Performance issue when waiting for half sec for job to finish before continuing

[asrubylife]

This line was added to pause for a half a second to conserve system resources

php-resque/lib/Worker/ResqueWorker.php

Line 287 in 050a337

usleep(500000);

However that makes processing jobs very slow. Changing that to say 500 improves queue processing performance drastically.

Making this configurable would allow the user to change it.