[CentOS] firefox and D state

Previously when firefox went catatonic
to the point that I could not even scroll,
its CPU usage had gone to 100%+.
Now top tells me that firefox, Web Content (with a space)
or sometimes kswap... has process state D,
uninterruptable sleep.

Any suggestions on how to deal?

I often have a lot of tabs open,
so discovering the right one was hard enough before.
Usually, it was something relatively new, so that helped.
Not so much anymore.
I think a lot of it is just waiting (D) for ads or running them.

Closing and reopening sometimes works,
but then I have to go find all the video ads and stop
them one at a time.

-- 
Michael   hennebry at web.cs.ndsu.NoDak.edu
"Sorry but your password must contain an uppercase letter, a number,
a haiku, a gang sign, a heiroglyph, and the blood of a virgin."
                                                              --  someeecards