#13164: idle time full GCs (idle cpu usage) -------------------------------------+------------------------------------- Reporter: lspitzner | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 8.0.1 Resolution: | Keywords: idle GC Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonmar):
I just noticed that this means that you do not get deadlock detection if you forkIO (forever (threadDelay 100000)). That's interesting.
Probably because it never runs a major GC, only minor GCs. Admittedly that's surprising and counter-intuitive.
I do care that interactive programs I'm not actively using don't consume 12% of my CPU.
I'm sympathetic to that. Like I said, I'm open to suggestions here. I do worry that not having deadlock detection by default will be surprising - it's quite useful when developing/debugging, for instance. We have lots of tests in `testsuite/tests/concurrent` that rely on it. How about we give the idle GC a time budget expressed as a % of wall clock time? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13164#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler