aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/sys/common/erl_mseg.c
diff options
context:
space:
mode:
Diffstat (limited to 'erts/emulator/sys/common/erl_mseg.c')
-rw-r--r--erts/emulator/sys/common/erl_mseg.c470
1 files changed, 448 insertions, 22 deletions
diff --git a/erts/emulator/sys/common/erl_mseg.c b/erts/emulator/sys/common/erl_mseg.c
index c859b192f7..747c2e2a80 100644
--- a/erts/emulator/sys/common/erl_mseg.c
+++ b/erts/emulator/sys/common/erl_mseg.c
@@ -83,6 +83,14 @@ 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 ... */
@@ -113,7 +121,11 @@ 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"
@@ -243,6 +255,7 @@ 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
@@ -317,10 +330,14 @@ 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);
@@ -346,9 +363,11 @@ 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
@@ -372,12 +391,18 @@ 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
@@ -1325,27 +1350,10 @@ erts_mseg_unit_size(void)
#endif
static void halfword_reserve(void)
{
-#if 0
- void *ptr, *understack;
- unsigned long x = 0x80000000;
- long i = 0;
-
- understack = mmap(NULL,GET_PAGE_SIZE, PROT_NONE, RESERVE_FLAGS,
- MMAP_FD, 0);
- while (x < (unsigned long) understack) {
- ptr = mmap((void *) x, GET_PAGE_SIZE, PROT_NONE, RESERVE_FLAGS,
- MMAP_FD, 0);
- if ((unsigned long) ptr < 0x80000000) {
- munmap(ptr, GET_PAGE_SIZE);
- } else {
- ++i;
- }
- x += GET_PAGE_SIZE;
- }
- erts_fprintf(stderr,"Reserved %ld pages [%d MB]...\n",i, (i*GET_PAGE_SIZE)/1024/1024);
-#else
- return;
+#if HALFWORD_HEAP
+ initialize_pmmap();
#endif
+ return;
}
#endif
@@ -1502,3 +1510,421 @@ 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;
+ //fprintf(stderr,"***** %p,%p,%ld,%p\n",res,*block,num_pages,first);
+ //dump_freelist();
+ } 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 */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 17:34:24 +0000