来自： http://blog.csdn.net//clh604/article/details/21934453
当php程序逻辑执行很复杂的时候，可能会带来性能上的问题，为了有效的找到影响性能的代码，推荐大家使用PHP新能分析工具XHProf，该工具能有效的分析每段代码的执行情况，非常好用
$ wget https://github.com/facebook/xhprof/tarball/master -O xhprof.tar.gz$ tar zxf xhprof.tar.gz$ cd facebook-xhprof-b8c76ac/extension/# phpize# ./configure --with-php-config=`/path/to/php-config`# make && make install# make test# vi /etc/php.d/xhprof.ini; 内容为：extension = xhprof.so; 注意：output_dir 必须存在且可写xhprof.output_dir = /tmp/xhpro然后重启apache服务# service php-fpm restart 或 service httpd restart
// start profilingxhprof_enable();// run program....// stop profiler$xhprof_data = xhprof_disable();//// Saving the XHProf run// using the default implementation of iXHProfRuns.//include_once $XHPROF_ROOT . "/xhprof_lib/utils/xhprof_lib.php";include_once $XHPROF_ROOT . "/xhprof_lib/utils/xhprof_runs.php";$xhprof_runs = new XHProfRuns_Default();// Save the run under a namespace "xhprof_foo".//// **NOTE**:// By default save_run() will automatically generate a unique// run id for you. [You can override that behavior by passing// a run id (optional arg) to the save_run() method instead.]//$run_id = $xhprof_runs->save_run($xhprof_data, "xhprof_foo");echo "---------------\n"."Assuming you have set up the http based UI for \n"."XHProf at some address, you can view run at \n"."http://<xhprof-ui-address>/index.php?run=$run_id&source=xhprof_foo\n"."---------------\n";如此一来，会在上面设定的xhprof.output_dir目录里生成名字类似49bafaa3a3f66.xhprof_foo的数据文件，可以很方便的通过Web方式浏览效果：
在 xhprof 源码包中提供了xhprof_html 和 xhprof_lib 两个文件夹，xhprof_lib是用于 PHP 开发，而xhprof_html用于显示 xhprof 分析结果的 web 界面,访问形式如下
