are Safe To Call From Interrupts?</th><td width="20%" align="right"> <a accesskey="n" href="apiref-mutex.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="dont-sleep"></a>Some Functions Which Don't Sleep</h2></div></div></div><p> 2 Some functions are safe to call from any context, or holding 3 almost any lock. 4 </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> 5 <code class="function">printk()</code> 6 </p></li><li class="listitem"><p> 7 <code class="function">kfree()</code> 8 </p></li><li class="listitem"><p> 9 <code class="function">add_timer()</code> and <code class="function">del_timer()</code> 10 </p></li></ul></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sleeping-things.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sleeping-things.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="apiref-mutex.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 10. What Functions Are Safe To Call From Interrupts? </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 11. Mutex API reference</td></tr></table></div></body></html> 11