C gperftools - 分析 C 代码

Question

我正在尝试为我使用 gperftools 的代码生成分析(逐行源代码)。

gcc a.c -lprofiler -Wl,--no-as-needed -lprofiler -Wl,--as-needed

CPUPROFILE=out.ptof ./a.out 

但是

pprof  ./a.out out.ptof --inuse_objects --lines --heapcheck  --edgefraction=1e-10 --nodefraction=1e-10 --gv
Using local file ./a.out.
Using local file out.ptof.
No nodes to print

为什么 pprof 声明“没有要打印的节点”？

Answer 1

看来there might be several reasons 。

引用最有可能的(假设您的代码很简单):

If you see a message like "No nodes to print" [...] it simply means that the code was so fast that it couldn't be profiled - basically, the profiler never even had a chance to take a sample.

还有:

In the default mode, there will be no profiling data for the 'slow' route, because it uses few CPU cycles (You'll see the message 'No nodes to print').

所以你可能需要人为地减慢你的程序......