Each column has a description of what it means if you set your mouse to hover over it in Firebug. I’ll assume you can read up on how each column works on your own then. However, you have definitely come across some odd behavior which needs to be explained. The own time is the amount … Read more
Use gprof. Just compile with -pg flag (I think (but am not sure) you have to turn of optimizations though.) and use gprof to analyze the gmon.out file that your executable will then produce. eg: gcc -pg -o whatever whatever.c ./whatever gprof whatever gmon.out Same thing with g++ and cpp.
Luaan posted the solution in the comments above, it’s the system wide timer resolution. Default resolution is 15.6 ms, the profiler sets the resolution to 1ms. I had the exact same problem, very slow execution that would speed up when the profiler was opened. The problem went away on my PC but popped back up … Read more
Having just read the paper (again), let me try to explain it. Suppose it takes samples at 100Hz, except not when the process is blocked for IO or some other reason. Each sample records the PC, which is in some function. The count of samples in that function is incremented. So, at the end of … Read more
Using gcc, I compile and link with -pg (as explained e.g. here), then continue by running the program (according to the principles also suggested at that URL) and using gprof. The tools will vary if you’re using different compilers &c, but the URL is still recommended, even then, for the parts that are about general … Read more
Sometimes just plain SQL logging (enabled via python’s logging module or via the echo=True argument on create_engine()) can give you an idea how long things are taking. For example if you log something right after a SQL operation, you’d see something like this in your log: 17:37:48,325 INFO [sqlalchemy.engine.base.Engine.0x…048c] SELECT … 17:37:48,326 INFO [sqlalchemy.engine.base.Engine.0x…048c] {<params>} … Read more
At my workplace we use AQTime. It’s not free ($600 or 30-day trial) but it really works wonders. I like it because it can handle both native (we do C++) and managed code. It works in stand-alone mode, integrates with Visual Studio, and also works with Borland’s IDE (for those C++ Builder and Delphi fans … Read more
First: Time sampling profilers are more robust than CPU sampling profilers. I’m not extremely familiar with Windows development tools so I can’t say which ones are which. Most profilers are CPU sampling. A CPU sampling profiler grabs a stack trace every N instructions. This technique will reveal portions of your code that are CPU bound. … Read more
There are a number of performance analysis tools specialized for Parallel/MPI Programs, such as: Score-P, which works with a number of different Analysis tools, e.g. Cube, Vampir HPCToolkit uses sampling only, so you do not have to recompile your application Tau At first they may not be as simple to use simple to use, but … Read more
Use massif, which is part of the Valgrind tools. massif-visualizer can help you graph the data or you can just use the ms_print command.