Does yesod uses the processor when idle?

Question

I have created a very simple application using yesod. It's not very used, but when I check with htop, it has consumed more cpu time than all other processes in the server, including processes that are running for a much bigger time. Also, when I start the process I see that it's processor usage time keeps increasing even when no requests are made (most of the time no requests are made). Is this common or expected with yesod apps?

Answer 1

Try disable idle GC:

./app +RTS -I0 -RTS

Probably, yesod have a thread that updates IORef with current time which triggers idle GC, like in this ticket http://hackage.haskell.org/trac/ghc/ticket/4322