#7500: GHC: internal error: getMBlock: mmap: Operation not permitted ----------------------------------+------------------------------------ Reporter: guest | Owner: Type: bug | Status: patch Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.4.1 Resolution: | Keywords: Operating System: Linux | Architecture: Unknown/Multiple Type of failure: Runtime crash | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: ----------------------------------+------------------------------------ Comment (by Austin Seipp ): In [changeset:acb91b920ebac992c52594adf605b2caf98ab4c0/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="acb91b920ebac992c52594adf605b2caf98ab4c0" Treat EPERM error from mmap as an OOM (#7500) Linux can give back EPERM from an mmap call when a user program attempts to map pages near `mmap_min_addr`, which is a kernel security measure to prevent people from mapping pages at address 0. We may do this when we hint to mmap what address to map the pages to. However, it's theoretically possible we're not actually out of memory - we could have continuously mapped pages at some other place far away from `mmap_min_addr` and succeeded instead. So as an added precaution, if mmap for a given addr gives us EPERM, we'll also attempt to map *again*, but without the address hint. Maybe the kernel can do the right thing. However, while testing #7500, the amount of free address space we could have otherwise used only turns out to be about 139MB. Which isn't really a lot. So, given that, we *also* otherwise treat EPERM as an out of memory error. This fixes #7500. Signed-off-by: Austin Seipp }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7500#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler