This was introduced here: https://ghc.haskell.org/trac/ghc/ticket/9706 Basically, if you can have a huge virtual address space (which you can on a 64bit architecture) then you can simplify the memory management logic. On 17 October 2016 at 14:23, Michael Alan Dorman wrote:

Hey, haskell-cafe,

I realize that this should not be a problem, but it is very strange to me that *every* haskell process on my system has a 1TB VSIZE. If I sort my `ps auwx` output on vsize, the top of the list looks like:

mdorman 1208 0.0 0.1 1074011536 12500 ? S Oct14 0:04 /home/mdorman/.xmonad/xmonad-x86_64-linux mdorman 21900 0.0 0.2 1074111408 19712 pts/1 Sl+ 09:06 0:00 cabal run melpa2nix -- --output melpa-generated.nix --melpa /home/mdorman/src/melpa --work /home/mdorman/src/emacs2nix/.workdir mdorman 1363 0.0 0.1 1074383784 13052 ? Sl Oct14 1:14 /home/mdorman/.cache/taffybar/taffybar-linux-x86_64 +RTS -I0 -V0 --RTS --dyre-master-binary=/nix/store/6skvglp84w5xzqx8dxxydazk1zj8h2ih-taffybar-0.4.6/bin/taffybar mdorman 21981 8.6 0.5 1076223012 42308 pts/1 Sl+ 09:06 0:19 /home/mdorman/src/emacs2nix/dist/build/melpa2nix/melpa2nix --output melpa-generated.nix --melpa /home/mdorman/src/melpa --work /home/mdorman/src/emacs2nix/.workdir

Each of those haskell processes has a vsize 5 orders of magnitude more than their resident set size, whether it's the two I always have running (xmonad and taffybar), or in this case, cabal itself, as well as the compiled executable it's running.

I've spent a reasonable amount of time attempting to google this, to no avail. Is this perhaps a peculiarity of how GHC was built? I'm running on nixos-unstable, using ghc-8.0.1---is there some compilation that we should or shouldn't be setting?

Thanks for any guidance,

Mike. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

-- Michael Walker (http://www.barrucadu.co.uk)