diff options
Diffstat (limited to 'erts/emulator/sys/common/erl_mseg.c')
| -rw-r--r-- | erts/emulator/sys/common/erl_mseg.c | 467 |
1 files changed, 460 insertions, 7 deletions
diff --git a/erts/emulator/sys/common/erl_mseg.c b/erts/emulator/sys/common/erl_mseg.c index f4e21bc05f..4a9bfd5d08 100644 --- a/erts/emulator/sys/common/erl_mseg.c +++ b/erts/emulator/sys/common/erl_mseg.c @@ -1,19 +1,19 @@ /* * %CopyrightBegin% - * - * Copyright Ericsson AB 2002-2009. All Rights Reserved. - * + * + * Copyright Ericsson AB 2002-2010. All Rights Reserved. + * * The contents of this file are subject to the Erlang Public License, * Version 1.1, (the "License"); you may not use this file except in * compliance with the License. You should have received a copy of the * Erlang Public License along with this software. If not, it can be * retrieved online at http://www.erlang.org/. - * + * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See * the License for the specific language governing rights and limitations * under the License. - * + * * %CopyrightEnd% */ @@ -83,10 +83,20 @@ static int is_cache_check_scheduled; static int is_cache_check_requested; #endif +#if HALFWORD_HEAP +static int initialize_pmmap(void); +static void *pmmap(size_t size); +static int pmunmap(void *p, size_t size); +static void *pmremap(void *old_address, size_t old_size, + size_t new_size); +#endif + #if HAVE_MMAP /* Mmap ... */ #define MMAP_PROT (PROT_READ|PROT_WRITE) + + #ifdef MAP_ANON # define MMAP_FLAGS (MAP_ANON|MAP_PRIVATE) # define MMAP_FD (-1) @@ -102,7 +112,11 @@ static int mmap_fd; # define HAVE_MSEG_RECREATE 0 #endif +#if HALFWORD_HEAP +#define CAN_PARTLY_DESTROY 0 +#else #define CAN_PARTLY_DESTROY 1 +#endif #else /* #if HAVE_MMAP */ #define CAN_PARTLY_DESTROY 0 #error "Not supported" @@ -232,6 +246,7 @@ static void thread_safe_init(void) { erts_mtx_init(&init_atoms_mutex, "mseg_init_atoms"); erts_mtx_init(&mseg_mutex, "mseg"); + #ifdef ERTS_THREADS_NO_SMP main_tid = erts_thr_self(); #endif @@ -306,10 +321,20 @@ mseg_create(Uint size) #if defined(ERTS_MSEG_FAKE_SEGMENTS) seg = erts_sys_alloc(ERTS_ALC_N_INVALID, NULL, size); #elif HAVE_MMAP +#if HALFWORD_HEAP + seg = pmmap(size); +#else seg = (void *) mmap((void *) 0, (size_t) size, MMAP_PROT, MMAP_FLAGS, MMAP_FD, 0); if (seg == (void *) MAP_FAILED) seg = NULL; +#endif +#if HALFWORD_HEAP + if ((unsigned long) seg & CHECK_POINTER_MASK) { + erts_fprintf(stderr,"Pointer mask failure (0x%08lx)\n",(unsigned long) seg); + return NULL; + } +#endif #else #error "Missing mseg_create() implementation" #endif @@ -329,9 +354,11 @@ mseg_destroy(void *seg, Uint size) #ifdef DEBUG int res = #endif - +#if HALFWORD_HEAP + pmunmap((void *) seg, size); +#else munmap((void *) seg, size); - +#endif ASSERT(size % page_size == 0); ASSERT(res == 0); #else @@ -355,12 +382,18 @@ mseg_recreate(void *old_seg, Uint old_size, Uint new_size) #if defined(ERTS_MSEG_FAKE_SEGMENTS) new_seg = erts_sys_realloc(ERTS_ALC_N_INVALID, NULL, old_seg, new_size); #elif HAVE_MREMAP +#if HALFWORD_HEAP + new_seg = (void *) pmremap((void *) old_seg, + (size_t) old_size, + (size_t) new_size); +#else new_seg = (void *) mremap((void *) old_seg, (size_t) old_size, (size_t) new_size, MREMAP_MAYMOVE); if (new_seg == (void *) MAP_FAILED) new_seg = NULL; +#endif #else #error "Missing mseg_recreate() implementation" #endif @@ -1328,6 +1361,10 @@ erts_mseg_init(ErtsMsegInit_t *init) erl_exit(ERTS_ABORT_EXIT, "erts_mseg: unable to open /dev/zero\n"); #endif +#if HAVE_MMAP && HALFWORD_HEAP + initialize_pmmap(); +#endif + page_size = GET_PAGE_SIZE; page_shift = 1; @@ -1450,3 +1487,419 @@ erts_mseg_test(unsigned long op, } +#if HALFWORD_HEAP +/* + * Very simple page oriented mmap replacer. Works in the lower + * 32 bit address range of a 64bit program. + * Implements anonymous mmap mremap and munmap with address order first fit. + * The free list is expected to be very short... + * To be used for compressed pointers in Erlang halfword emulator + * implementation. The MacOS X version is more of a toy, it's not really + * for production as the halfword erlang VM relies on Linux specific memory + * mapping tricks. + */ + +/*#define HARDDEBUG 1*/ + +#ifdef __APPLE__ +#define MAP_ANONYMOUS MAP_ANON +#endif + +#define INIT_LOCK() do {erts_mtx_init(&pmmap_mutex, "pmmap");} while(0) + +#define TAKE_LOCK() do {erts_mtx_lock(&pmmap_mutex);} while(0) + +#define RELEASE_LOCK() do {erts_mtx_unlock(&pmmap_mutex);} while(0) + +static erts_mtx_t pmmap_mutex; /* Also needed when !USE_THREADS */ + +typedef struct _free_block { + unsigned long num; /*pages*/ + struct _free_block *next; +} FreeBlock; + +/* Assigned once and for all */ +static size_t pagsz; + +/* Protect with lock */ +static FreeBlock *first; + +static size_t round_up_to_pagesize(size_t size) +{ + size_t x = size / pagsz; + + if ((size % pagsz)) { + ++x; + } + + return pagsz * x; +} + +static size_t round_down_to_pagesize(size_t size) +{ + size_t x = size / pagsz; + + return pagsz * x; +} + +static void *do_map(void *ptr, size_t sz) +{ + void *res; + + if (round_up_to_pagesize(sz) != sz) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld " + "does not map complete pages\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return NULL; + } + + if (((unsigned long) ptr) % pagsz) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld " + "is not page aligned\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return NULL; + } + + + res = mmap(ptr, sz, + PROT_READ | PROT_WRITE, MAP_PRIVATE | + MAP_ANONYMOUS | MAP_FIXED, + -1 , 0); + + if (res == MAP_FAILED) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld failed!\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return NULL; + } + + return res; +} + +static int do_unmap(void *ptr, size_t sz) +{ + void *res; + + if (round_up_to_pagesize(sz) != sz) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld " + "does not map complete pages\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return 1; + } + + if (((unsigned long) ptr) % pagsz) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld " + "is not page aligned\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return 1; + } + + + res = mmap(ptr, sz, + PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE + | MAP_FIXED, + -1 , 0); + + if (res == MAP_FAILED) { +#ifdef HARDDEBUG + fprintf(stderr,"Mapping of address %p with size %ld failed!\r\n", + (void *) ptr, (unsigned long) sz); +#endif + return 1; + } + + return 0; +} + +#ifdef __APPLE__ +/* + * The first 4 gig's are protected on Macos X for 64bit processes :( + * The range 0x1000000000 - 0x10FFFFFFFF is selected as an arbitrary + * value of a normally unused range... Real MMAP's will avoid + * it and all 32bit compressed pointers can be in that range... + * More expensive than on Linux where expansion of compressed + * poiters involves no masking (as they are in the first 4 gig's). + * It's also very uncertain if the MAP_NORESERVE flag really has + * any effect in MacOS X. Swap space may always be allocated... + */ +#define SET_RANGE_MIN() /* nothing */ +#define RANGE_MIN 0x1000000000UL +#define RANGE_MAX 0x1100000000UL +#define RANGE_MASK (RANGE_MIN) +#define EXTRA_MAP_FLAGS (MAP_FIXED) +#else +static size_t range_min; +#define SET_RANGE_MIN() do { range_min = (size_t) sbrk(0); } while (0) +#define RANGE_MIN range_min +#define RANGE_MAX 0x100000000UL +#define RANGE_MASK 0UL +#define EXTRA_MAP_FLAGS (0) +#endif + +static int initialize_pmmap(void) +{ + char *p,*q,*rptr; + size_t rsz; + FreeBlock *initial; + + + pagsz = getpagesize(); + SET_RANGE_MIN(); + if (sizeof(void *) != 8) { + erl_exit(1,"Halfword emulator cannot be run in 32bit mode"); + } + + p = (char *) RANGE_MIN; + q = (char *) RANGE_MAX; + + rsz = round_down_to_pagesize(q - p); + + rptr = mmap((void *) p, rsz, + PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | + MAP_NORESERVE | EXTRA_MAP_FLAGS, + -1 , 0); +#ifdef HARDDEBUG + printf("rsz = %ld, pages = %ld, rptr = %p\r\n", + (unsigned long) rsz, (unsigned long) (rsz / pagsz), + (void *) rptr); +#endif + if (!do_map(rptr,pagsz)) { + erl_exit(1,"Could not actually mmap first page for halfword emulator...\n"); + } + initial = (FreeBlock *) rptr; + initial->num = (rsz / pagsz); + initial->next = NULL; + first = initial; + INIT_LOCK(); + return 0; +} + +#ifdef HARDDEBUG +static void dump_freelist(void) +{ + FreeBlock *p = first; + + while (p) { + printf("p = %p\r\np->num = %ld\r\np->next = %p\r\n\r\n", + (void *) p, (unsigned long) p->num, (void *) p->next); + p = p->next; + } +} +#endif + + +static void *pmmap(size_t size) +{ + size_t real_size = round_up_to_pagesize(size); + size_t num_pages = real_size / pagsz; + FreeBlock **block; + FreeBlock *tail; + FreeBlock *res; + TAKE_LOCK(); + for (block = &first; + *block != NULL && (*block)->num < num_pages; + block = &((*block)->next)) + ; + if (!(*block)) { + RELEASE_LOCK(); + return NULL; + } + if ((*block)->num == num_pages) { + /* nice, perfect fit */ + res = *block; + *block = (*block)->next; + } else { + tail = (FreeBlock *) (((char *) ((void *) (*block))) + real_size); + if (!do_map(tail,pagsz)) { +#ifdef HARDDEBUG + fprintf(stderr, "Could not actually allocate page at %p...\r\n", + (void *) tail); +#endif + RELEASE_LOCK(); + return NULL; + } + tail->num = (*block)->num - num_pages; + tail->next = (*block)->next; + res = *block; + *block = tail; + } + RELEASE_LOCK(); + if (!do_map(res,real_size)) { +#ifdef HARDDEBUG + fprintf(stderr, "Could not actually allocate %ld at %p...\r\n", + (unsigned long) real_size, (void *) res); +#endif + return NULL; + } + + return (void *) res; +} + +static int pmunmap(void *p, size_t size) +{ + size_t real_size = round_up_to_pagesize(size); + size_t num_pages = real_size / pagsz; + FreeBlock *block; + FreeBlock *last; + FreeBlock *nb = (FreeBlock *) p; + + if (real_size > pagsz) { + if (do_unmap(((char *) p) + pagsz,real_size - pagsz)) { + return 1; + } + } + + TAKE_LOCK(); + + last = NULL; + block = first; + while(block != NULL && ((void *) block) < p) { + last = block; + block = block->next; + } + + if (block != NULL && + ((void *) block) == ((void *) (((char *) p) + real_size))) { + /* Merge new free block with following */ + nb->num = block->num + num_pages; + nb->next = block->next; + if (do_unmap(block,pagsz)) { + RELEASE_LOCK(); + return 1; + } + } else { + /* just link in */ + nb->num = num_pages; + nb->next = block; + } + if (last != NULL) { + if (p == ((void *) (((char *) last) + (last->num * pagsz)))) { + /* Merge with previous */ + last->num += nb->num; + last->next = nb->next; + if (do_unmap(nb,pagsz)) { + RELEASE_LOCK(); + return 1; + } + } else { + last->next = nb; + } + } else { + first = nb; + } + RELEASE_LOCK(); + return 0; +} + +static void *pmremap(void *old_address, size_t old_size, + size_t new_size) +{ + size_t new_real_size = round_up_to_pagesize(new_size); + size_t new_num_pages = new_real_size / pagsz; + size_t old_real_size = round_up_to_pagesize(old_size); + size_t old_num_pages = old_real_size / pagsz; + if (new_num_pages == old_num_pages) { + return old_address; + } else if (new_num_pages < old_num_pages) { /* Shrink */ + size_t nfb_pages = old_num_pages - new_num_pages; + size_t nfb_real_size = old_real_size - new_real_size; + void *vnfb = (void *) (((char *)old_address) + new_real_size); + FreeBlock *nfb = (FreeBlock *) vnfb; + FreeBlock **block; + TAKE_LOCK(); + for (block = &first; + *block != NULL && (*block) < nfb; + block = &((*block)->next)) + ; + if (!(*block) || + (*block) > ((FreeBlock *)(((char *) vnfb) + nfb_real_size))) { + /* Normal link in */ + if (nfb_pages > 1) { + if (do_unmap((void *)(((char *) vnfb) + pagsz), + (nfb_pages - 1)*pagsz)) { + return NULL; + } + } + nfb->next = (*block); + nfb->num = nfb_pages; + (*block) = nfb; + } else { /* block merge */ + nfb->next = (*block)->next; + nfb->num = nfb_pages + (*block)->num; + /* unmap also the first page of the next freeblock */ + (*block) = nfb; + if (do_unmap((void *)(((char *) vnfb) + pagsz), + nfb_pages*pagsz)) { + return NULL; + } + } + RELEASE_LOCK(); + return old_address; + } else { /* Enlarge */ + FreeBlock **block; + void *old_end = (void *) (((char *)old_address) + old_real_size); + TAKE_LOCK(); + for (block = &first; + *block != NULL && (*block) < (FreeBlock *) old_address; + block = &((*block)->next)) + ; + if ((*block) == NULL || old_end > ((void *) RANGE_MAX) || + (*block) != old_end || + (*block)->num < (new_num_pages - old_num_pages)) { + /* cannot extend */ + void *result; + RELEASE_LOCK(); + result = pmmap(new_size); + if (result == NULL) { + return NULL; + } + memcpy(result,old_address,old_size); + if (pmunmap(old_address,old_size)) { + /* Oups... */ + pmunmap(result,new_size); + return NULL; + } + return result; + } else { /* extend */ + size_t remaining_pages = (*block)->num - + (new_num_pages - old_num_pages); + if (!remaining_pages) { + void *p = (void *) (((char *) (*block)) + pagsz); + void *n = (*block)->next; + size_t x = ((*block)->num - 1) * pagsz; + if (x > 0) { + if (do_map(p,x) == NULL) { + RELEASE_LOCK(); + return NULL; + } + } + (*block) = n; + } else { + FreeBlock *nfb = (FreeBlock *) ((void *) + (((char *) old_address) + + new_real_size)); + void *p = (void *) (((char *) (*block)) + pagsz); + if (do_map(p,new_real_size - old_real_size) == NULL) { + RELEASE_LOCK(); + return NULL; + } + nfb->num = remaining_pages; + nfb->next = (*block)->next; + (*block) = nfb; + } + RELEASE_LOCK(); + return old_address; + } + } +} + +#endif /* HALFWORD_HEAP */ |