1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>idr_preload</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="idr.html" title="idr/ida Functions"><link rel="prev" href="idr.html" title="idr/ida Functions"><link rel="next" href="API-idr-alloc.html" title="idr_alloc"></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"><span class="phrase">idr_preload</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="idr.html">Prev</a>&#160;</td><th width="60%" align="center">idr/ida Functions</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-idr-alloc.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-idr-preload"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>idr_preload &#8212; 
2  preload for <code class="function">idr_alloc</code>
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <b class="fsfunc">idr_preload </b>(</code></td><td>gfp_t <var class="pdparam">gfp_mask</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1123567132"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>gfp_mask</code></em></span></dt><dd><p>
4     allocation mask to use for preloading
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1123568764"></a><h2>Description</h2><p>
6   Preload per-cpu layer buffer for <code class="function">idr_alloc</code>.  Can only be used from
7   process context and each <code class="function">idr_preload</code> invocation should be matched with
8   <code class="function">idr_preload_end</code>.  Note that preemption is disabled while preloaded.
9   </p><p>
10
11   The first <code class="function">idr_alloc</code> in the preloaded section can be treated as if it
12   were invoked with <em class="parameter"><code>gfp_mask</code></em> used for preloading.  This allows using more
13   permissive allocation masks for idrs protected by spinlocks.
14   </p><p>
15
16   For example, if <code class="function">idr_alloc</code> below fails, the failure can be treated as
17   if <code class="function">idr_alloc</code> were called with GFP_KERNEL rather than GFP_NOWAIT.
18   </p><p>
19
20   idr_preload(GFP_KERNEL);
21   spin_lock(lock);
22   </p><p>
23
24   id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT);
25   </p><p>
26
27   spin_unlock(lock);
28   <code class="function">idr_preload_end</code>;
29   if (id &lt; 0)
30   error;
31</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="idr.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="idr.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-idr-alloc.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">idr/ida Functions&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">idr_alloc</span></td></tr></table></div></body></html>
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