Matt Dillon is bringing in resident executable support. This speeds loading of dynamically linked programs by saving a copy of their vmspace with vmspace_fork() in the kernel, and using that when executed instead of going through the regular, slower startup. This will replace prebinding.
Matt Dillon posted these preliminary numbers running a test program with Perl:
|dynamic:||2.860u 2.668s 0:05.61 98.3%||87+231k 0+0io 0pf+0w|
|prebinding:||1.821u 2.095s 0:03.90 100.2%||34+202k 0+0io 1pf+0w|
|resident:||1.239u 1.846s 0:03.08 99.6%||137+280k 0+0io 0pf+0w|
|statically linked:||0.418u 0.867s 0:01.28 99.2%||808+616k 0+0io 0pf+0w|
It is planned to make dynamic loading as fast as static. For those of you not familiar with the output of
time, the first column is total time taken, the second is time taken to run the tested program, and the third is time consumed by system overhead. Yes, there are more columns than that. No, I don’t know what they mean.