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c++linuxredhatdynamic-linking

Timing shared library load times on linux

I'm trying to figure out how much time I'm taking in loading shared libraries on a linux system (RHEL 6 to be specific) and I'm wondering what sort of tools are out there to time how long shared library loading takes. I haven't really found any good information out there as to how to do this and I'm hoping some sort of tool exists.

Solution

  • You should run under LD_DEBUG=statistics:

    $ LD_DEBUG=statistics ls > /dev/null
      9897:
      9897:     runtime linker statistics:
      9897:       total startup time in dynamic loader: 1557664 clock cycles
      9897:                 time needed for relocation: 322049 clock cycles (20.6%)
      9897:                      number of relocations: 156
      9897:           number of relocations from cache: 8
      9897:             number of relative relocations: 1257
      9897:                time needed to load objects: 1037549 clock cycles (66.6%)