{"id":112443,"date":"2026-10-03T16:56:55","date_gmt":"2026-10-03T08:56:55","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/112443.html"},"modified":"2026-10-03T16:56:55","modified_gmt":"2026-10-03T08:56:55","slug":"%e3%80%90linux%e4%b8%93%e6%a0%8f-03%e3%80%91%e8%bf%9b%e7%a8%8b%e7%ae%a1%e7%90%86%e4%b8%8e%e8%b0%83%e5%ba%a6","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/112443.html","title":{"rendered":"\u3010linux\u4e13\u680f 03\u3011\u8fdb\u7a0b\u7ba1\u7406\u4e0e\u8c03\u5ea6"},"content":{"rendered":"<p>\u672c\u7bc7\u5b9a\u4f4d:Linux \u5185\u6838\u7684&#034;\u5b87\u5b99\u4e2d\u5fc3&#034;\u662f task_struct\u2014\u2014\u6240\u6709\u5b50\u7cfb\u7edf\u90fd\u56f4\u7ed5\u5b83\u3002\u5bf9\u4e8e\u6709\u8fc7\u8f7b\u91cf\u7ea7\u5b9e\u65f6\u64cd\u4f5c\u7cfb\u7edf&#xff0c;\u5982FreeRTOS TCB \u5230 port \u5c42\u7ecf\u9a8c\u7684\u5de5\u7a0b\u5e08,\u672c\u7bc7\u628a&#034;Linux \u8fdb\u7a0b&#034;\u5bf9\u4f60 FreeRTOS \u4efb\u52a1\u7684\u589e\u91cf\u8bb2\u6e05:task_struct \u6bd4 TCB \u80d6\u5341\u500d(\u542b mm\/fs\/files\/signals)\u3001\u8c03\u5ea6\u4ece&#034;\u4f18\u5148\u7ea7\u62a2\u5360&#034;\u8df3\u5230&#034;CFS \u516c\u5e73 &#043; EEVDF&#034;\u3001\u4e0a\u4e0b\u6587\u5207\u6362\u4ece&#034;\u5207\u6808&#034;\u8df3\u5230&#034;\u5207\u5730\u5740\u7a7a\u95f4 &#043; \u5207\u6808 &#043; \u5207 fs\/files&#034;\u3002\u8bfb\u5b8c\u80fd\u5199\u5185\u6838\u7ebf\u7a0b\u3001\u80fd\u8c03\u8c03\u5ea6\u95ee\u9898\u3001\u80fd\u8bb2\u6e05 CFS vs FreeRTOS \u4f18\u5148\u7ea7\u8c03\u5ea6\u7684\u672c\u8d28\u5dee\u5f02\u3002<\/p>\n<hr \/>\n<h4>\u76ee\u5f55<\/h4>\n<ul>\n<li>\u4e00\u3001task_struct:\u5b87\u5b99\u4e2d\u5fc3\u7684\u6570\u636e\u7ed3\u6784<\/li>\n<li>\n<ul>\n<li>1.1 task_struct \u6709\u591a\u5927<\/li>\n<li>1.2 task_struct \u6838\u5fc3\u5b57\u6bb5(\u5206\u7ec4)<\/li>\n<li>1.3 \u5bf9\u7167 FreeRTOS TCB<\/li>\n<\/ul>\n<\/li>\n<li>\u4e8c\u3001\u8fdb\u7a0b\u72b6\u6001<\/li>\n<li>\n<ul>\n<li>2.1 Linux \u8fdb\u7a0b\u72b6\u6001<\/li>\n<li>2.2 \u72b6\u6001\u673a<\/li>\n<li>2.3 \u5173\u952e\u72b6\u6001\u89e3\u8bfb<\/li>\n<li>2.4 ps \u770b\u72b6\u6001<\/li>\n<li>2.5 \u5bf9\u7167 FreeRTOS \u72b6\u6001<\/li>\n<\/ul>\n<\/li>\n<li>\u4e09\u3001\u8fdb\u7a0b vs \u7ebf\u7a0b vs \u5185\u6838\u7ebf\u7a0b<\/li>\n<li>\n<ul>\n<li>3.1 Linux \u4e0d\u533a\u5206\u8fdb\u7a0b\u7ebf\u7a0b(\u90fd\u662f task_struct)<\/li>\n<li>3.2 fork \/ clone \/ vfork<\/li>\n<li>3.3 \u5185\u6838\u7ebf\u7a0b(kthread)<\/li>\n<li>3.4 PID vs TGID vs TID<\/li>\n<\/ul>\n<\/li>\n<li>\u56db\u3001\u4e0a\u4e0b\u6587\u5207\u6362(\u5bf9\u7167 RISC-V trap)<\/li>\n<li>\n<ul>\n<li>4.1 \u4e24\u79cd&#034;\u5207\u6362&#034;<\/li>\n<li>4.2 \u8fdb\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362\u505a\u4ec0\u4e48<\/li>\n<li>4.3 switch_to:\u5207\u5bc4\u5b58\u5668(\u67b6\u6784\u76f8\u5173)<\/li>\n<li>4.4 \u5bf9\u7167\u4f60 RISC-V trap \u5207\u6808<\/li>\n<li>4.5 \u4e3a\u4ec0\u4e48\u53ea\u5b58 callee-saved<\/li>\n<\/ul>\n<\/li>\n<li>\u4e94\u3001CFS \u8c03\u5ea6\u5668(Completely Fair Scheduler)\u2b50 \u6838\u5fc3<\/li>\n<li>\n<ul>\n<li>5.1 CFS \u7684\u6838\u5fc3\u601d\u60f3<\/li>\n<li>5.2 vruntime \u600e\u4e48\u7b97<\/li>\n<li>5.3 nice \u503c\u4e0e\u6743\u91cd<\/li>\n<li>5.4 CFS \u6570\u636e\u7ed3\u6784:\u7ea2\u9ed1\u6811<\/li>\n<li>5.5 \u8c03\u5ea6\u65f6\u5e8f<\/li>\n<li>5.6 sched_latency \u4e0e min_granularity<\/li>\n<li>5.7 \u5bf9\u7167 FreeRTOS \u4f18\u5148\u7ea7\u8c03\u5ea6<\/li>\n<\/ul>\n<\/li>\n<li>\u516d\u3001EEVDF(\u65b0\u8c03\u5ea6\u5668,Linux 6.6&#043;)<\/li>\n<li>\n<ul>\n<li>6.1 \u4e3a\u4ec0\u4e48 CFS \u5347\u7ea7\u5230 EEVDF<\/li>\n<li>6.2 EEVDF \u6838\u5fc3\u601d\u60f3<\/li>\n<li>6.3 \u5bf9\u4f60\u5f71\u54cd<\/li>\n<\/ul>\n<\/li>\n<li>\u4e03\u3001\u8c03\u5ea6\u7b56\u7565(Scheduling Policy)<\/li>\n<li>\n<ul>\n<li>7.1 \u4e09\u7c7b\u8c03\u5ea6\u7b56\u7565<\/li>\n<li>7.2 RT \u4f18\u5148\u7ea7<\/li>\n<li>7.3 chrt \u6539\u7b56\u7565<\/li>\n<li>7.4 SCHED_DEADLINE(\u786c\u5b9e\u65f6)<\/li>\n<\/ul>\n<\/li>\n<li>\u516b\u3001\u62a2\u5360(Preemption)<\/li>\n<li>\n<ul>\n<li>8.1 \u62a2\u5360\u70b9<\/li>\n<li>8.2 \u62a2\u5360\u7b49\u7ea7(CONFIG)<\/li>\n<li>8.3 \u5173\u62a2\u5360 vs \u5173\u4e2d\u65ad<\/li>\n<\/ul>\n<\/li>\n<li>\u4e5d\u3001fork \/ exec \/ wait(\u8fdb\u7a0b\u751f\u547d\u5468\u671f)<\/li>\n<li>\n<ul>\n<li>9.1 fork()<\/li>\n<li>9.2 exec()<\/li>\n<li>9.3 wait()<\/li>\n<li>9.4 \u5b64\u513f\u8fdb\u7a0b\u4e0e\u50f5\u5c38<\/li>\n<\/ul>\n<\/li>\n<li>\u5341\u3001\u8fdb\u7a0b\u5173\u7cfb\u4e0e\u4f1a\u8bdd<\/li>\n<li>\n<ul>\n<li>10.1 \u8fdb\u7a0b\u7ec4 \/ \u4f1a\u8bdd<\/li>\n<li>10.2 \u5b88\u62a4\u8fdb\u7a0b(daemon)<\/li>\n<\/ul>\n<\/li>\n<li>\u5341\u4e00\u3001\u5e38\u7528\u8fdb\u7a0b\u8c03\u8bd5<\/li>\n<li>\n<ul>\n<li>11.1 \u5de5\u5177<\/li>\n<li>11.2 \u5173\u952e \/proc \u5b57\u6bb5<\/li>\n<\/ul>\n<\/li>\n<li>\u5341\u4e8c\u3001\u672c\u7bc7\u5c0f\u7ed3<\/li>\n<li>\u901f\u67e5\u8868<\/li>\n<\/ul>\n<h2>\u4e00\u3001task_struct:\u5b87\u5b99\u4e2d\u5fc3\u7684\u6570\u636e\u7ed3\u6784<\/h2>\n<h3>1.1 task_struct \u6709\u591a\u5927<\/h3>\n<ul>\n<li>FreeRTOS TCB:\u51e0\u767e\u5b57\u8282(\u6808\u6307\u9488\/\u4f18\u5148\u7ea7\/\u72b6\u6001\/\u94fe\u8868\u8282\u70b9)<\/li>\n<li>Linux task_struct:\u7ea6 8000 \u5b57\u8282(ARM64\/RISC-V 64)<\/li>\n<\/ul>\n<p>\u4e3a\u4ec0\u4e48\u8fd9\u4e48\u5927?\u56e0\u4e3a Linux \u8fdb\u7a0b\u8981\u72ec\u7acb\u5730\u5740\u7a7a\u95f4 &#043; \u6587\u4ef6\u4e0a\u4e0b\u6587 &#043; \u4fe1\u53f7 &#043; cgroup &#043; namespace &#043; \u5ba1\u8ba1\u2026\u5168\u6302\u8fd9\u91cc\u3002<\/p>\n<h3>1.2 task_struct \u6838\u5fc3\u5b57\u6bb5(\u5206\u7ec4)<\/h3>\n<p><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u6807\u8bc6 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token class-name\">pid_t<\/span> pid<span class=\"token punctuation\">;<\/span>                  <span class=\"token comment\">\/\/ \u8fdb\u7a0b ID(\u7ebf\u7a0b\u7ec4\u91cc\u662f\u7ebf\u7a0b ID)<\/span><br \/>\n    <span class=\"token class-name\">pid_t<\/span> tgid<span class=\"token punctuation\">;<\/span>                 <span class=\"token comment\">\/\/ \u7ebf\u7a0b\u7ec4 ID(\u8fdb\u7a0b ID,\u7528\u6237\u770b\u5230\u7684)<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>group_leader<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u7ebf\u7a0b\u7ec4\u9996\u9886<\/span><br \/>\n    <span class=\"token keyword\">char<\/span> comm<span class=\"token punctuation\">[<\/span>TASK_COMM_LEN<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span>   <span class=\"token comment\">\/\/ \u53ef\u6267\u884c\u6587\u4ef6\u540d(16 \u5b57\u7b26)<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u72b6\u6001 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">volatile<\/span> <span class=\"token keyword\">long<\/span> state<span class=\"token punctuation\">;<\/span>        <span class=\"token comment\">\/\/ \u8fdb\u7a0b\u72b6\u6001(\u89c1 \u00a7\u4e8c)<\/span><br \/>\n    <span class=\"token keyword\">int<\/span> exit_state<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">int<\/span> prio<span class=\"token punctuation\">,<\/span> static_prio<span class=\"token punctuation\">,<\/span> normal_prio<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u4f18\u5148\u7ea7<\/span><br \/>\n    <span class=\"token keyword\">unsigned<\/span> <span class=\"token keyword\">int<\/span> policy<span class=\"token punctuation\">;<\/span>        <span class=\"token comment\">\/\/ \u8c03\u5ea6\u7b56\u7565(SCHED_NORMAL\/FIFO\/RR)<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u8c03\u5ea6 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">sched_class<\/span> <span class=\"token operator\">*<\/span>sched_class<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u8c03\u5ea6\u7c7b<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">sched_entity<\/span> se<span class=\"token punctuation\">;<\/span>     <span class=\"token comment\">\/\/ CFS \u8c03\u5ea6\u5b9e\u4f53(vruntime \u7b49)<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">sched_rt_entity<\/span> rt<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ RT \u8c03\u5ea6\u5b9e\u4f53<\/span><br \/>\n    <span class=\"token keyword\">unsigned<\/span> <span class=\"token keyword\">int<\/span> rt_priority<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token class-name\">cpumask_t<\/span> cpus_allowed<span class=\"token punctuation\">;<\/span>     <span class=\"token comment\">\/\/ \u5141\u8bb8\u8dd1\u7684 CPU<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u5bb6\u65cf &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>parent<span class=\"token punctuation\">;<\/span>      <span class=\"token comment\">\/\/ \u7236\u8fdb\u7a0b<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">list_head<\/span> children<span class=\"token punctuation\">;<\/span>       <span class=\"token comment\">\/\/ \u5b50\u8fdb\u7a0b\u94fe\u8868<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">list_head<\/span> sibling<span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u5185\u5b58(\u2605\u5bf9\u7167 FreeRTOS \u6700\u5927\u5dee\u5f02)&#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">mm_struct<\/span> <span class=\"token operator\">*<\/span>mm<span class=\"token punctuation\">;<\/span>       <span class=\"token comment\">\/\/ \u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4(\u7ebf\u7a0b\u5171\u4eab)<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">mm_struct<\/span> <span class=\"token operator\">*<\/span>active_mm<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5185\u6838\u7ebf\u7a0b\u7528(\u501f\u6765\u7684 mm)<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u6587\u4ef6 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">files_struct<\/span> <span class=\"token operator\">*<\/span>files<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u6253\u5f00\u7684\u6587\u4ef6\u8868<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">fs_struct<\/span> <span class=\"token operator\">*<\/span>fs<span class=\"token punctuation\">;<\/span>       <span class=\"token comment\">\/\/ \u6587\u4ef6\u7cfb\u7edf\u6839\/root<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u4fe1\u53f7 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">signal_struct<\/span> <span class=\"token operator\">*<\/span>signal<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">sighand_struct<\/span> <span class=\"token operator\">*<\/span>sighand<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token class-name\">sigset_t<\/span> blocked<span class=\"token punctuation\">,<\/span> real_blocked<span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u6808 &#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>stack<span class=\"token punctuation\">;<\/span>                <span class=\"token comment\">\/\/ \u5185\u6838\u6808(union with thread_info)<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; \u65f6\u95f4\u7edf\u8ba1 &#061;&#061;&#061;<\/span><br \/>\n    u64 utime<span class=\"token punctuation\">,<\/span> stime<span class=\"token punctuation\">;<\/span>           <span class=\"token comment\">\/\/ \u7528\u6237\u6001\/\u5185\u6838\u6001\u65f6\u95f4<\/span><br \/>\n    u64 nvcsw<span class=\"token punctuation\">,<\/span> nivcsw<span class=\"token punctuation\">;<\/span>          <span class=\"token comment\">\/\/ \u81ea\u613f\/\u975e\u81ea\u613f\u5207\u6362\u6b21\u6570<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#061;&#061;&#061; namespace\/cgroup(\u5bb9\u5668)&#061;&#061;&#061;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">nsproxy<\/span> <span class=\"token operator\">*<\/span>nsproxy<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">css_set<\/span> __rcu <span class=\"token operator\">*<\/span>cgroups<span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#8230; \u8fd8\u6709\u51e0\u767e\u4e2a\u5b57\u6bb5<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<h3>1.3 \u5bf9\u7167 FreeRTOS TCB<\/h3>\n<table>\n<tr>\u5b57\u6bb5FreeRTOS TCBLinux task_struct\u5dee\u5f02<\/tr>\n<tbody>\n<tr>\n<td>\u6808\u6307\u9488<\/td>\n<td>pxTopOfStack<\/td>\n<td>sp(\u5728 stack \u91cc)<\/td>\n<td>\u540c<\/td>\n<\/tr>\n<tr>\n<td>\u4f18\u5148\u7ea7<\/td>\n<td>uxPriority<\/td>\n<td>prio\/static_prio<\/td>\n<td>Linux \u66f4\u590d\u6742(\u591a\u5957)<\/td>\n<\/tr>\n<tr>\n<td>\u72b6\u6001<\/td>\n<td>eTaskState<\/td>\n<td>state<\/td>\n<td>Linux \u72b6\u6001\u66f4\u591a<\/td>\n<\/tr>\n<tr>\n<td>\u94fe\u8868<\/td>\n<td>xStateListItem \u7b49<\/td>\n<td>list_head \u591a\u4e2a<\/td>\n<td>\u540c\u601d\u8def<\/td>\n<\/tr>\n<tr>\n<td>\u5730\u5740\u7a7a\u95f4<\/td>\n<td>\u274c \u65e0<\/td>\n<td>mm_struct \u2605<\/td>\n<td>Linux \u6700\u5927\u589e\u91cf<\/td>\n<\/tr>\n<tr>\n<td>\u6587\u4ef6\u8868<\/td>\n<td>\u274c \u65e0<\/td>\n<td>files_struct \u2605<\/td>\n<td>Linux \u6700\u5927\u589e\u91cf<\/td>\n<\/tr>\n<tr>\n<td>\u4fe1\u53f7<\/td>\n<td>\u274c \u65e0<\/td>\n<td>signal\/sighand \u2605<\/td>\n<td>Linux \u6709<\/td>\n<\/tr>\n<tr>\n<td>\u65f6\u95f4\u7edf\u8ba1<\/td>\n<td>\u274c \u65e0<\/td>\n<td>utime\/stime<\/td>\n<td>Linux \u6709<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2: Linux task_struct \u662f&#034;\u80d6\u7248 TCB&#034;\u2014\u2014\u591a\u4e86 mm(\u5730\u5740\u7a7a\u95f4)\/files(\u6587\u4ef6)\/signals(\u4fe1\u53f7)\/namespace(\u5bb9\u5668)\u3002\u56e0\u4e3a Linux \u8fdb\u7a0b\u8981\u72ec\u7acb\u5730\u5740\u7a7a\u95f4\u548c\u6587\u4ef6\u4e0a\u4e0b\u6587,FreeRTOS \u4efb\u52a1\u5168\u5728\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\u5171\u4eab\u4e00\u5207\u3002\u5b57\u6bb5\u867d\u591a,\u6838\u5fc3\u601d\u8def\u540c(\u6807\u8bc6\/\u72b6\u6001\/\u8c03\u5ea6\/\u6808),\u589e\u91cf\u5728 mm \u548c files\u3002<\/p>\n<hr \/>\n<h2>\u4e8c\u3001\u8fdb\u7a0b\u72b6\u6001<\/h2>\n<h3>2.1 Linux \u8fdb\u7a0b\u72b6\u6001<\/h3>\n<p>#define TASK_RUNNING        0   \/\/ \u53ef\u8fd0\u884c(\u5c31\u7eea\u6216\u6b63\u5728\u8dd1)<br \/>\n#define TASK_INTERRUPTIBLE  1   \/\/ \u53ef\u4e2d\u65ad\u7761\u7720(\u4fe1\u53f7\u80fd\u5524\u9192)<br \/>\n#define TASK_UNINTERRUPTIBLE 2  \/\/ \u4e0d\u53ef\u4e2d\u65ad\u7761\u7720(\u4fe1\u53f7\u4e0d\u5524\u9192,\u7b49 IO)<br \/>\n#define __TASK_STOPPED      4   \/\/ \u505c\u6b62(\u4fe1\u53f7 SIGSTOP)<br \/>\n#define __TASK_TRACED      8   \/\/ \u88ab\u8ddf\u8e2a(gdb)<br \/>\n#define EXIT_ZOMBIE       16   \/\/ \u50f5\u5c38(\u6b7b\u4e86\u7b49\u7236\u6536\u5c38)<br \/>\n#define EXIT_DEAD         32   \/\/ \u6700\u7ec8\u6b7b\u4ea1<\/p>\n<h3>2.2 \u72b6\u6001\u673a<\/h3>\n<p>       fork()<br \/>\n         \u2502<br \/>\n         \u25bc<br \/>\n    \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510  \u8c03\u5ea6\u9009\u4e2d   \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510<br \/>\n    \u2502 RUNNING \u2502 \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500&gt; \u2502 RUNNING \u2502<br \/>\n    \u2502 (\u5c31\u7eea)  \u2502 &lt;\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 \u2502 (\u8fd0\u884c)  \u2502<br \/>\n    \u2514\u2500\u2500\u2500\u2500\u252c\u2500\u2500\u2500\u2500\u2518  \u65f6\u95f4\u7247\u5230   \u2514\u2500\u2500\u2500\u2500\u252c\u2500\u2500\u2500\u2500\u2518<br \/>\n         \u2502                        \u2502<br \/>\n         \u2502 \u7b49 IO\/\u4fe1\u53f7\u91cf           \u2502 \u4fe1\u53f7\/IO \u5b8c\u6210<br \/>\n         \u25bc                        \u25bc<br \/>\n    \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510         \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510<br \/>\n    \u2502INTERRUPTIBLE \u2502 \u2500\u2500\u2500\u2500\u2500\u2500\u2500&gt;\u2502 RUNNING \u2502<br \/>\n    \u2502 (\u53ef\u4e2d\u65ad\u7761)   \u2502  \u5524\u9192    \u2502 (\u5c31\u7eea)  \u2502<br \/>\n    \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518         \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518<br \/>\n         \u2502<br \/>\n         \u2502 \u7b49 \u78c1\u76d8 IO(D \u72b6\u6001)<br \/>\n         \u25bc<br \/>\n    \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510<br \/>\n    \u2502UNINTERRUPTIBLE \u2502  \u4fe1\u53f7\u5524\u4e0d\u9192,\u53ea\u80fd IO \u5b8c\u6210<br \/>\n    \u2502 (\u4e0d\u53ef\u4e2d\u65ad\u7761)   \u2502<br \/>\n    \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518<\/p>\n<h3>2.3 \u5173\u952e\u72b6\u6001\u89e3\u8bfb<\/h3>\n<ul>\n<li>TASK_RUNNING:\u5c31\u7eea(\u5728\u8fd0\u884c\u961f\u5217)\u6216\u6b63\u5728\u8dd1(\u5355 CPU \u540c\u65f6\u53ea\u6709\u4e00\u4e2a&#034;\u8dd1&#034;)<\/li>\n<li>TASK_INTERRUPTIBLE:\u53ef\u4e2d\u65ad\u7761\u7720,\u7b49\u4e8b\u4ef6(\u4fe1\u53f7\u91cf\/IO\/\u4fe1\u53f7),\u4fe1\u53f7\u80fd\u6253\u65ad<\/li>\n<li>TASK_UNINTERRUPTIBLE:D \u72b6\u6001,\u7b49\u78c1\u76d8 IO \u7b49,\u4fe1\u53f7\u5524\u4e0d\u9192\u2014\u2014\u8fd9\u662f&#034;\u6740\u4e0d\u6389&#034;\u7684\u8fdb\u7a0b(kill -9 \u4e5f\u6ca1\u7528)<\/li>\n<li>TASK_ZOMBIE:\u6b7b\u4e86\u4f46\u7236\u6ca1 wait(),\u5360 PID \u548c\u9000\u51fa\u7801,\u7b49\u6536\u5c38<\/li>\n<\/ul>\n<h3>2.4 ps \u770b\u72b6\u6001<\/h3>\n<p><span class=\"token function\">ps<\/span> <span class=\"token parameter variable\">-eo<\/span> pid,stat,comm<br \/>\n<span class=\"token comment\"># STAT \u5217:<\/span><br \/>\n<span class=\"token comment\"># R&#061;running  S&#061;interruptible sleep  D&#061;uninterruptible sleep<\/span><br \/>\n<span class=\"token comment\"># T&#061;stopped  Z&#061;zombie  X&#061;dead<\/span><br \/>\n<span class=\"token comment\"># &#043; \u524d\u53f0  s \u4f1a\u8bdd\u9996  l \u591a\u7ebf\u7a0b  &lt; \u9ad8\u4f18\u5148\u7ea7  N \u4f4e\u4f18\u5148\u7ea7<\/span><\/p>\n<h3>2.5 \u5bf9\u7167 FreeRTOS \u72b6\u6001<\/h3>\n<table>\n<tr>FreeRTOSLinux\u5dee\u5f02<\/tr>\n<tbody>\n<tr>\n<td>Running<\/td>\n<td>RUNNING(\u8fd0\u884c)<\/td>\n<td>\u540c<\/td>\n<\/tr>\n<tr>\n<td>Ready<\/td>\n<td>RUNNING(\u5c31\u7eea)<\/td>\n<td>Linux \u4e0d\u5206\u5c31\u7eea\/\u8fd0\u884c(\u90fd RUNNING)<\/td>\n<\/tr>\n<tr>\n<td>Blocked<\/td>\n<td>INTERRUPTIBLE\/UNINTERRUPTIBLE<\/td>\n<td>Linux \u5206\u4e24\u79cd\u7761\u7720<\/td>\n<\/tr>\n<tr>\n<td>Suspended<\/td>\n<td>STOPPED<\/td>\n<td>\u7c7b\u4f3c<\/td>\n<\/tr>\n<tr>\n<td>Deleted<\/td>\n<td>ZOMBIE<\/td>\n<td>Linux \u8981\u7236\u6536\u5c38<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>D \u72b6\u6001\u662f Linux \u7684&#034;\u6740\u4e0d\u6389&#034; FreeRTOS \u4efb\u52a1\u963b\u585e &#061; \u7b49 signal\/queue,\u80fd\u88ab\u5220\u3002Linux D \u72b6\u6001(\u7b49\u78c1\u76d8 IO)\u4fe1\u53f7\u5524\u4e0d\u9192,kill -9 \u4e5f\u6740\u4e0d\u6389\u2014\u2014\u56e0\u4e3a\u6740\u5b83\u8981\u5b83\u54cd\u5e94\u4fe1\u53f7,\u5b83\u5728 D \u4e0d\u54cd\u5e94\u3002\u8fd9\u662f Linux \u6bd4 FreeRTOS \u590d\u6742\u7684\u70b9:IO \u7b49\u5f85\u6709&#034;\u4e0d\u53ef\u6253\u65ad&#034;\u8bed\u4e49,\u9632\u6b62 IO \u4e2d\u9014\u88ab\u6253\u65ad\u5bfc\u81f4\u6570\u636e\u4e0d\u4e00\u81f4\u3002\u4f60\u8c03&#034;\u8fdb\u7a0b\u6740\u4e0d\u6389&#034;\u5148\u770b\u662f\u4e0d\u662f D \u72b6\u6001\u3002<\/p>\n<hr \/>\n<h2>\u4e09\u3001\u8fdb\u7a0b vs \u7ebf\u7a0b vs \u5185\u6838\u7ebf\u7a0b<\/h2>\n<h3>3.1 Linux \u4e0d\u533a\u5206\u8fdb\u7a0b\u7ebf\u7a0b(\u90fd\u662f task_struct)<\/h3>\n<table>\n<tr>\u6982\u5ff5mm \u662f\u5426\u5171\u4eabfiles \u662f\u5426\u5171\u4eab\u521b\u5efa\u65b9\u5f0f<\/tr>\n<tbody>\n<tr>\n<td>\u8fdb\u7a0b<\/td>\n<td>\u4e0d\u5171\u4eab(\u72ec\u7acb)<\/td>\n<td>\u4e0d\u5171\u4eab<\/td>\n<td>fork()<\/td>\n<\/tr>\n<tr>\n<td>\u7ebf\u7a0b<\/td>\n<td>\u5171\u4eab<\/td>\n<td>\u5171\u4eab<\/td>\n<td>clone(CLONE_VM|CLONE_FILES|\u2026)<\/td>\n<\/tr>\n<tr>\n<td>\u5185\u6838\u7ebf\u7a0b<\/td>\n<td>\u65e0 mm(\u501f active_mm)<\/td>\n<td>\u5171\u4eab init_files<\/td>\n<td>kthread_create()<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>3.2 fork \/ clone \/ vfork<\/h3>\n<p>Linux \u8fdb\u7a0b\u521b\u5efa\u5e95\u5c42\u90fd\u662f clone \u7cfb\u7edf\u8c03\u7528,\u9760 flag \u63a7\u5236\u5171\u4eab\u4ec0\u4e48:<\/p>\n<p><span class=\"token comment\">\/\/ fork:\u4e0d\u5171\u4eab(\u5b50\u72ec\u7acb)<\/span><br \/>\n<span class=\"token function\">clone<\/span><span class=\"token punctuation\">(<\/span>SIGCHLD<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ pthread_create:\u5171\u4eab mm\/files\/\u4fe1\u53f7\u7b49<\/span><br \/>\n<span class=\"token function\">clone<\/span><span class=\"token punctuation\">(<\/span>CLONE_VM <span class=\"token operator\">|<\/span> CLONE_FILES <span class=\"token operator\">|<\/span> CLONE_SIGHAND <span class=\"token operator\">|<\/span> CLONE_THREAD <span class=\"token operator\">|<\/span> <span class=\"token punctuation\">.<\/span><span class=\"token punctuation\">.<\/span><span class=\"token punctuation\">.<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ vfork:\u5171\u4eab mm,\u7236\u963b\u585e\u5230\u5b50 exec\/exit<\/span><br \/>\n<span class=\"token function\">clone<\/span><span class=\"token punctuation\">(<\/span>CLONE_VM <span class=\"token operator\">|<\/span> CLONE_VFORK<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<h3>3.3 \u5185\u6838\u7ebf\u7a0b(kthread)<\/h3>\n<p>\u5185\u6838\u7ebf\u7a0b:\u53ea\u5728\u5185\u6838\u6001\u8dd1,\u6ca1\u7528\u6237\u6001\u5730\u5740\u7a7a\u95f4\u3002\u7528\u9014:\u540e\u53f0\u6d3b(kworker\/ksoftirqd\/kthreadd\/migration)\u3002<\/p>\n<p><span class=\"token comment\">\/\/ \u521b\u5efa\u5185\u6838\u7ebf\u7a0b<\/span><br \/>\n<span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>k <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">kthread_create<\/span><span class=\"token punctuation\">(<\/span>my_thread_fn<span class=\"token punctuation\">,<\/span> arg<span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;mythread&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">wake_up_process<\/span><span class=\"token punctuation\">(<\/span>k<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u5524\u9192\u8ba9\u5b83\u8dd1<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u6216\u4e00\u6b65\u5230\u4f4d<\/span><br \/>\n<span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>k <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">kthread_run<\/span><span class=\"token punctuation\">(<\/span>my_thread_fn<span class=\"token punctuation\">,<\/span> arg<span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;mythread&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>\u5185\u6838\u7ebf\u7a0b\u7684 mm \u4e3a NULL,\u8dd1\u65f6 active_mm \u501f\u524d\u4e00\u4e2a\u8fdb\u7a0b\u7684 mm(\u7701\u5207\u9875\u8868)\u3002<\/p>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2:\u5185\u6838\u7ebf\u7a0b &#061; FreeRTOS \u4efb\u52a1 \u4f60 FreeRTOS \u4efb\u52a1 &#061; \u51fd\u6570\u6b7b\u5faa\u73af\u3002Linux \u5185\u6838\u7ebf\u7a0b\u6700\u50cf FreeRTOS \u4efb\u52a1\u2014\u2014\u4e00\u4e2a\u51fd\u6570\u5728\u5185\u6838\u6001\u5faa\u73af\u8dd1\u3002\u4f60\u5199\u9a71\u52a8\u8981\u540e\u53f0\u6d3b(\u8f6e\u8be2\/\u5904\u7406),\u7528 kthread_run \u8d77\u4e00\u4e2a,\u548c FreeRTOS xTaskCreate \u540c\u6784\u3002\u533a\u522b:\u5185\u6838\u7ebf\u7a0b\u5728\u5185\u6838\u6001(\u5168\u6743),FreeRTOS \u4efb\u52a1\u5728&#034;\u5185\u6838\u6001&#034;(FreeRTOS \u65e0\u5206\u5c42)\u3002\u7528\u6237\u6001\u7ebf\u7a0b( pthread)\u662f\u53e6\u4e00\u56de\u4e8b,\u5728 U \u6001\u8dd1\u3002<\/p>\n<h3>3.4 PID vs TGID vs TID<\/h3>\n<ul>\n<li>PID(Process ID):\u7528\u6237\u770b\u5230\u7684\u8fdb\u7a0b\u53f7,\u5b9e\u9645\u662f TGID(\u7ebf\u7a0b\u7ec4 ID)<\/li>\n<li>TID(Thread ID):\u7ebf\u7a0b ID,\u5185\u6838 task_struct-&gt;pid(\u6bcf\u4e2a task_struct \u552f\u4e00)<\/li>\n<li>\u5355\u7ebf\u7a0b\u8fdb\u7a0b:PID &#061;&#061; TID<\/li>\n<li>\u591a\u7ebf\u7a0b\u8fdb\u7a0b:\u540c\u7ec4 task_struct \u5171\u4eab TGID,\u5404 TID \u4e0d\u540c<\/li>\n<\/ul>\n<p><span class=\"token function\">ps<\/span> <span class=\"token parameter variable\">-eLf<\/span>   <span class=\"token comment\"># \u770b PID(&#061;TGID)\/ TID<\/span><br \/>\n<span class=\"token comment\"># \u591a\u7ebf\u7a0b\u8fdb\u7a0b:N \u884c\u540c PID,\u4e0d\u540c TID(LWP)<\/span><\/p>\n<hr \/>\n<h2>\u56db\u3001\u4e0a\u4e0b\u6587\u5207\u6362(\u5bf9\u7167 RISC-V trap)<\/h2>\n<h3>4.1 \u4e24\u79cd&#034;\u5207\u6362&#034;<\/h3>\n<table>\n<tr>\u5207\u6362\u662f\u4ec0\u4e48\u9891\u7387<\/tr>\n<tbody>\n<tr>\n<td>\u7528\u6237\u6001\u2194\u5185\u6838\u6001<\/td>\n<td>syscall\/\u4e2d\u65ad,\u540c\u8fdb\u7a0b\u5185<\/td>\n<td>\u9ad8(\u6bcf\u6b21 syscall)<\/td>\n<\/tr>\n<tr>\n<td>\u8fdb\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362<\/td>\n<td>\u4ece\u8fdb\u7a0b A \u5207\u5230\u8fdb\u7a0b B<\/td>\n<td>\u4e2d(\u8c03\u5ea6\u65f6)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>4.2 \u8fdb\u7a0b\u4e0a\u4e0b\u6587\u5207\u6362\u505a\u4ec0\u4e48<\/h3>\n<p>context_switch()(kernel\/sched\/core.c):<\/p>\n<p><span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">context_switch<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">rq<\/span> <span class=\"token operator\">*<\/span>rq<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>prev<span class=\"token punctuation\">,<\/span><br \/>\n                           <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">task_struct<\/span> <span class=\"token operator\">*<\/span>next<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">mm_struct<\/span> <span class=\"token operator\">*<\/span>mm <span class=\"token operator\">&#061;<\/span> next<span class=\"token operator\">-&gt;<\/span>mm<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">mm_struct<\/span> <span class=\"token operator\">*<\/span>oldmm <span class=\"token operator\">&#061;<\/span> prev<span class=\"token operator\">-&gt;<\/span>active_mm<span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ 1. \u5207\u5730\u5740\u7a7a\u95f4(\u82e5\u4e0d\u540c)<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">unlikely<\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span>mm<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>           <span class=\"token comment\">\/\/ next \u662f\u5185\u6838\u7ebf\u7a0b<\/span><br \/>\n        next<span class=\"token operator\">-&gt;<\/span>active_mm <span class=\"token operator\">&#061;<\/span> oldmm<span class=\"token punctuation\">;<\/span>   <span class=\"token comment\">\/\/ \u501f prev \u7684 mm<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>prev<span class=\"token operator\">-&gt;<\/span>mm <span class=\"token operator\">!&#061;<\/span> mm<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span>   <span class=\"token comment\">\/\/ \u4e0d\u540c\u8fdb\u7a0b<\/span><br \/>\n        <span class=\"token function\">switch_mm<\/span><span class=\"token punctuation\">(<\/span>oldmm<span class=\"token punctuation\">,<\/span> mm<span class=\"token punctuation\">,<\/span> next<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u5207\u9875\u8868(\u5199 satp &#043; flush TLB)<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ 2. \u5207\u5bc4\u5b58\u5668(\u6808\u6307\u9488\/ra\/&#8230;)-&gt; switch_to()<\/span><br \/>\n    <span class=\"token function\">switch_to<\/span><span class=\"token punctuation\">(<\/span>prev<span class=\"token punctuation\">,<\/span> next<span class=\"token punctuation\">,<\/span> prev<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<h3>4.3 switch_to:\u5207\u5bc4\u5b58\u5668(\u67b6\u6784\u76f8\u5173)<\/h3>\n<p>switch_to \u6700\u7ec8\u8c03 __switch_to(arch\/riscv\/kernel\/entry.S \u6216\u7c7b\u4f3c):<\/p>\n<p>\/\/ \u7b80\u5316\u7684 RISC-V \u7248<br \/>\n__switch_to:<br \/>\n    # 1. \u4fdd\u5b58 prev \u7684 callee-saved \u5bc4\u5b58\u5668\u5230 prev \u6808<br \/>\n    addi sp, sp, -FRAME<br \/>\n    sd ra,  0(sp)<br \/>\n    sd s0,  8(sp)<br \/>\n    sd s1,  16(sp)<br \/>\n    &#8230; # s2-s11<br \/>\n    sd sp, TASK_THREAD_SP(a0)   # \u5b58 prev-&gt;thread.sp<\/p>\n<p>    # 2. \u5207\u6808:\u52a0\u8f7d next \u7684 sp<br \/>\n    ld sp, TASK_THREAD_SP(a1)   # next-&gt;thread.sp<\/p>\n<p>    # 3. \u5207 TP(percpu \u6307\u9488)<br \/>\n    ld tp, TASK_THREAD_TP(a1)<\/p>\n<p>    # 4. \u5207 CSR(thread.fcsr \u6d6e\u70b9 CSR \u7b49)<br \/>\n    &#8230;<\/p>\n<p>    # 5. \u6062\u590d next \u7684 callee-saved<br \/>\n    ld s1, 16(sp)<br \/>\n    ld s0, 8(sp)<br \/>\n    ld ra, 0(sp)<br \/>\n    addi sp, sp, FRAME<\/p>\n<p>    ret   # \u8df3\u5230 next \u4e0a\u6b21\u88ab\u5207\u8d70\u7684\u5730\u65b9(ra)<\/p>\n<h3>4.4 \u5bf9\u7167\u4f60 RISC-V trap \u5207\u6808<\/h3>\n<table>\n<tr>\u4f60 mscratch \u5207\u6808(\u4e2d\u65ad\u6808)Linux switch_to(\u8fdb\u7a0b\u5207\u6362)<\/tr>\n<tbody>\n<tr>\n<td>\u89e6\u53d1<\/td>\n<td>\u4e2d\u65ad\/trap<\/td>\n<td>\u8c03\u5ea6\u5668\u51b3\u5b9a<\/td>\n<\/tr>\n<tr>\n<td>\u5207\u4ec0\u4e48<\/td>\n<td>sp(\u4e2d\u65ad\u6808\u2194\u4efb\u52a1\u6808)<\/td>\n<td>sp &#043; \u9875\u8868 &#043; percpu &#043; CSR<\/td>\n<\/tr>\n<tr>\n<td>\u4fdd\u5b58\u5565<\/td>\n<td>\u5168\u90e8\u901a\u7528\u5bc4\u5b58\u5668(\u4e2d\u65ad\u53ef\u80fd\u7834\u574f)<\/td>\n<td>\u53ea\u5b58 callee-saved(s0-s11\/ra)<\/td>\n<\/tr>\n<tr>\n<td>\u8fd4\u56de<\/td>\n<td>mret<\/td>\n<td>ret<\/td>\n<\/tr>\n<tr>\n<td>\u9891\u7387<\/td>\n<td>\u6bcf\u6b21\u4e2d\u65ad<\/td>\n<td>\u6bcf\u6b21\u8c03\u5ea6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u4f60\u7684 mscratch \u5207\u6808\u662f Linux switch_to \u7684\u7b80\u5316\u7248 \u4f60 [[04-trap \u673a\u5236\u8be6\u89e3]] \u7684 mscratch \u5207\u6808:trap \u65f6 swap sp \u548c mscratch\u3002Linux switch_to \u540c\u6784\u2014\u2014\u5207 prev\/next \u7684 sp\u3002\u589e\u91cf\u662f:\u2460 \u8fd8\u5207\u9875\u8868(mm);\u2461 \u53ea\u5b58 callee-saved(\u8c03\u5ea6\u70b9\u5df2\u77e5 caller-saved \u4e0d\u91cd\u8981);\u2462 \u8fd8\u5207 percpu(tp)\u3002\u4f60\u5df2\u7ecf\u61c2&#034;\u5207\u6808&#034;,Linux \u662f\u653e\u5927\u7248,\u52a0\u4e86\u5207\u5730\u5740\u7a7a\u95f4\u3002<\/p>\n<h3>4.5 \u4e3a\u4ec0\u4e48\u53ea\u5b58 callee-saved<\/h3>\n<p>\u8c03\u5ea6\u70b9\u662f\u81ea\u613f\u7684(\u8c03\u5ea6\u5668\u5728\u660e\u786e\u4f4d\u7f6e\u8c03\u7528 schedule),\u4e0d\u662f\u4e2d\u65ad\u6253\u65ad\u3002\u6240\u4ee5\u8c03\u5ea6\u70b9\u4e4b\u540e,\u7f16\u8bd1\u5668\u53ea\u4fdd\u8bc1 callee-saved \u5bc4\u5b58\u5668(s0-s11\/ra\/sp)\u8de8\u51fd\u6570\u8c03\u7528\u4fdd\u7559,caller-saved(t0-t6\/a0-a7)\u7f16\u8bd1\u5668\u5df2\u5904\u7406\u3002\u53ea\u5b58 callee-saved \u8db3\u591f\u2014\u2014\u6bd4\u4e2d\u65ad\u4fdd\u5b58\u5168\u90e8\u5bc4\u5b58\u5668\u7701\u3002<\/p>\n<hr \/>\n<h2>\u4e94\u3001CFS \u8c03\u5ea6\u5668(Completely Fair Scheduler)\u2b50 \u6838\u5fc3<\/h2>\n<h3>5.1 CFS \u7684\u6838\u5fc3\u601d\u60f3<\/h3>\n<p>\u4e0d\u662f\u6309\u4f18\u5148\u7ea7\u62a2,\u662f\u6309&#034;\u8c01\u8dd1\u5f97\u5c11&#034;\u8f6e\u3002<\/p>\n<ul>\n<li>\u6bcf\u4e2a\u8fdb\u7a0b\u6709 vruntime(\u865a\u62df\u8fd0\u884c\u65f6\u95f4):\u8868\u793a\u5b83&#034;\u5df2\u7ecf\u8dd1\u4e86\u591a\u5c11&#034;<\/li>\n<li>\u8c03\u5ea6\u5668\u9009 vruntime \u6700\u5c0f\u7684\u8dd1(\u8dd1\u5f97\u6700\u5c11\u7684\u4f18\u5148)<\/li>\n<li>\u8dd1\u4e00\u4f1a\u513f,vruntime \u589e\u52a0,\u53d8\u6210\u4e0d\u662f\u6700\u5c0f,\u6362\u522b\u4eba\u8dd1<\/li>\n<li>\u7ed3\u679c:\u6bcf\u4e2a\u8fdb\u7a0b\u516c\u5e73\u5206\u4eab CPU<\/li>\n<\/ul>\n<h3>5.2 vruntime \u600e\u4e48\u7b97<\/h3>\n<p>vruntime &#043;&#061; \u5b9e\u9645\u8fd0\u884c\u65f6\u95f4 \u00d7 (NICE_0_LOAD \/ \u8fdb\u7a0b\u6743\u91cd)<\/p>\n<ul>\n<li>\u6743\u91cd(weight):\u7531 nice \u503c\u7b97\u51fa,nice 0 \u6743\u91cd 1024,nice -1 \u6743\u91cd 1171(\u9ad8 10%),nice &#043;1 \u6743\u91cd 920(\u4f4e 10%)<\/li>\n<li>\u9ad8\u6743\u91cd\u8fdb\u7a0b(nice \u4f4e):vruntime \u589e\u957f\u6162 \u2192 \u66f4\u4e45\u4fdd\u6301&#034;\u8dd1\u5f97\u5c11&#034; \u2192 \u66f4\u591a CPU<\/li>\n<li>\u4f4e\u6743\u91cd\u8fdb\u7a0b(nice \u9ad8):vruntime \u589e\u957f\u5feb \u2192 \u5f88\u5feb\u88ab\u6362\u4e0b \u2192 \u5c11 CPU<\/li>\n<\/ul>\n<h3>5.3 nice \u503c\u4e0e\u6743\u91cd<\/h3>\n<table>\n<tr>nice\u6743\u91cdCPU \u5360\u6bd4(nice 0 \u4e3a\u57fa\u51c6)<\/tr>\n<tbody>\n<tr>\n<td>-20<\/td>\n<td>88761<\/td>\n<td>\u6781\u9ad8<\/td>\n<\/tr>\n<tr>\n<td>-10<\/td>\n<td>9548<\/td>\n<td>~10x<\/td>\n<\/tr>\n<tr>\n<td>0<\/td>\n<td>1024<\/td>\n<td>1x(\u57fa\u51c6)<\/td>\n<\/tr>\n<tr>\n<td>&#043;10<\/td>\n<td>110<\/td>\n<td>~0.1x<\/td>\n<\/tr>\n<tr>\n<td>&#043;19<\/td>\n<td>15<\/td>\n<td>\u6781\u4f4e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li>nice \u8303\u56f4 -20 ~ &#043;19,\u9ed8\u8ba4 0<\/li>\n<li>nice \u4e0d\u662f\u4f18\u5148\u7ea7,\u662f\u6743\u91cd\u2014\u2014\u5f71\u54cd vruntime \u589e\u957f\u7387,\u8fdb\u800c\u5f71\u54cd CPU \u4efd\u989d<\/li>\n<li>\u666e\u901a\u7528\u6237\u53ea\u80fd\u8c03\u9ad8 nice(\u964d\u6743),root \u80fd\u8c03\u4f4e(\u5347\u6743)<\/li>\n<\/ul>\n<h3>5.4 CFS \u6570\u636e\u7ed3\u6784:\u7ea2\u9ed1\u6811<\/h3>\n<ul>\n<li>\u6bcf\u4e2a CPU \u4e00\u4e2a\u8fd0\u884c\u961f\u5217 struct rq<\/li>\n<li>CFS \u90e8\u5206\u7528\u7ea2\u9ed1\u6811(rbtree),\u6309 vruntime \u6392\u5e8f<\/li>\n<li>\u6700\u5de6\u8282\u70b9 &#061; vruntime \u6700\u5c0f &#061; \u4e0b\u4e00\u4e2a\u8dd1<\/li>\n<li>\u8fdb\u7a0b\u5165\u961f:\u63d2\u5165\u7ea2\u9ed1\u6811(O(log n))<\/li>\n<li>\u8fdb\u7a0b\u51fa\u961f:\u53d6\u6700\u5de6(O(log n))<\/li>\n<\/ul>\n<p>        CPU0 rq.cfs<br \/>\n            \u2502<br \/>\n         \u7ea2\u9ed1\u6811(\u6309 vruntime)<br \/>\n            \u2502<br \/>\n      [vruntime&#061;100] \u2190 \u6700\u5de6,\u4e0b\u4e00\u4e2a\u8dd1<br \/>\n       \/          \\\\<br \/>\n   [200]        [150]<br \/>\n    \/ \\\\          \/<br \/>\n [180][210]  [130]<\/p>\n<h3>5.5 \u8c03\u5ea6\u65f6\u5e8f<\/h3>\n<p>1. tick \u4e2d\u65ad \u2192 scheduler_tick()<br \/>\n2. \u5f53\u524d\u8fdb\u7a0b vruntime \u66f4\u65b0<br \/>\n3. \u68c0\u67e5:\u5f53\u524d vruntime \u662f\u5426 &gt; \u7ea2\u9ed1\u6811\u6700\u5de6 &#043; sched_latency?<br \/>\n   &#8211; \u5426:\u7ee7\u7eed\u8dd1<br \/>\n   &#8211; \u662f:\u8bbe need_resched,\u7a0d\u540e schedule()<br \/>\n4. schedule():<br \/>\n   &#8211; \u5f53\u524d\u8fdb\u7a0b\u5165\u961f(\u56de\u7ea2\u9ed1\u6811)<br \/>\n   &#8211; \u53d6\u6700\u5de6 &#061; next<br \/>\n   &#8211; context_switch(prev, next)<\/p>\n<h3>5.6 sched_latency \u4e0e min_granularity<\/h3>\n<ul>\n<li>sched_latency(\u76ee\u6807\u5ef6\u8fdf,~6ms):\u5728\u8fd9\u4e2a\u7a97\u53e3\u5185,\u6240\u6709\u8fdb\u7a0b\u90fd\u5e94\u8dd1\u4e00\u904d<\/li>\n<li>min_granularity(\u6700\u5c0f\u7c92\u5ea6,~0.75ms):\u6bcf\u4e2a\u8fdb\u7a0b\u81f3\u5c11\u8dd1\u8fd9\u4e48\u4e45,\u907f\u514d\u9891\u7e41\u5207\u6362<\/li>\n<li>\u65f6\u95f4\u7247 &#061; sched_latency \/ \u8fdb\u7a0b\u6570,\u4f46\u4e0d\u5c0f\u4e8e min_granularity<\/li>\n<\/ul>\n<p>4 \u4e2a\u8fdb\u7a0b,sched_latency&#061;6ms:<br \/>\n  \u6bcf\u4e2a\u65f6\u95f4\u7247 &#061; 6ms \/ 4 &#061; 1.5ms(&gt; min_granularity 0.75ms,OK)<br \/>\n  \u6bcf 6ms \u6bcf\u8fdb\u7a0b\u8dd1 1.5ms,\u516c\u5e73<\/p>\n<h3>5.7 \u5bf9\u7167 FreeRTOS \u4f18\u5148\u7ea7\u8c03\u5ea6<\/h3>\n<table>\n<tr>FreeRTOS \u4f18\u5148\u7ea7\u62a2\u5360Linux CFS<\/tr>\n<tbody>\n<tr>\n<td>\u9009\u8c01\u8dd1<\/td>\n<td>\u6700\u9ad8\u4f18\u5148\u7ea7<\/td>\n<td>vruntime \u6700\u5c0f<\/td>\n<\/tr>\n<tr>\n<td>\u540c\u4f18\u5148\u7ea7<\/td>\n<td>\u8f6e\u8f6c(time slicing)<\/td>\n<td>\u81ea\u7136\u516c\u5e73(vruntime \u8d8b\u540c)<\/td>\n<\/tr>\n<tr>\n<td>\u9ad8\u4f18\u5148\u7ea7<\/td>\n<td>\u62a2\u5360\u4f4e\u4f18\u5148\u7ea7(\u53ef\u80fd\u997f\u6b7b\u4f4e)<\/td>\n<td>\u6743\u91cd\u9ad8 CPU \u591a,\u4f46\u4e0d\u997f\u6b7b<\/td>\n<\/tr>\n<tr>\n<td>\u9965\u997f<\/td>\n<td>\u4f4e\u4f18\u5148\u7ea7\u53ef\u80fd\u997f\u6b7b<\/td>\n<td>\u4e0d\u4f1a(\u90fd\u8dd1)<\/td>\n<\/tr>\n<tr>\n<td>\u5b9e\u65f6\u6027<\/td>\n<td>\u9ad8(\u4f18\u5148\u7ea7\u7edd\u5bf9)<\/td>\n<td>\u4f4e(\u516c\u5e73,\u5ef6\u8fdf\u4e0d\u5b9a)<\/td>\n<\/tr>\n<tr>\n<td>\u9002\u5408<\/td>\n<td>\u5b9e\u65f6\u63a7\u5236<\/td>\n<td>\u4ea4\u4e92\/\u541e\u5410<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>CFS \u4e0d\u4f1a\u997f\u6b7b\u8fdb\u7a0b,\u4f46\u5b9e\u65f6\u6027\u5f31 FreeRTOS \u9ad8\u4f18\u5148\u7ea7\u4efb\u52a1\u6c38\u8fdc\u5148\u8dd1,\u4f4e\u4f18\u5148\u7ea7\u53ef\u80fd\u997f\u6b7b\u2014\u2014\u5bf9\u5b9e\u65f6\u63a7\u5236\u662f\u4f18\u70b9(\u5173\u952e\u4efb\u52a1\u5fc5\u987b\u5148\u8dd1)\u3002CFS \u4e0d\u8ba9\u4efb\u4f55\u8fdb\u7a0b\u997f\u6b7b\u2014\u2014\u5bf9\u4ea4\u4e92\/\u541e\u5410\u662f\u4f18\u70b9(\u90fd\u54cd\u5e94),\u4f46\u5b9e\u65f6\u6027\u5f31\u3002Linux \u5b9e\u65f6\u9700\u6c42\u7528 SCHED_FIFO\/RR(\u89c1 \u00a7\u516d),\u6216 RT-Linux \u8865\u4e01\u3002\u8fd9\u662f\u4f60 MCU \u8f6c Linux \u8981\u9002\u5e94\u7684:Linux \u9ed8\u8ba4\u4e0d\u786c\u5b9e\u65f6\u3002<\/p>\n<hr \/>\n<h2>\u516d\u3001EEVDF(\u65b0\u8c03\u5ea6\u5668,Linux 6.6&#043;)<\/h2>\n<h3>6.1 \u4e3a\u4ec0\u4e48 CFS \u5347\u7ea7\u5230 EEVDF<\/h3>\n<p>CFS \u7528\u4e86\u5341\u51e0\u5e74,\u95ee\u9898:<\/p>\n<ul>\n<li>\u516c\u5e73\u6027\u5728\u67d0\u4e9b\u573a\u666f\u4e0d\u5b8c\u7f8e(\u7279\u522b\u662f\u5ef6\u8fdf\u654f\u611f\u4efb\u52a1)<\/li>\n<li>\u542f\u53d1\u5f0f\u591a,\u96be\u8c03<\/li>\n<\/ul>\n<p>EEVDF(Earliest Eligible Virtual Deadline First)\u662f 6.6 \u5f15\u5165\u7684\u65b0\u7b97\u6cd5,\u7406\u8bba\u66f4\u624e\u5b9e\u3002<\/p>\n<h3>6.2 EEVDF \u6838\u5fc3\u601d\u60f3<\/h3>\n<ul>\n<li>\u6bcf\u4e2a\u8fdb\u7a0b\u6709 lag(\u6ede\u540e\u91cf):\u5e94\u5f97 CPU &#8211; \u5b9e\u5f97 CPU<\/li>\n<li>Eligible(\u5408\u683c):lag \u2264 0(\u6ca1\u591a\u5360)\u7684\u8fdb\u7a0b\u624d\u80fd\u8dd1<\/li>\n<li>\u5728\u5408\u683c\u8fdb\u7a0b\u91cc,\u9009 \u865a\u62df\u622a\u6b62\u65f6\u95f4(vdeadline) \u6700\u65e9\u7684\u8dd1<\/li>\n<li>\u7ed3\u679c:\u6bd4 CFS \u66f4\u7cbe\u786e\u7684\u516c\u5e73 &#043; \u66f4\u597d\u7684\u5ef6\u8fdf\u63a7\u5236<\/li>\n<\/ul>\n<h3>6.3 \u5bf9\u4f60\u5f71\u54cd<\/h3>\n<ul>\n<li>\u63a5\u53e3\u4e0d\u53d8(\u8fd8\u662f nice\/policy)<\/li>\n<li>\u884c\u4e3a\u66f4\u516c\u5e73,\u5ef6\u8fdf\u654f\u611f\u4efb\u52a1\u54cd\u5e94\u66f4\u597d<\/li>\n<li>\u4f60\u770b 6.6&#043; \u5185\u6838\u4ee3\u7801,kernel\/sched\/fair.c \u662f EEVDF \u5b9e\u73b0\u4e86<\/li>\n<\/ul>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2:EEVDF \u662f CFS \u7684\u6f14\u8fdb,\u4e0d\u662f\u9769\u547d CFS \u2192 EEVDF \u2014\u2014\u6838\u5fc3\u601d\u8def(\u516c\u5e73\/vruntime)\u4fdd\u7559,\u673a\u5236\u4f18\u5316(\u52a0 lag\/vdeadline)\u3002<\/p>\n<hr \/>\n<h2>\u4e03\u3001\u8c03\u5ea6\u7b56\u7565(Scheduling Policy)<\/h2>\n<h3>7.1 \u4e09\u7c7b\u8c03\u5ea6\u7b56\u7565<\/h3>\n<table>\n<tr>\u7b56\u7565\u8c03\u5ea6\u7c7b\u9002\u5408\u884c\u4e3a<\/tr>\n<tbody>\n<tr>\n<td>SCHED_NORMAL(SCHED_OTHER)<\/td>\n<td>CFS\/EEVDF<\/td>\n<td>\u666e\u901a\u8fdb\u7a0b<\/td>\n<td>\u516c\u5e73\u8c03\u5ea6,nice \u52a0\u6743<\/td>\n<\/tr>\n<tr>\n<td>SCHED_BATCH<\/td>\n<td>CFS\/EEVDF<\/td>\n<td>\u6279\u5904\u7406<\/td>\n<td>CPU \u5bc6\u96c6,\u5c11\u4ea4\u4e92,\u964d\u4f18\u5148\u7ea7<\/td>\n<\/tr>\n<tr>\n<td>SCHED_IDLE<\/td>\n<td>CFS\/EEVDF<\/td>\n<td>\u6781\u4f4e\u4f18\u5148\u7ea7<\/td>\n<td>\u53ea\u5728\u7a7a\u95f2\u8dd1(nice \u6bd4\u6240\u6709\u90fd\u4f4e)<\/td>\n<\/tr>\n<tr>\n<td>SCHED_FIFO<\/td>\n<td>RT<\/td>\n<td>\u5b9e\u65f6<\/td>\n<td>\u4f18\u5148\u7ea7\u62a2\u5360,\u65e0\u65f6\u95f4\u7247,\u8dd1\u5230\u8ba9\/\u963b\u585e<\/td>\n<\/tr>\n<tr>\n<td>SCHED_RR<\/td>\n<td>RT<\/td>\n<td>\u5b9e\u65f6<\/td>\n<td>\u4f18\u5148\u7ea7\u62a2\u5360 &#043; \u540c\u4f18\u5148\u7ea7\u8f6e\u8f6c<\/td>\n<\/tr>\n<tr>\n<td>SCHED_DEADLINE<\/td>\n<td>DL<\/td>\n<td>\u786c\u5b9e\u65f6<\/td>\n<td>EDF(\u6700\u65e9\u622a\u6b62\u671f\u4f18\u5148),\u6307\u5b9a\u5468\u671f\/\u8fd0\u884c\u65f6\u95f4\/\u622a\u6b62\u671f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>7.2 RT \u4f18\u5148\u7ea7<\/h3>\n<ul>\n<li>RT \u4f18\u5148\u7ea7\u8303\u56f4 1-99(99 \u6700\u9ad8)<\/li>\n<li>RT \u4f18\u5148\u7ea7 &gt; \u666e\u901a\u8fdb\u7a0b(\u4efb\u4f55 RT \u90fd\u62a2\u666e\u901a)<\/li>\n<li>SCHED_FIFO\/RR \u7684\u4f18\u5148\u7ea7 &#061; rt_priority<\/li>\n<li>RT \u8fdb\u7a0b\u80fd\u997f\u6b7b\u666e\u901a\u8fdb\u7a0b(\u5168\u5360 CPU)\u2192 \u5185\u6838\u6709 rt_throttling \u9ed8\u8ba4\u8ba9 RT \u6700\u591a\u5360 95%,\u7559 5% \u7ed9\u666e\u901a<\/li>\n<\/ul>\n<h3>7.3 chrt \u6539\u7b56\u7565<\/h3>\n<p>chrt <span class=\"token parameter variable\">-f<\/span> <span class=\"token number\">80<\/span> .\/my_realtime_app   <span class=\"token comment\"># SCHED_FIFO \u4f18\u5148\u7ea7 80<\/span><br \/>\nchrt <span class=\"token parameter variable\">-r<\/span> <span class=\"token number\">50<\/span> .\/my_rr_app          <span class=\"token comment\"># SCHED_RR \u4f18\u5148\u7ea7 50<\/span><br \/>\nchrt <span class=\"token parameter variable\">-o<\/span> <span class=\"token number\">0<\/span> .\/my_normal_app       <span class=\"token comment\"># SCHED_OTHER<\/span><br \/>\nchrt <span class=\"token parameter variable\">-p<\/span> <span class=\"token variable\"><span class=\"token variable\">$(<\/span>pidof myapp<span class=\"token variable\">)<\/span><\/span>          <span class=\"token comment\"># \u67e5\u770b\u7b56\u7565<\/span><\/p>\n<h3>7.4 SCHED_DEADLINE(\u786c\u5b9e\u65f6)<\/h3>\n<p><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">sched_attr<\/span> attr <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token punctuation\">.<\/span>size <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">sizeof<\/span><span class=\"token punctuation\">(<\/span>attr<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span><br \/>\n    <span class=\"token punctuation\">.<\/span>sched_policy <span class=\"token operator\">&#061;<\/span> SCHED_DEADLINE<span class=\"token punctuation\">,<\/span><br \/>\n    <span class=\"token punctuation\">.<\/span>sched_runtime <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">10000000<\/span><span class=\"token punctuation\">,<\/span>   <span class=\"token comment\">\/\/ \u6bcf\u5468\u671f\u9700 10ms<\/span><br \/>\n    <span class=\"token punctuation\">.<\/span>sched_period <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">100000000<\/span><span class=\"token punctuation\">,<\/span>   <span class=\"token comment\">\/\/ \u5468\u671f 100ms<\/span><br \/>\n    <span class=\"token punctuation\">.<\/span>sched_deadline <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">20000000<\/span><span class=\"token punctuation\">,<\/span>  <span class=\"token comment\">\/\/ \u622a\u6b62\u671f 20ms<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">sched_setattr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>attr<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<ul>\n<li>\u5185\u6838\u4fdd\u8bc1\u6bcf period \u5185\u7ed9 runtime,\u5728 deadline \u524d\u5b8c\u6210<\/li>\n<li>\u7528 EDF \u7b97\u6cd5\u8c03\u5ea6<\/li>\n<li>\u6bd4 FIFO\/RR \u66f4\u7cbe\u786e\u7684\u5b9e\u65f6\u4fdd\u8bc1<\/li>\n<\/ul>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2:Linux \u5b9e\u65f6\u6027 FreeRTOS \u662f\u786c\u5b9e\u65f6(\u4f18\u5148\u7ea7\u62a2\u5360,us \u7ea7\u54cd\u5e94)\u3002Linux \u9ed8\u8ba4(SCHED_NORMAL)\u4e0d\u662f\u5b9e\u65f6,ms \u7ea7\u5ef6\u8fdf\u3002\u8981\u7528 Linux \u505a\u5b9e\u65f6:<\/p>\n<ul>\n<li>SCHED_FIFO\/RR:\u5185\u6838\u62a2\u5360,\u8f6f\u5b9e\u65f6,\u4f46\u53ef\u80fd\u88ab\u4e2d\u65ad\/\u9a71\u52a8\u963b\u585e<\/li>\n<li>SCHED_DEADLINE:\u66f4\u7cbe\u786e,\u4f46\u4ecd\u975e\u786c\u5b9e\u65f6<\/li>\n<li>PREEMPT_RT \u8865\u4e01(\u4e3b\u7ebf\u5316\u4e2d):\u5168\u5185\u6838\u62a2\u5360,\u63a5\u8fd1\u786c\u5b9e\u65f6<\/li>\n<li>Xenomai:\u53cc\u6838(Linux &#043; \u5b9e\u65f6\u6838),\u786c\u5b9e\u65f6 \u8fb9\u7f18 AI\/\u63a7\u5236\u82e5\u8981\u786c\u5b9e\u65f6,\u9009 PREEMPT_RT \u6216 Xenomai\u3002<\/li>\n<\/ul>\n<hr \/>\n<h2>\u516b\u3001\u62a2\u5360(Preemption)<\/h2>\n<h3>8.1 \u62a2\u5360\u70b9<\/h3>\n<p>Linux \u5185\u6838\u53ef\u62a2\u5360(CONFIG_PREEMPT),\u5728\u5b89\u5168\u70b9\u68c0\u67e5 need_resched,\u8c03 schedule():<\/p>\n<table>\n<tr>\u62a2\u5360\u70b9\u4f55\u65f6<\/tr>\n<tbody>\n<tr>\n<td>\u4e2d\u65ad\u8fd4\u56de\u5185\u6838\u6001<\/td>\n<td>IRQ \u8fd4\u56de,\u68c0\u67e5 need_resched<\/td>\n<\/tr>\n<tr>\n<td>\u7cfb\u7edf\u8c03\u7528\u8fd4\u56de<\/td>\n<td>syscall \u8fd4\u56de\u7528\u6237\u6001\u524d<\/td>\n<\/tr>\n<tr>\n<td>\u663e\u5f0f schedule()<\/td>\n<td>\u4e3b\u52a8\u7761\u7720\/\u963b\u585e<\/td>\n<\/tr>\n<tr>\n<td>preempt_enable() \u540e<\/td>\n<td>\u4e34\u754c\u533a\u9000\u51fa<\/td>\n<\/tr>\n<tr>\n<td>\u4e92\u65a5\u9501\u91ca\u653e<\/td>\n<td>mutex_unlock \u540e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>8.2 \u62a2\u5360\u7b49\u7ea7(CONFIG)<\/h3>\n<table>\n<tr>\u914d\u7f6e\u62a2\u5360\u6027\u7528\u9014<\/tr>\n<tbody>\n<tr>\n<td>PREEMPT_NONE<\/td>\n<td>\u4e0d\u62a2\u5360(\u9664\u975e\u963b\u585e)<\/td>\n<td>\u670d\u52a1\u5668(\u541e\u5410)<\/td>\n<\/tr>\n<tr>\n<td>PREEMPT_VOLUNTARY<\/td>\n<td>\u81ea\u613f\u62a2\u5360(\u663e\u5f0f\u70b9)<\/td>\n<td>\u684c\u9762(\u5e73\u8861)<\/td>\n<\/tr>\n<tr>\n<td>PREEMPT<\/td>\n<td>\u5168\u5185\u6838\u62a2\u5360<\/td>\n<td>\u4f4e\u5ef6\u8fdf(\u5d4c\u5165\u5f0f\/\u684c\u9762)<\/td>\n<\/tr>\n<tr>\n<td>PREEMPT_RT<\/td>\n<td>\u5b9e\u65f6(\u51e0\u4e4e\u5168\u53ef\u62a2\u5360)<\/td>\n<td>\u786c\u5b9e\u65f6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>8.3 \u5173\u62a2\u5360 vs \u5173\u4e2d\u65ad<\/h3>\n<p><span class=\"token function\">preempt_disable<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>      <span class=\"token comment\">\/\/ \u5173\u62a2\u5360(\u672c CPU \u4e0d\u5207\u8d70)<\/span><br \/>\n<span class=\"token comment\">\/\/ \u4e34\u754c\u533a(\u4e0d\u80fd\u7761!)<\/span><br \/>\n<span class=\"token function\">preempt_enable<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>       <span class=\"token comment\">\/\/ \u5f00\u62a2\u5360(\u68c0\u67e5 need_resched)<\/span><\/p>\n<p><span class=\"token function\">local_irq_save<\/span><span class=\"token punctuation\">(<\/span>flags<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u5173\u4e2d\u65ad(\u672c CPU \u4e2d\u65ad\u4e0d\u6765)<\/span><br \/>\n<span class=\"token comment\">\/\/ \u4e34\u754c\u533a<\/span><br \/>\n<span class=\"token function\">local_irq_restore<\/span><span class=\"token punctuation\">(<\/span>flags<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token class-name\">spinlock_t<\/span> lock<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">spin_lock<\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">&amp;<\/span>lock<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>       <span class=\"token comment\">\/\/ \u81ea\u65cb\u9501\u9690\u542b\u5173\u62a2\u5360(SMP)&#043; \u53ef\u80fd\u5173\u4e2d\u65ad<\/span><br \/>\n<span class=\"token function\">spin_unlock<\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">&amp;<\/span>lock<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<ul>\n<li>\u5173\u62a2\u5360:\u672c\u6838\u4e0d\u5207\u8d70,\u4f46\u4e2d\u65ad\u8fd8\u6765(\u4e2d\u65ad\u91cc\u53ef\u80fd schedule)<\/li>\n<li>\u5173\u4e2d\u65ad:\u4e2d\u65ad\u4e0d\u6765,\u7edd\u5bf9\u5b89\u9759<\/li>\n<li>\u81ea\u65cb\u9501:\u9690\u542b\u5173\u62a2\u5360(07 \u7bc7\u8be6\u8bb2)<\/li>\n<\/ul>\n<p>\u5173\u62a2\u5360\/\u6301\u9501\u65f6\u4e0d\u80fd\u7761\u7720 FreeRTOS \u4e34\u754c\u533a\u91cc\u80fd\u8c03\u963b\u585e API(\u4f1a\u5207\u8d70)\u3002Linux \u5173\u62a2\u5360\/\u6301\u81ea\u65cb\u9501\u65f6\u7edd\u5bf9\u4e0d\u80fd\u7761\u7720\u2014\u2014\u7761\u7720\u4f1a schedule(),\u4f46\u4f60\u5173\u4e86\u62a2\u5360,schedule \u5207\u4e0d\u51fa\u53bb,\u6b7b\u9501\/panic\u3002\u8fd9\u662f Linux \u6bd4 FreeRTOS \u4e25\u683c\u7684\u70b9\u3002\u80fd\u7761\u7684\u4e34\u754c\u533a\u7528 mutex(07 \u7bc7\u8be6\u8bb2)\u3002<\/p>\n<hr \/>\n<h2>\u4e5d\u3001fork \/ exec \/ wait(\u8fdb\u7a0b\u751f\u547d\u5468\u671f)<\/h2>\n<h3>9.1 fork()<\/h3>\n<p><span class=\"token class-name\">pid_t<\/span> pid <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ \u5b50\u8fdb\u7a0b<\/span><br \/>\n<span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ \u7236\u8fdb\u7a0b<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<ul>\n<li>fork() \u521b\u5efa\u5b50\u8fdb\u7a0b,\u590d\u5236\u7236\u7684 task_struct<\/li>\n<li>\u7528 COW(Copy-On-Write):\u9875\u8868\u590d\u5236,\u7269\u7406\u9875\u5171\u4eab,\u5199\u65f6\u624d\u590d\u5236(\u60f0\u6027,01 \u7bc7\u54f2\u5b66)<\/li>\n<li>\u5b50\u7ee7\u627f\u7236\u7684 mm\/files\/signals \u526f\u672c<\/li>\n<\/ul>\n<h3>9.2 exec()<\/h3>\n<p><span class=\"token function\">execl<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/bin\/ls&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;ls&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token string\">&#034;-l&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<ul>\n<li>\u66ff\u6362\u5f53\u524d\u8fdb\u7a0b\u7684\u4ee3\u7801\/\u6570\u636e\/\u5806\/\u6808(\u4e22\u5f03\u65e7 mm,\u5efa\u65b0 mm)<\/li>\n<li>PID \u4e0d\u53d8,\u4f46\u53d8\u6210\u65b0\u7a0b\u5e8f<\/li>\n<li>file_operations \u4fdd\u6301(\u6253\u5f00\u7684 fd \u9ed8\u8ba4\u4fdd\u7559,\u9664 FD_CLOEXEC \u6807\u8bb0\u7684)<\/li>\n<\/ul>\n<h3>9.3 wait()<\/h3>\n<p><span class=\"token class-name\">pid_t<\/span> pid <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">wait<\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">&amp;<\/span>status<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u7b49\u4efb\u4e00\u5b50\u8fdb\u7a0b<\/span><\/p>\n<ul>\n<li>\u7236 wait \u6536\u5c38\u5b50\u8fdb\u7a0b<\/li>\n<li>\u5b50 exit \u540e\u53d8 ZOMBIE,\u7236 wait \u624d\u5f7b\u5e95\u91ca\u653e<\/li>\n<li>\u7236\u4e0d wait \u2192 \u5b50\u53d8\u50f5\u5c38,\u5360 PID;\u7236\u6b7b\u4e86 \u2192 init \u6536\u517b\u6536\u5c38<\/li>\n<\/ul>\n<h3>9.4 \u5b64\u513f\u8fdb\u7a0b\u4e0e\u50f5\u5c38<\/h3>\n<ul>\n<li>\u5b64\u513f:\u7236\u6b7b\u4e86,\u5b50\u88ab init(PID1)\u6536\u517b,init wait \u6536\u5c38<\/li>\n<li>\u50f5\u5c38:\u5b50\u6b7b\u4e86\u7236\u6ca1 wait,\u5360 PID \u548c\u9000\u51fa\u7801,\u7236 wait \u6216\u7236\u6b7b\u540e init \u6536\u5c38<\/li>\n<\/ul>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2:fork \u6bd4 FreeRTOS \u521b\u5efa\u4efb\u52a1\u91cd FreeRTOS xTaskCreate \u7acb\u5373\u5206\u914d\u6808\u548c TCB\u3002Linux fork \u7528 COW,\u770b\u4f3c\u590d\u5236 mm,\u5b9e\u9645\u53ea\u590d\u5236\u9875\u8868(\u5feb),\u7269\u7406\u9875\u5199\u65f6\u624d\u590d\u5236\u3002\u4f46 fork \u4ecd\u6bd4 xTaskCreate \u91cd\u2014\u2014\u8981\u590d\u5236 files\/signals\/\u9875\u8868\u3002\u6240\u4ee5 Linux \u670d\u52a1\u5668\u7528\u8fdb\u7a0b\u6c60\/\u7ebf\u7a0b,\u4e0d\u9891\u7e41 fork\u3002\u4f60\u5199\u670d\u52a1\u522b\u65e0\u8111 fork\u3002<\/p>\n<hr \/>\n<h2>\u5341\u3001\u8fdb\u7a0b\u5173\u7cfb\u4e0e\u4f1a\u8bdd<\/h2>\n<h3>10.1 \u8fdb\u7a0b\u7ec4 \/ \u4f1a\u8bdd<\/h3>\n<ul>\n<li>\u8fdb\u7a0b\u7ec4:\u76f8\u5173\u8fdb\u7a0b\u96c6\u5408(\u5982 pipeline),\u7ec4 ID &#061; PGID<\/li>\n<li>\u4f1a\u8bdd:\u8fdb\u7a0b\u7ec4\u96c6\u5408,\u4f1a\u8bdd\u9996\u63a7\u5236\u7ec8\u7aef,\u4f1a\u8bdd ID &#061; SID<\/li>\n<li>\u7528\u9014:\u4fe1\u53f7\u5e7f\u64ad(kill -PGID)\u3001\u4f5c\u4e1a\u63a7\u5236<\/li>\n<\/ul>\n<h3>10.2 \u5b88\u62a4\u8fdb\u7a0b(daemon)<\/h3>\n<p><span class=\"token comment\">\/\/ daemon \u5316\u5178\u578b\u6b65\u9aa4<\/span><br \/>\npid <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>          <span class=\"token comment\">\/\/ \u7236\u9000\u51fa<\/span><br \/>\n<span class=\"token function\">setsid<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>                      <span class=\"token comment\">\/\/ \u5b50\u5efa\u65b0\u4f1a\u8bdd,\u8131\u79bb\u63a7\u5236\u7ec8\u7aef<\/span><br \/>\n<span class=\"token function\">fork<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>                        <span class=\"token comment\">\/\/ \u518d fork,\u9632\u518d\u83b7\u63a7\u5236\u7ec8\u7aef<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pid <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token function\">exit<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">chdir<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\/&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>                    <span class=\"token comment\">\/\/ \u6539\u6839<\/span><br \/>\n<span class=\"token function\">umask<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token comment\">\/\/ \u5173\u6807\u51c6 fd,\u91cd\u5b9a\u5411\u5230 \/dev\/null<\/span><\/p>\n<ul>\n<li>\u5b88\u62a4\u8fdb\u7a0b:\u540e\u53f0\u8fd0\u884c,\u65e0\u63a7\u5236\u7ec8\u7aef<\/li>\n<li>BSP \u542f\u52a8\u540e\u53f0\u670d\u52a1\u5e38 daemon \u5316<\/li>\n<\/ul>\n<hr \/>\n<h2>\u5341\u4e00\u3001\u5e38\u7528\u8fdb\u7a0b\u8c03\u8bd5<\/h2>\n<h3>11.1 \u5de5\u5177<\/h3>\n<table>\n<tr>\u5de5\u5177\u770b\u4ec0\u4e48<\/tr>\n<tbody>\n<tr>\n<td>ps aux \/ ps -ef<\/td>\n<td>\u8fdb\u7a0b\u5217\u8868<\/td>\n<\/tr>\n<tr>\n<td>top \/ htop<\/td>\n<td>\u5b9e\u65f6\u8fdb\u7a0b\u72b6\u6001\/CPU<\/td>\n<\/tr>\n<tr>\n<td>pstree<\/td>\n<td>\u8fdb\u7a0b\u6811<\/td>\n<\/tr>\n<tr>\n<td>cat \/proc\/&lt;pid&gt;\/status<\/td>\n<td>\u8fdb\u7a0b\u8be6\u60c5(\u72b6\u6001\/\u5185\u5b58\/\u4fe1\u53f7)<\/td>\n<\/tr>\n<tr>\n<td>cat \/proc\/&lt;pid&gt;\/sched<\/td>\n<td>\u8c03\u5ea6\u4fe1\u606f(vruntime\/policy)<\/td>\n<\/tr>\n<tr>\n<td>cat \/proc\/&lt;pid&gt;\/maps<\/td>\n<td>\u5730\u5740\u7a7a\u95f4\u5e03\u5c40<\/td>\n<\/tr>\n<tr>\n<td>cat \/proc\/&lt;pid&gt;\/stack<\/td>\n<td>\u5185\u6838\u6808(WARNING)<\/td>\n<\/tr>\n<tr>\n<td>strace -p &lt;pid&gt;<\/td>\n<td>\u8ddf\u8e2a\u7cfb\u7edf\u8c03\u7528<\/td>\n<\/tr>\n<tr>\n<td>perf top<\/td>\n<td>\u70ed\u70b9\u51fd\u6570<\/td>\n<\/tr>\n<tr>\n<td>chrt \/ nice \/ renice<\/td>\n<td>\u6539\u8c03\u5ea6\u7b56\u7565\/\u4f18\u5148\u7ea7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>11.2 \u5173\u952e \/proc \u5b57\u6bb5<\/h3>\n<p># \/proc\/&lt;pid&gt;\/status<br \/>\nState:  R (running)<br \/>\nPid:    1234<br \/>\nPPid:   1<br \/>\nUid:    0<br \/>\nvoluntary_ctxt_switches:    1500   # \u4e3b\u52a8\u7761\u7720\u5207\u6362<br \/>\nnonvoluntary_ctxt_switches: 30     # \u88ab\u62a2\u5360\u5207\u6362<\/p>\n<ul>\n<li>voluntary \u591a &#061; \u9891\u7e41\u7b49 IO\/\u7761\u7720(\u6b63\u5e38)<\/li>\n<li>nonvoluntary \u591a &#061; \u9891\u7e41\u88ab\u62a2\u5360(\u53ef\u80fd CPU \u7d27\u5f20)<\/li>\n<\/ul>\n<p>\u5d4c\u5165\u5f0f\u89c6\u89d2: Linux \u7684 perf \u7edf\u8ba1\u4efb\u610f\u51fd\u6570\/CPU \u5468\u671f\u3002\/proc\/&lt;pid&gt;\/sched \u770b vruntime \u5224\u65ad\u8fdb\u7a0b\u662f\u5426\u88ab\u516c\u5e73\u8c03\u5ea6\u300216 \u7bc7\u8be6\u8bb2 perf\/ftrace\u3002<\/p>\n<hr \/>\n<h2>\u5341\u4e8c\u3001\u672c\u7bc7\u5c0f\u7ed3<\/h2>\n<ul>\n<li>task_struct \u662f\u5b87\u5b99\u4e2d\u5fc3,\u6bd4 FreeRTOS TCB \u80d6\u5341\u500d(mm\/files\/signals\/namespace)<\/li>\n<li>\u8fdb\u7a0b\u72b6\u6001:RUNNING\/INTERRUPTIBLE\/UNINTERRUPTIBLE(D,\u6740\u4e0d\u6389)\/ZOMBIE \u7b49<\/li>\n<li>Linux \u4e0d\u533a\u5206\u8fdb\u7a0b\u7ebf\u7a0b(\u90fd task_struct,clone flag \u63a7\u5236\u5171\u4eab);\u5185\u6838\u7ebf\u7a0b\u65e0 mm<\/li>\n<li>\u4e0a\u4e0b\u6587\u5207\u6362 context_switch:\u5207\u9875\u8868(switch_mm)&#043; \u5207\u5bc4\u5b58\u5668(switch_to,\u53ea\u5b58 callee-saved),\u5bf9\u7167\u4f60 mscratch \u5207\u6808\u662f\u653e\u5927\u7248<\/li>\n<li>CFS:vruntime \u6700\u5c0f\u4f18\u5148\u8dd1,\u7ea2\u9ed1\u6811,\u6743\u91cd\u7531 nice \u51b3\u5b9a;\u4e0d\u4f1a\u997f\u6b7b\u8fdb\u7a0b\u4f46\u5b9e\u65f6\u6027\u5f31<\/li>\n<li>EEVDF(6.6&#043;):CFS \u6f14\u8fdb,\u52a0 lag\/vdeadline,\u66f4\u516c\u5e73<\/li>\n<li>\u8c03\u5ea6\u7b56\u7565:SCHED_NORMAL(CFS)\/SCHED_FIFO\/RR(RT)\/SCHED_DEADLINE(\u786c\u5b9e\u65f6)<\/li>\n<li>\u62a2\u5360:\u5173\u62a2\u5360\/\u6301\u81ea\u65cb\u9501\u65f6\u4e0d\u80fd\u7761\u7720(FreeRTOS \u4e34\u754c\u533a\u80fd\u7761,Linux \u4e0d\u80fd,\u4e25\u683c)<\/li>\n<li>fork \u7528 COW(\u60f0\u6027),exec \u6362\u7a0b\u5e8f,wait \u6536\u5c38;\u5b64\u513f\u5f52 init,\u50f5\u5c38\u7b49\u6536\u5c38<\/li>\n<li>PREEMPT_RT \u8865\u4e01\u8ba9 Linux \u63a5\u8fd1\u786c\u5b9e\u65f6<\/li>\n<\/ul>\n<hr \/>\n<h2>\u901f\u67e5\u8868<\/h2>\n<table>\n<tr>\u60f3\u5e72\u5565\u600e\u4e48\u505a<\/tr>\n<tbody>\n<tr>\n<td>\u770b\u8fdb\u7a0b\u5217\u8868<\/td>\n<td>ps aux \/ top \/ htop<\/td>\n<\/tr>\n<tr>\n<td>\u770b\u8fdb\u7a0b\u8be6\u60c5<\/td>\n<td>cat \/proc\/\/status<\/td>\n<\/tr>\n<tr>\n<td>\u770b\u5730\u5740\u7a7a\u95f4<\/td>\n<td>cat \/proc\/\/maps<\/td>\n<\/tr>\n<tr>\n<td>\u770b\u8c03\u5ea6\u4fe1\u606f<\/td>\n<td>cat \/proc\/\/sched<\/td>\n<\/tr>\n<tr>\n<td>\u6539\u4f18\u5148\u7ea7<\/td>\n<td>nice -n 10 .\/app \/ renice -n -5 -p PID<\/td>\n<\/tr>\n<tr>\n<td>\u6539\u8c03\u5ea6\u7b56\u7565<\/td>\n<td>chrt -f 80 .\/app<\/td>\n<\/tr>\n<tr>\n<td>\u521b\u5efa\u5185\u6838\u7ebf\u7a0b<\/td>\n<td>kthread_run(fn, arg, \u201cname\u201d)<\/td>\n<\/tr>\n<tr>\n<td>\u8ddf\u8e2a syscall<\/td>\n<td>strace -p PID<\/td>\n<\/tr>\n<tr>\n<td>\u770b\u8fdb\u7a0b\u6811<\/td>\n<td>pstree -p<\/td>\n<\/tr>\n<tr>\n<td>\u6740\u8fdb\u7a0b<\/td>\n<td>kill -9 PID(D \u72b6\u6001\u6740\u4e0d\u6389)<\/td>\n<\/tr>\n<tr>\n<td>\u770b\u50f5\u5c38<\/td>\n<td>ps aux | grep Z<\/td>\n<\/tr>\n<tr>\n<td>\u5b9e\u65f6\u6027<\/td>\n<td>SCHED_FIFO\/RR\/DEADLINE \u6216 PREEMPT_RT<\/td>\n<\/tr>\n<tr>\n<td>\u5173\u62a2\u5360<\/td>\n<td>preempt_disable(\u4e0d\u80fd\u7761)<\/td>\n<\/tr>\n<tr>\n<td>\u7761\u7720\u7b49\u5f85<\/td>\n<td>TASK_INTERRUPTIBLE(\u53ef\u88ab\u4fe1\u53f7\u5524\u9192)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr \/>\n<p>&#x1f4a1;\u6280\u672f\u4e4b\u8def\u6f2b\u6f2b&#xff0c;\u5206\u4eab\u662f\u4e3a\u4e86\u66f4\u597d\u5730\u4ea4\u6d41\u3002\u5982\u679c\u672c\u6587\u7684\u5185\u5bb9\u5bf9\u4f60\u6709\u542f\u53d1&#xff0c;\u5e0c\u671b\u80fd\u5f97\u5230\u4f60\u7684 \u70b9\u8d5e &#x1f44d; \u548c \u6536\u85cf \u2b50\u3002<\/p>\n<p>\u5982\u679c\u4f60\u5728\u8c03\u8bd5\u8fc7\u7a0b\u4e2d\u9047\u5230\u4e86\u5176\u4ed6\u95ee\u9898&#xff0c;\u6b22\u8fce\u5728 \u8bc4\u8bba\u533a &#x1f4ac; \u7559\u8a00&#xff0c;\u6211\u4eec\u4e00\u8d77\u63a2\u8ba8\u3002\u4e5f\u6b22\u8fce \u5173\u6ce8 &#x1f440; \u6211&#xff0c;\u4e00\u8d77\u4ea4\u6d41\u5e95\u5c42\u5f00\u53d1\u7684\u90a3\u4e9b\u4e8b\u513f\u3002<\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u7bc7\u5b9a\u4f4d:Linux \u5185\u6838\u7684\\&#8221;\u5b87\u5b99\u4e2d\u5fc3\\&#8221;\u662f 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