gprof

I used to do all my Linux profiling with gprof . However, with my multi-threaded application, it's output appears to be inconsistent. Now, I dug this up: http://sam.zoy.org/writings/programming/gprof.html However, it's from a long time ago and in my gprof output, it appears my gprof is listing functions used by non-main threads. So, my questions are: 1) In 2010, can I easily use gprof to profile multi-threaded Linux C++ applications? ( Ubuntu 9.10 ) 2) What other tools should I look into for profiling? Laurynas Biveinis Edit: added another answer on poor man's profiler, which IMHO is better

I'm trying to profile a C++ application with gprof on a machine running OSX 10.5.7. I compile with g++ in the usual way, but using -pg flags, run the application and try to view the call graph with gprof. Unfortunately my call graph contains all zeroes for all time columns. The values in the "called" columns have reasonable values so it looks like something was profiled but I'm mystified about the lack of other data. All my source files are compiled in a similar way: g++ -pg -O2 -DNDEBUG -I./ -ansi -c -o ScenarioLoader.o ScenarioLoader.cpp I then run 'ar' to bundle all the object files into a

原文： http://www.cnblogs.com/me115/archive/2013/06/05/3117967.html 1. 二八法则：在任何一组东西中，最重要的只占其中一小部分，约20%，其余80%的尽管是多数，却是次要的；在优化实践中，我们将精力集中在优化那20%最耗时的代码上，整体性能将有显著的提升；这个很好理解。函数A虽然代码量大，但在一次正常执行流程中，只调用了一次。而另一个函数B代码量比A小很多，但被调用了1000次。显然，我们更应关注B的优化。 2. 编完代码，再优化；编码的时候总是考虑最佳性能未必总是好的；在强调最佳性能的编码方式的同时，可能就损失了代码的可读性和开发效率； 工具： 1 Gprof 工欲善其事，必先利其器。对于Linux平台下C++的优化，我们使用gprof工具。gprof是GNU profile工具，可以运行于linux、AIX、Sun等操作系统进行C、C++、Pascal、Fortran程序的性能分析，用于程序的性能优化以及程序瓶颈问题的查找和解决。通过分析应用程序运行时产生的“flat profile”，可以得到每个函数的调用次数，消耗的CPU时间（只统计CPU时间，对IO瓶颈无能为力），也可以得到函数的“调用关系图”，包括函数调用的层次关系，每个函数调用花费了多少时间。 2. gprof使用步骤 1) 用gcc、g++