#10587: Suspending and unsuspending ghci kills and spawns threads ---------------------------------+----------------------------------------- Reporter: niteria | Owner: Type: bug | Status: new Priority: low | Milestone: Component: GHCi | Version: 7.10.1 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: ---------------------------------+----------------------------------------- Changes (by niteria): * owner: niteria => Comment: I've tried to change it, so that the number of IO manager threads gets decreased when number of capabilities decreases, but I couldn't come up with a solution that satisfied me. The main problem is that the thread is not the only resource associated with the IO manager, there are also callback that should be executed in the future. If we stopped the thread before its loop is empty, we would break the promise of executing that callback. This problem is also described here: https://phabricator.haskell.org/rGHC12f3fef5ec52c1ec0958b674adcd981f48048428 I've considered: * Checking if the loop is empty - I couldn't tell if all the implementations support that, so I abandoned that idea * Migrating the file descriptors and callbacks to another instance of IO manager - the problem is that it isn't obvious which one to migrate to and if we'd want to spread them across available ones. @simonmar suggested just being less aggressive about killing spare workers. I'm starting to like that idea. I'm out of ideas and it's not really that urgent for me, so I'll suspend working on this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10587#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler