#11587: Place shared objects in LIBDIR -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Package | Version: 7.10.3 system | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- If one compiles a program with `-dynamic`, the resulting executable includes in its `rpath` the library directory of every Haskell package that the program links against. This causes a significant number of excess system calls at program start-up. For instance, in the case of a dynamically linked `ghc` executable on Debian 8, compiling a trivial "hello world" application produces over 800 `open` calls, the majority of which originate from the dynamic linker. e.g., {{{ $ strace -f -e open ghc-7.10.3 -c -fforce-recomp Test.hs 2>&1 | grep open ... open("/usr/lib/ghc/bin/../haske_GGvi737nHHfG6zm2y7Rimi/tls/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../haske_GGvi737nHHfG6zm2y7Rimi/tls/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../haske_GGvi737nHHfG6zm2y7Rimi/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../haske_GGvi737nHHfG6zm2y7Rimi/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../termi_6iVf4EBnOgfIaaOCLRs8jl/tls/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../termi_6iVf4EBnOgfIaaOCLRs8jl/tls/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../termi_6iVf4EBnOgfIaaOCLRs8jl/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../termi_6iVf4EBnOgfIaaOCLRs8jl/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../ghc_0AG9TOjDEtx4Ji3wSwHOBe/tls/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../ghc_0AG9TOjDEtx4Ji3wSwHOBe/tls/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib/ghc/bin/../ghc_0AG9TOjDEtx4Ji3wSwHOBe/x86_64/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) ... }}} The dynamic linker must look in nearly 25 Haskell library directories to locate every system library! This is madness. Instead of placing each shared library in its own directory, `$LIBDIR/$PKG_KEY/lib$PKG_KEY.so` as we do currently, why not just place them in `$LIBDIR`, e.g. `$LIBDIR/libPKG_KEY.so`. This would mean that we need to include only one directory, `$LIBDIR`, in `rpath`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11587 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler