mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-07-02 17:28:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Reduce stack virtual memory consumption on Linux

Browse source
This commit is contained in:
Justine Tunney 2024-12-25 19:43:43 -08:00
parent cc8a9eb93c
commit 36e5861b0c
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
31 changed files with 583 additions and 166 deletions
Download patch file Download diff file Expand all files Collapse all files

48
libc/intrin/mmap.c
View file

@ -85,7 +85,8 @@ privileged optimizespeed struct Map *__maps_floor(const char *addr) {
return 0;
}
static bool __maps_overlaps(const char *addr, size_t size, int pagesz) {
static bool __maps_overlaps(const char *addr, size_t size) {
int pagesz = __pagesize;
struct Map *map, *floor = __maps_floor(addr);
for (map = floor; map && map->addr <= addr + size; map = __maps_next(map))
if (MAX(addr, map->addr) <
@ -305,27 +306,39 @@ void __maps_insert(struct Map *map) {
}
static void __maps_track_insert(struct Map *map, char *addr, size_t size,
uintptr_t map_handle) {
uintptr_t map_handle, int prot, int flags) {
map->addr = addr;
map->size = size;
map->prot = PROT_READ | PROT_WRITE;
map->flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NOFORK;
map->prot = prot;
map->flags = flags;
map->hand = map_handle;
__maps_lock();
ASSERT(!__maps_overlaps(addr, size));
__maps_insert(map);
__maps_unlock();
}
bool __maps_track(char *addr, size_t size) {
// adds interval to rbtree (no sys_mmap)
bool __maps_track(char *addr, size_t size, int prot, int flags) {
struct Map *map;
do {
if (!(map = __maps_alloc()))
return false;
} while (map == MAPS_RETRY);
__maps_track_insert(map, addr, size, -1);
__maps_track_insert(map, addr, size, -1, prot, flags);
return true;
}
// removes interval from rbtree (no sys_munmap)
int __maps_untrack(char *addr, size_t size) {
struct Map *deleted = 0;
__maps_lock();
int rc = __muntrack(addr, size, __pagesize, &deleted);
__maps_unlock();
__maps_free_all(deleted);
return rc;
}
struct Map *__maps_alloc(void) {
struct Map *map;
uintptr_t tip = atomic_load_explicit(&__maps.freed, memory_order_relaxed);
@ -342,7 +355,9 @@ struct Map *__maps_alloc(void) {
if (sys.addr == MAP_FAILED)
return 0;
map = sys.addr;
__maps_track_insert(map, sys.addr, gransz, sys.maphandle);
__maps_track_insert(map, sys.addr, gransz, sys.maphandle,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NOFORK);
for (int i = 1; i < gransz / sizeof(struct Map); ++i)
__maps_free(map + i);
return MAPS_RETRY;
@ -370,7 +385,7 @@ static int __munmap(char *addr, size_t size) {
size_t pgup_size = (size + pagesz - 1) & -pagesz;
size_t grup_size = (size + gransz - 1) & -gransz;
if (grup_size > pgup_size)
if (__maps_overlaps(addr + pgup_size, grup_size - pgup_size, pagesz)) {
if (__maps_overlaps(addr + pgup_size, grup_size - pgup_size)) {
__maps_unlock();
return einval();
}
@ -420,7 +435,7 @@ static void *__maps_pickaddr(size_t size) {
__maps.pick = 0;
if (!addr)
addr = __maps_randaddr();
if (!__maps_overlaps(addr, size, __pagesize)) {
if (!__maps_overlaps(addr, size)) {
__maps.pick = addr + ((size + __gransize - 1) & -__gransize);
__maps_unlock();
return addr;
@ -455,7 +470,7 @@ static void *__mmap_chunk(void *addr, size_t size, int prot, int flags, int fd,
sysflags |= MAP_FIXED_NOREPLACE_linux;
} else if (IsFreebsd() || IsNetbsd()) {
sysflags |= MAP_FIXED;
if (__maps_overlaps(addr, size, pagesz)) {
if (__maps_overlaps(addr, size)) {
__maps_free(map);
return (void *)eexist();
}
@ -508,11 +523,8 @@ TryAgain:
}
// untrack mapping we blew away
if (!IsWindows() && should_untrack) {
struct Map *deleted = 0;
__muntrack(res.addr, size, pagesz, &deleted);
__maps_free_all(deleted);
}
if (!IsWindows() && should_untrack)
__maps_untrack(res.addr, size);
// track map object
map->addr = res.addr;
@ -599,8 +611,8 @@ static void *__mremap_impl(char *old_addr, size_t old_size, size_t new_size,
size_t pgup_old_size = (old_size + pagesz - 1) & -pagesz;
size_t grup_old_size = (old_size + gransz - 1) & -gransz;
if (grup_old_size > pgup_old_size)
if (__maps_overlaps(old_addr + pgup_old_size, grup_old_size - pgup_old_size,
pagesz))
if (__maps_overlaps(old_addr + pgup_old_size,
grup_old_size - pgup_old_size))
return (void *)einval();
old_size = pgup_old_size;
@ -611,7 +623,7 @@ static void *__mremap_impl(char *old_addr, size_t old_size, size_t new_size,
size_t grup_new_size = (new_size + gransz - 1) & -gransz;
if (grup_new_size > pgup_new_size)
if (__maps_overlaps(new_addr + pgup_new_size,
grup_new_size - pgup_new_size, pagesz))
grup_new_size - pgup_new_size))
return (void *)einval();
}