Coolio Arrested -- Locked Up at Same Jail as Son

Like father, like son ...

TMZ has learned rapper Coolio was arrested in Las Vegas today ... and is currently behind bars at the same jail as his kid.

Law enforcement tells TMZ ... Coolio was a passenger in a Nissan Versa which was pulled over for a routine traffic violation early Friday morning.

We're told the cops ran Coolio's name in the system and noticed he had 2 active bench warrants out for his arrest stemming from multiple traffic violations.

Coolio was arrested and hauled to Clark County Detention Center -- the same place where his son Grtis is rotting away for allegedly robbing some dude at gunpoint a few months ago.

Coolio's bail has been set at $5,850. A court date has not yet been set.

4:32 PM PT: Coolio has since posted bail and been released.