#14193: Add RTS flag to disable 1TB address space allocaiton -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #9706, #14192 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- GHC 8.0 changed the default behaviour on Linux to allocate 1 TB virtual memory for Haskell programs (#9706). While shown to be good for performance (a small percentage gain), it has created me a couple problems, especially when: * trying to disable overcommit in Linux to get more reliable memory behaviour and avoid swapping / the OOM-killer (all Haskell programs crash at startup) * and in debugging (e.g. #14192) Currently you can turn that feature off only via a compile-time switch, e.g. `./configure --disable-large-address-space`. I'd like to request to make it possible to turn this behaviour off at run- time with an RTS flag, so that when the flag is given, it uses the old block-allocator. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14193 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler