1# bytrace使用指导<a name="ZH-CN_TOPIC_0000001083359811"></a> 2 3- [简介](#section11388623181619) 4- [开发指导](#section1595564317164) 5- [使用实例](#section667273201818) 6 7## 简介<a name="section11388623181619"></a> 8 9bytrace是开发人员用于追踪进程轨迹、分析性能的一种工具，主要对内核ftrace进行了封装和扩展，来支持用户态的打点。通过该工具可以打开想要查看的用户态和内核label（通过下面命令行bytrace -l，查看支持的所有label），然后通过命令行进行抓取trace信息到指定文件中。 10 11## 开发指导<a name="section1595564317164"></a> 12 13bytrace当前支持以下命令: 14 15**表 1** 命令行列表 16 17<a name="table16802195914247"></a> 18<table><thead align="left"><tr id="row14804759142412"><th class="cellrowborder" valign="top" width="50%" id="mcps1.2.3.1.1"><p id="p1280465972411"><a name="p1280465972411"></a><a name="p1280465972411"></a>Option</p> 19</th> 20<th class="cellrowborder" valign="top" width="50%" id="mcps1.2.3.1.2"><p id="p380414595249"><a name="p380414595249"></a><a name="p380414595249"></a>Description</p> 21</th> 22</tr> 23</thead> 24<tbody><tr id="row1714512123414"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p1915412133419"><a name="p1915412133419"></a><a name="p1915412133419"></a>-h，--help</p> 25</td> 26<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p6156126341"><a name="p6156126341"></a><a name="p6156126341"></a>查看option帮助</p> 27</td> 28</tr> 29<tr id="row13804135982416"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p18051959152410"><a name="p18051959152410"></a><a name="p18051959152410"></a>-b <em id="i35979186184"><a name="i35979186184"></a><a name="i35979186184"></a>n</em>，--buffer_size <em id="i144491624181811"><a name="i144491624181811"></a><a name="i144491624181811"></a>n</em></p> 30</td> 31<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p0805165932419"><a name="p0805165932419"></a><a name="p0805165932419"></a>指定<em id="i134241333181817"><a name="i134241333181817"></a><a name="i134241333181817"></a>n</em>(KB)内存大小用于存取trace日志，默认2048KB</p> 32</td> 33</tr> 34<tr id="row580519592245"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p880510591241"><a name="p880510591241"></a><a name="p880510591241"></a>-t <em id="i8668143912203"><a name="i8668143912203"></a><a name="i8668143912203"></a>n</em>，--time <em id="i841433614202"><a name="i841433614202"></a><a name="i841433614202"></a>n</em></p> 35</td> 36<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p1480517591245"><a name="p1480517591245"></a><a name="p1480517591245"></a>用来指定trace运行的时间（单位：s），取决于需要分析过程的时间</p> 37</td> 38</tr> 39<tr id="row4806175913247"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p980655912242"><a name="p980655912242"></a><a name="p980655912242"></a>--trace_clock <em id="i19464452217"><a name="i19464452217"></a><a name="i19464452217"></a>clock</em></p> 40</td> 41<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p11806959142416"><a name="p11806959142416"></a><a name="p11806959142416"></a>trace输出的时钟类型，一般设备支持boot、global、mono、uptime、perf等，默认为boot</p> 42</td> 43</tr> 44<tr id="row1280635917242"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p180715591244"><a name="p180715591244"></a><a name="p180715591244"></a>--trace_begin</p> 45</td> 46<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p480795916243"><a name="p480795916243"></a><a name="p480795916243"></a>启动抓trace</p> 47</td> 48</tr> 49<tr id="row1580717599245"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p38073598242"><a name="p38073598242"></a><a name="p38073598242"></a>--trace_dump</p> 50</td> 51<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p148077595245"><a name="p148077595245"></a><a name="p148077595245"></a>将数据输出到指定位置（默认控制台）</p> 52</td> 53</tr> 54<tr id="row180811592242"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p11808165922419"><a name="p11808165922419"></a><a name="p11808165922419"></a>--trace_finish</p> 55</td> 56<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p18809559182420"><a name="p18809559182420"></a><a name="p18809559182420"></a>停止抓trace，并将数据输出到指定位置（默认控制台）</p> 57</td> 58</tr> 59<tr id="row2809185972420"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p2080925922418"><a name="p2080925922418"></a><a name="p2080925922418"></a>-l，--list_categories</p> 60</td> 61<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p38091159142414"><a name="p38091159142414"></a><a name="p38091159142414"></a>输出手机能支持的trace模块</p> 62</td> 63</tr> 64<tr id="row1880912598248"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p1681014595244"><a name="p1681014595244"></a><a name="p1681014595244"></a>--overwrite</p> 65</td> 66<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p12810165914248"><a name="p12810165914248"></a><a name="p12810165914248"></a>当缓冲区满的时候，将丢弃最新的信息。（默认丢弃最老的日志）</p> 67</td> 68</tr> 69<tr id="row1181015992414"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p168101859152415"><a name="p168101859152415"></a><a name="p168101859152415"></a>-o <em id="i1367232742113"><a name="i1367232742113"></a><a name="i1367232742113"></a>filename</em>，--output <em id="i4305133012219"><a name="i4305133012219"></a><a name="i4305133012219"></a>filename</em></p> 70</td> 71<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p9810559132410"><a name="p9810559132410"></a><a name="p9810559132410"></a>指定输出的目标文件名称</p> 72</td> 73</tr> 74<tr id="row8810155982415"><td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.1 "><p id="p381145912410"><a name="p381145912410"></a><a name="p381145912410"></a>-z</p> 75</td> 76<td class="cellrowborder" valign="top" width="50%" headers="mcps1.2.3.1.2 "><p id="p1281117592249"><a name="p1281117592249"></a><a name="p1281117592249"></a>抓取trace后进行压缩</p> 77</td> 78</tr> 79</tbody> 80</table> 81 82## 使用实例<a name="section667273201818"></a> 83 84以下是常用bytrace命令示例，供开发者参考： 85 86- 查询支持的label。 87 88``` 89bytrace -l 90``` 91 92或者 93 94``` 95bytrace --list_categories 96``` 97 98- 设置4M缓存，抓取10秒，抓取label为ability的trace信息。 99 100``` 101bytrace -b 4096 -t 10 --overwrite ability > /data/mytrace.ftrace 102``` 103 104- 设置trace的输出时钟为mono。 105 106``` 107bytrace --trace_clock mono -b 4096 -t 10 --overwrite ability > /data/mytrace.ftrace 108``` 109 110- 抓取trace后进行压缩。 111 112``` 113bytrace -z -b 4096 -t 10 --overwrite ability > /data/mytrace.ftrace 114``` 115 116