diff options
| -rw-r--r-- | configure.ac | 14 | ||||
| -rw-r--r-- | docs/users_guide/8.12.1-notes.rst | 11 | ||||
| -rw-r--r-- | rts/win32/OSMem.c | 2 |
3 files changed, 21 insertions, 6 deletions
diff --git a/configure.ac b/configure.ac index 84880d8cb4..070f7ce56c 100644 --- a/configure.ac +++ b/configure.ac @@ -1219,11 +1219,15 @@ if test "$ac_cv_sizeof_void_p" -eq 8 ; then if test "x$EnableLargeAddressSpace" = "xyes" ; then if test "$ghc_host_os" = "darwin" ; then use_large_address_space=yes - elif test "$ghc_host_os" = "openbsd" ; then - # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE. - # The flag MAP_NORESERVE is supported for source compatibility reasons, - # but is completely ignored by OS mmap - use_large_address_space=no + elif test "$ghc_host_os" = "openbsd" ; then + # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE. + # The flag MAP_NORESERVE is supported for source compatibility reasons, + # but is completely ignored by OS mmap + use_large_address_space=no + elif test "$ghc_host_os" = "mingw32" ; then + # as of Windows 8.1/Server 2012 windows does no longer allocate the page + # tabe for reserved memory eagerly. So we are now free to use LAS there too. + use_large_address_space=yes else AC_CHECK_DECLS([MAP_NORESERVE, MADV_FREE, MADV_DONTNEED],[],[], [ diff --git a/docs/users_guide/8.12.1-notes.rst b/docs/users_guide/8.12.1-notes.rst index c729a8ec6c..bc2414489f 100644 --- a/docs/users_guide/8.12.1-notes.rst +++ b/docs/users_guide/8.12.1-notes.rst @@ -40,6 +40,11 @@ Highlights GHC is now able to detect the case alt returning 3 as redundant. - Some more performance improvements in edge cases. +* Windows: Use the larg address space allocator. + + This improves runtime but causes increased memory usage on Windows versions + older than Win 8.1/Server 2012. + Full details ------------ @@ -166,6 +171,12 @@ Runtime system - Support for Windows Vista has been dropped. GHC-compiled programs now require Windows 7 or later. +- Windows now uses the large address space allocator by default. + In extreme cases we saw improvements by up to 3% decreased runtime. + + The downside is that haskell apps run on older (Pre Win-8.1/Server 2012) + systems will have higher memory footprints. + Template Haskell ~~~~~~~~~~~~~~~~ diff --git a/rts/win32/OSMem.c b/rts/win32/OSMem.c index 35fe72fd58..dd0f60ff0a 100644 --- a/rts/win32/OSMem.c +++ b/rts/win32/OSMem.c @@ -459,7 +459,7 @@ void *osReserveHeapMemory (void *startAddress, W_ *len) void *start; heap_base = VirtualAlloc(startAddress, *len + MBLOCK_SIZE, - MEM_RESERVE, PAGE_READWRITE); + MEM_RESERVE | MEM_TOP_DOWN, PAGE_READWRITE); if (heap_base == NULL) { if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY) { errorBelch("out of memory"); |