📄 sched.c
字号:
<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/kernel/sched.c</title><meta http-equiv=Content-Type content="text/html; charset=gb2312"><base href="http://oldlinux.org/lxr/http/"></head><body bgcolor=white><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/kernel/sched.c">区别标定</a>] [<a href="ident">标识符搜索</a>] [<a href="search">文本搜索</a>] [<a href="find">文件搜索</a>]</div><h1 align=center> <a href="http:/"> OldLinux</a> <a href="http:blurb.html"> 交叉引用</a><br> <a href="source/">Linux</a>/<a href="source/kernel/">kernel</a>/<a href="source/kernel/sched.c">sched.c</a></h1><div align=center> <b>版本:</b> [<a href="source/kernel/sched.c?v=1.0">1.0</a>] [<a href="source/kernel/sched.c?v=0.99.11">0.99.11</a>] [<a href="source/kernel/sched.c?v=0.99">0.99</a>] [<a href="source/kernel/sched.c?v=0.97">0.97</a>] [<a href="source/kernel/sched.c?v=0.96a">0.96a</a>] [<a href="source/kernel/sched.c?v=0.95">0.95</a>] [<a href="source/kernel/sched.c?v=0.12">0.12</a>] [<b><i>0.11</i></b>] [<a href="source/kernel/sched.c?v=0.01">0.01</a>] <br> <b>体系结构:</b> [<b><i>i386</i></b>] <br></div><hr><pre> <a name=L1 href="source/kernel/sched.c#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/kernel/sched.c#L2">2</a> <b><i> * linux/kernel/sched.c</i></b> <a name=L3 href="source/kernel/sched.c#L3">3</a> <b><i> *</i></b> <a name=L4 href="source/kernel/sched.c#L4">4</a> <b><i> * (C) 1991 Linus Torvalds</i></b> <a name=L5 href="source/kernel/sched.c#L5">5</a> <b><i> */</i></b> <a name=L6 href="source/kernel/sched.c#L6">6</a> <a name=L7 href="source/kernel/sched.c#L7">7</a> <b><i>/*</i></b> <a name=L8 href="source/kernel/sched.c#L8">8</a> <b><i> * 'sched.c' is the main kernel file. It contains scheduling primitives</i></b> <a name=L9 href="source/kernel/sched.c#L9">9</a> <b><i> * (sleep_on, wakeup, schedule etc) as well as a number of simple system</i></b> <a name=L10 href="source/kernel/sched.c#L10">10</a> <b><i> * call functions (type getpid(), which just extracts a field from</i></b> <a name=L11 href="source/kernel/sched.c#L11">11</a> <b><i> * current-task</i></b> <a name=L12 href="source/kernel/sched.c#L12">12</a> <b><i> */</i></b> <a name=L13 href="source/kernel/sched.c#L13">13</a> #include <linux/sched.h> <a name=L14 href="source/kernel/sched.c#L14">14</a> #include <linux/kernel.h> <a name=L15 href="source/kernel/sched.c#L15">15</a> #include <linux/sys.h> <a name=L16 href="source/kernel/sched.c#L16">16</a> #include <linux/fdreg.h> <a name=L17 href="source/kernel/sched.c#L17">17</a> #include <asm/system.h> <a name=L18 href="source/kernel/sched.c#L18">18</a> #include <asm/io.h> <a name=L19 href="source/kernel/sched.c#L19">19</a> #include <asm/segment.h> <a name=L20 href="source/kernel/sched.c#L20">20</a> <a name=L21 href="source/kernel/sched.c#L21">21</a> #include <signal.h> <a name=L22 href="source/kernel/sched.c#L22">22</a> <a name=L23 href="source/kernel/sched.c#L23">23</a> #define <a href="ident?i=_S">_S</a>(nr) (1<<((nr)-1)) <a name=L24 href="source/kernel/sched.c#L24">24</a> #define <a href="ident?i=_BLOCKABLE">_BLOCKABLE</a> (~(<a href="ident?i=_S">_S</a>(<a href="ident?i=SIGKILL">SIGKILL</a>) | <a href="ident?i=_S">_S</a>(<a href="ident?i=SIGSTOP">SIGSTOP</a>))) <a name=L25 href="source/kernel/sched.c#L25">25</a> <a name=L26 href="source/kernel/sched.c#L26">26</a> void <a href="ident?i=show_task">show_task</a>(int nr,struct <a href="ident?i=task_struct">task_struct</a> * p) <a name=L27 href="source/kernel/sched.c#L27">27</a> { <a name=L28 href="source/kernel/sched.c#L28">28</a> int i,j = 4096-sizeof(struct <a href="ident?i=task_struct">task_struct</a>); <a name=L29 href="source/kernel/sched.c#L29">29</a> <a name=L30 href="source/kernel/sched.c#L30">30</a> <a href="ident?i=printk">printk</a>(<i>"%d: pid=%d, state=%d, "</i>,nr,p->pid,p-><a href="ident?i=state">state</a>); <a name=L31 href="source/kernel/sched.c#L31">31</a> i=0; <a name=L32 href="source/kernel/sched.c#L32">32</a> while (i<j && !((char *)(p+1))[i]) <a name=L33 href="source/kernel/sched.c#L33">33</a> i++; <a name=L34 href="source/kernel/sched.c#L34">34</a> <a href="ident?i=printk">printk</a>(<i>"%d (of %d) chars free in kernel stack\n\r"</i>,i,j); <a name=L35 href="source/kernel/sched.c#L35">35</a> } <a name=L36 href="source/kernel/sched.c#L36">36</a> <a name=L37 href="source/kernel/sched.c#L37">37</a> void <a href="ident?i=show_stat">show_stat</a>(void) <a name=L38 href="source/kernel/sched.c#L38">38</a> { <a name=L39 href="source/kernel/sched.c#L39">39</a> int i; <a name=L40 href="source/kernel/sched.c#L40">40</a> <a name=L41 href="source/kernel/sched.c#L41">41</a> for (i=0;i<<a href="ident?i=NR_TASKS">NR_TASKS</a>;i++) <a name=L42 href="source/kernel/sched.c#L42">42</a> if (<a href="ident?i=task">task</a>[i]) <a name=L43 href="source/kernel/sched.c#L43">43</a> <a href="ident?i=show_task">show_task</a>(i,<a href="ident?i=task">task</a>[i]); <a name=L44 href="source/kernel/sched.c#L44">44</a> } <a name=L45 href="source/kernel/sched.c#L45">45</a> <a name=L46 href="source/kernel/sched.c#L46">46</a> #define <a href="ident?i=LATCH">LATCH</a> (1193180/<a href="ident?i=HZ">HZ</a>) <a name=L47 href="source/kernel/sched.c#L47">47</a> <a name=L48 href="source/kernel/sched.c#L48">48</a> extern void <a href="ident?i=mem_use">mem_use</a>(void); <a name=L49 href="source/kernel/sched.c#L49">49</a> <a name=L50 href="source/kernel/sched.c#L50">50</a> extern int <a href="ident?i=timer_interrupt">timer_interrupt</a>(void); <a name=L51 href="source/kernel/sched.c#L51">51</a> extern int <a href="ident?i=system_call">system_call</a>(void); <a name=L52 href="source/kernel/sched.c#L52">52</a> <a name=L53 href="source/kernel/sched.c#L53">53</a> union <a href="ident?i=task_union">task_union</a> { <a name=L54 href="source/kernel/sched.c#L54">54</a> struct <a href="ident?i=task_struct">task_struct</a> <a href="ident?i=task">task</a>; <a name=L55 href="source/kernel/sched.c#L55">55</a> char stack[<a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>]; <a name=L56 href="source/kernel/sched.c#L56">56</a> }; <a name=L57 href="source/kernel/sched.c#L57">57</a> <a name=L58 href="source/kernel/sched.c#L58">58</a> static union <a href="ident?i=task_union">task_union</a> <a href="ident?i=init_task">init_task</a> = {<a href="ident?i=INIT_TASK">INIT_TASK</a>,}; <a name=L59 href="source/kernel/sched.c#L59">59</a> <a name=L60 href="source/kernel/sched.c#L60">60</a> long volatile <a href="ident?i=jiffies">jiffies</a>=0; <a name=L61 href="source/kernel/sched.c#L61">61</a> long <a href="ident?i=startup_time">startup_time</a>=0; <a name=L62 href="source/kernel/sched.c#L62">62</a> struct <a href="ident?i=task_struct">task_struct</a> *<a href="ident?i=current">current</a> = &(<a href="ident?i=init_task">init_task</a>.<a href="ident?i=task">task</a>); <a name=L63 href="source/kernel/sched.c#L63">63</a> struct <a href="ident?i=task_struct">task_struct</a> *<a href="ident?i=last_task_used_math">last_task_used_math</a> = <a href="ident?i=NULL">NULL</a>; <a name=L64 href="source/kernel/sched.c#L64">64</a> <a name=L65 href="source/kernel/sched.c#L65">65</a> struct <a href="ident?i=task_struct">task_struct</a> * <a href="ident?i=task">task</a>[<a href="ident?i=NR_TASKS">NR_TASKS</a>] = {&(<a href="ident?i=init_task">init_task</a>.<a href="ident?i=task">task</a>), }; <a name=L66 href="source/kernel/sched.c#L66">66</a> <a name=L67 href="source/kernel/sched.c#L67">67</a> long <a href="ident?i=user_stack">user_stack</a> [ <a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>>>2 ] ; <a name=L68 href="source/kernel/sched.c#L68">68</a> <a name=L69 href="source/kernel/sched.c#L69">69</a> struct { <a name=L70 href="source/kernel/sched.c#L70">70</a> long * a; <a name=L71 href="source/kernel/sched.c#L71">71</a> short b; <a name=L72 href="source/kernel/sched.c#L72">72</a> } stack_start = { & <a href="ident?i=user_stack">user_stack</a> [<a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>>>2] , 0x10 }; <a name=L73 href="source/kernel/sched.c#L73">73</a> <b><i>/*</i></b> <a name=L74 href="source/kernel/sched.c#L74">74</a> <b><i> * 'math_state_restore()' saves the current math information in the</i></b> <a name=L75 href="source/kernel/sched.c#L75">75</a> <b><i> * old math state array, and gets the new ones from the current task</i></b> <a name=L76 href="source/kernel/sched.c#L76">76</a> <b><i> */</i></b> <a name=L77 href="source/kernel/sched.c#L77">77</a> void <a href="ident?i=math_state_restore">math_state_restore</a>() <a name=L78 href="source/kernel/sched.c#L78">78</a> { <a name=L79 href="source/kernel/sched.c#L79">79</a> if (<a href="ident?i=last_task_used_math">last_task_used_math</a> == <a href="ident?i=current">current</a>) <a name=L80 href="source/kernel/sched.c#L80">80</a> return; <a name=L81 href="source/kernel/sched.c#L81">81</a> __asm__(<i>"fwait"</i>); <a name=L82 href="source/kernel/sched.c#L82">82</a> if (<a href="ident?i=last_task_used_math">last_task_used_math</a>) { <a name=L83 href="source/kernel/sched.c#L83">83</a> __asm__(<i>"fnsave %0"</i>::<i>"m"</i> (<a href="ident?i=last_task_used_math">last_task_used_math</a>->tss.i387)); <a name=L84 href="source/kernel/sched.c#L84">84</a> } <a name=L85 href="source/kernel/sched.c#L85">85</a> <a href="ident?i=last_task_used_math">last_task_used_math</a>=<a href="ident?i=current">current</a>; <a name=L86 href="source/kernel/sched.c#L86">86</a> if (<a href="ident?i=current">current</a>->used_math) { <a name=L87 href="source/kernel/sched.c#L87">87</a> __asm__(<i>"frstor %0"</i>::<i>"m"</i> (<a href="ident?i=current">current</a>->tss.i387)); <a name=L88 href="source/kernel/sched.c#L88">88</a> } else { <a name=L89 href="source/kernel/sched.c#L89">89</a> __asm__(<i>"fninit"</i>::); <a name=L90 href="source/kernel/sched.c#L90">90</a> <a href="ident?i=current">current</a>->used_math=1; <a name=L91 href="source/kernel/sched.c#L91">91</a> } <a name=L92 href="source/kernel/sched.c#L92">92</a> } <a name=L93 href="source/kernel/sched.c#L93">93</a> <a name=L94 href="source/kernel/sched.c#L94">94</a> <b><i>/*</i></b> <a name=L95 href="source/kernel/sched.c#L95">95</a> <b><i> * 'schedule()' is the scheduler function. This is GOOD CODE! There</i></b> <a name=L96 href="source/kernel/sched.c#L96">96</a> <b><i> * probably won't be any reason to change this, as it should work well</i></b> <a name=L97 href="source/kernel/sched.c#L97">97</a> <b><i> * in all circumstances (ie gives IO-bound processes good response etc).</i></b> <a name=L98 href="source/kernel/sched.c#L98">98</a> <b><i> * The one thing you might take a look at is the signal-handler code here.</i></b> <a name=L99 href="source/kernel/sched.c#L99">99</a> <b><i> *</i></b><a name=L100 href="source/kernel/sched.c#L100">100</a> <b><i> * NOTE!! Task 0 is the 'idle' task, which gets called when no other</i></b><a name=L101 href="source/kernel/sched.c#L101">101</a> <b><i> * tasks can run. It can not be killed, and it cannot sleep. The 'state'</i></b><a name=L102 href="source/kernel/sched.c#L102">102</a> <b><i> * information in task[0] is never used.</i></b><a name=L103 href="source/kernel/sched.c#L103">103</a> <b><i> */</i></b><a name=L104 href="source/kernel/sched.c#L104">104</a> void <a href="ident?i=schedule">schedule</a>(void)<a name=L105 href="source/kernel/sched.c#L105">105</a> {<a name=L106 href="source/kernel/sched.c#L106">106</a> int i,next,c;<a name=L107 href="source/kernel/sched.c#L107">107</a> struct <a href="ident?i=task_struct">task_struct</a> ** p;<a name=L108 href="source/kernel/sched.c#L108">108</a> <a name=L109 href="source/kernel/sched.c#L109">109</a> <b><i>/* check alarm, wake up any interruptible tasks that have got a signal */</i></b><a name=L110 href="source/kernel/sched.c#L110">110</a> <a name=L111 href="source/kernel/sched.c#L111">111</a> for(p = &<a href="ident?i=LAST_TASK">LAST_TASK</a> ; p > &<a href="ident?i=FIRST_TASK">FIRST_TASK</a> ; --p)<a name=L112 href="source/kernel/sched.c#L112">112</a> if (*p) {<a name=L113 href="source/kernel/sched.c#L113">113</a> if ((*p)-><a href="ident?i=alarm">alarm</a> && (*p)-><a href="ident?i=alarm">alarm</a> < <a href="ident?i=jiffies">jiffies</a>) {<a name=L114 href="source/kernel/sched.c#L114">114</a> (*p)->signal |= (1<<(<a href="ident?i=SIGALRM">SIGALRM</a>-1));<a name=L115 href="source/kernel/sched.c#L115">115</a> (*p)-><a href="ident?i=alarm">alarm</a> = 0;<a name=L116 href="source/kernel/sched.c#L116">116</a> }<a name=L117 href="source/kernel/sched.c#L117">117</a> if (((*p)->signal & ~(<a href="ident?i=_BLOCKABLE">_BLOCKABLE</a> & (*p)->blocked)) &&<a name=L118 href="source/kernel/sched.c#L118">118</a> (*p)-><a href="ident?i=state">state</a>==<a href="ident?i=TASK_INTERRUPTIBLE">TASK_INTERRUPTIBLE</a>)<a name=L119 href="source/kernel/sched.c#L119">119</a> (*p)-><a href="ident?i=state">state</a>=<a href="ident?i=TASK_RUNNING">TASK_RUNNING</a>;<a name=L120 href="source/kernel/sched.c#L120">120</a> }<a name=L121 href="source/kernel/sched.c#L121">121</a> ⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -