X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=rts%2Fposix%2FOSMem.c;h=0a372560227027f4b79c6e0d1c4dde71a97f789d;hp=6e8337bdc687e3d75176f1241efbabfa21a5d0e5;hb=a2a67cd520b9841114d69a87a423dabcb3b4368e;hpb=e3c55aebd4f9ce7a5b4390d4726612865fd207f2 diff --git a/rts/posix/OSMem.c b/rts/posix/OSMem.c index 6e8337b..0a37256 100644 --- a/rts/posix/OSMem.c +++ b/rts/posix/OSMem.c @@ -1,26 +1,216 @@ /* ----------------------------------------------------------------------------- * - * (c) The University of Glasgow 2006 + * (c) The University of Glasgow 2006-2007 * * OS-specific memory management * * ---------------------------------------------------------------------------*/ +// This is non-posix compliant. +// #include "PosixSource.h" + #include "Rts.h" -#include "OSMem.h" +#include "sm/OSMem.h" + +#ifdef HAVE_UNISTD_H #include +#endif +#ifdef HAVE_SYS_TYPES_H #include +#endif +#ifdef HAVE_SYS_MMAN_H #include +#endif +#ifdef HAVE_STRING_H +#include +#endif +#ifdef HAVE_FCNTL_H +#include +#endif + +#include + +#if darwin_HOST_OS +#include +#include +#endif + +static caddr_t next_request = 0; + +void osMemInit(void) +{ + next_request = (caddr_t)RtsFlags.GcFlags.heapBase; +} + +/* ----------------------------------------------------------------------------- + The mmap() method + + On Unix-like systems, we use mmap() to allocate our memory. We + want memory in chunks of MBLOCK_SIZE, and aligned on an MBLOCK_SIZE + boundary. The mmap() interface doesn't give us this level of + control, so we have to use some heuristics. + + In the general case, if we want a block of n megablocks, then we + allocate n+1 and trim off the slop from either side (using + munmap()) to get an aligned chunk of size n. However, the next + time we'll try to allocate directly after the previously allocated + chunk, on the grounds that this is aligned and likely to be free. + If it turns out that we were wrong, we have to munmap() and try + again using the general method. + + Note on posix_memalign(): this interface is available on recent + systems and appears to provide exactly what we want. However, it + turns out not to be as good as our mmap() implementation, because + it wastes extra space (using double the address space, in a test on + x86_64/Linux). The problem seems to be that posix_memalign() + returns memory that can be free()'d, so the library must store + extra information along with the allocated block, thus messing up + the alignment. Hence, we don't use posix_memalign() for now. + + -------------------------------------------------------------------------- */ -/* no C99 header stdint.h on OpenBSD? */ -#if defined(openbsd_HOST_OS) -typedef unsigned long my_uintptr_t; +// A wrapper around mmap(), to abstract away from OS differences in +// the mmap() interface. + +static void * +my_mmap (void *addr, lnat size) +{ + void *ret; + +#if defined(solaris2_HOST_OS) || defined(irix_HOST_OS) + { + int fd = open("/dev/zero",O_RDONLY); + ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + close(fd); + } +#elif hpux_HOST_OS + ret = mmap(addr, size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); +#elif darwin_HOST_OS + // Without MAP_FIXED, Apple's mmap ignores addr. + // With MAP_FIXED, it overwrites already mapped regions, whic + // mmap(0, ... MAP_FIXED ...) is worst of all: It unmaps the program text + // and replaces it with zeroes, causing instant death. + // This behaviour seems to be conformant with IEEE Std 1003.1-2001. + // Let's just use the underlying Mach Microkernel calls directly, + // they're much nicer. + + kern_return_t err = 0; + ret = addr; + if(addr) // try to allocate at adress + err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, FALSE); + if(!addr || err) // try to allocate anywhere + err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, TRUE); + + if(err) { + // don't know what the error codes mean exactly, assume it's + // not our problem though. + errorBelch("memory allocation failed (requested %lu bytes)", size); + stg_exit(EXIT_FAILURE); + } else { + vm_protect(mach_task_self(),(vm_address_t)ret,size,FALSE,VM_PROT_READ|VM_PROT_WRITE); + } #else -#include -typedef uintptr_t my_uintptr_t; + ret = mmap(addr, size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE, -1, 0); #endif + if (ret == (void *)-1) { + if (errno == ENOMEM || + (errno == EINVAL && sizeof(void*)==4 && size >= 0xc0000000)) { + // If we request more than 3Gig, then we get EINVAL + // instead of ENOMEM (at least on Linux). + errorBelch("out of memory (requested %lu bytes)", size); + stg_exit(EXIT_FAILURE); + } else { + barf("getMBlock: mmap: %s", strerror(errno)); + } + } + + return ret; +} + +// Implements the general case: allocate a chunk of memory of 'size' +// mblocks. + +static void * +gen_map_mblocks (lnat size) +{ + int slop; + StgWord8 *ret; + + // Try to map a larger block, and take the aligned portion from + // it (unmap the rest). + size += MBLOCK_SIZE; + ret = my_mmap(0, size); + + // unmap the slop bits around the chunk we allocated + slop = (W_)ret & MBLOCK_MASK; + + if (munmap(ret, MBLOCK_SIZE - slop) == -1) { + barf("gen_map_mblocks: munmap failed"); + } + if (slop > 0 && munmap(ret+size-slop, slop) == -1) { + barf("gen_map_mblocks: munmap failed"); + } + + // ToDo: if we happened to get an aligned block, then don't + // unmap the excess, just use it. For this to work, you + // need to keep in mind the following: + // * Calling my_mmap() with an 'addr' arg pointing to + // already my_mmap()ed space is OK and won't fail. + // * If my_mmap() can't satisfy the request at the + // given 'next_request' address in getMBlocks(), that + // you unmap the extra mblock mmap()ed here (or simply + // satisfy yourself that the slop introduced isn't worth + // salvaging.) + // + + // next time, try after the block we just got. + ret += MBLOCK_SIZE - slop; + return ret; +} + +void * +osGetMBlocks(nat n) +{ + caddr_t ret; + lnat size = MBLOCK_SIZE * (lnat)n; + + if (next_request == 0) { + // use gen_map_mblocks the first time. + ret = gen_map_mblocks(size); + } else { + ret = my_mmap(next_request, size); + + if (((W_)ret & MBLOCK_MASK) != 0) { + // misaligned block! +#if 0 // defined(DEBUG) + errorBelch("warning: getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request); +#endif + + // unmap this block... + if (munmap(ret, size) == -1) { + barf("getMBlock: munmap failed"); + } + // and do it the hard way + ret = gen_map_mblocks(size); + } + } + + // Next time, we'll try to allocate right after the block we just got. + // ToDo: check that we haven't already grabbed the memory at next_request + next_request = ret + size; + + return ret; +} + +void osFreeAllMBlocks(void) +{ + /* XXX Do something here (bug #711) */ +} + lnat getPageSize (void) { static lnat pageSize = 0; @@ -38,15 +228,15 @@ lnat getPageSize (void) void setExecutable (void *p, lnat len, rtsBool exec) { - my_uintptr_t pageSize = getPageSize(); + StgWord pageSize = getPageSize(); /* malloced memory isn't executable by default on OpenBSD */ - my_uintptr_t mask = ~(pageSize - 1); - my_uintptr_t startOfFirstPage = ((my_uintptr_t)p ) & mask; - my_uintptr_t startOfLastPage = ((my_uintptr_t)p + len - 1) & mask; - my_uintptr_t size = startOfLastPage - startOfFirstPage + pageSize; + StgWord mask = ~(pageSize - 1); + StgWord startOfFirstPage = ((StgWord)p ) & mask; + StgWord startOfLastPage = ((StgWord)p + len - 1) & mask; + StgWord size = startOfLastPage - startOfFirstPage + pageSize; if (mprotect((void*)startOfFirstPage, (size_t)size, (exec ? PROT_EXEC : 0) | PROT_READ | PROT_WRITE) != 0) { - barf("makeExecutable: failed to protect 0x%p\n", p); + barf("setExecutable: failed to protect 0x%p\n", p); } }