always pass commit flag to large page allocation on windows
@@ -175,7 +175,7 @@ static bool mi_os_mem_free(void* addr, size_t size, mi_stats_t* stats)
static void* mi_win_virtual_allocx(void* addr, size_t size, size_t try_alignment, DWORD flags) {
#if defined(MEM_EXTENDED_PARAMETER_TYPE_BITS)
if (try_alignment > 0 && (try_alignment % _mi_os_page_size()) == 0 && pVirtualAlloc2 != NULL) {
- // on modern Windows try use VirtualAlloc2
+ // on modern Windows try use VirtualAlloc2 for aligned allocation
MEM_ADDRESS_REQUIREMENTS reqs = { 0 };
reqs.Alignment = try_alignment;
MEM_EXTENDED_PARAMETER param = { 0 };
@@ -188,10 +188,22 @@ static void* mi_win_virtual_allocx(void* addr, size_t size, size_t try_alignment
}
static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment, DWORD flags) {
+ static size_t large_page_try_ok = 0;
void* p = NULL;
if (use_large_os_page(size, try_alignment)) {
- p = mi_win_virtual_allocx(addr, size, try_alignment, MEM_LARGE_PAGES | flags);
+ if (large_page_try_ok > 0) {
+ // if a large page page allocation fails, it seems the calls to VirtualAlloc get very expensive.
+ // therefore, once a large page allocation failed, we don't try again for `large_page_try_ok` times.
+ large_page_try_ok--;
+ }
+ else {
+ // large OS pages must always reserve and commit.
+ p = mi_win_virtual_allocx(addr, size, try_alignment, MEM_LARGE_PAGES | MEM_COMMIT | MEM_RESERVE | flags);
// fall back to non-large page allocation on error (`p == NULL`).
+ if (p == NULL) {
+ large_page_try_ok = 10; // on error, don't try again for the next N allocations
+ }
+ }
}
if (p == NULL) {
p = mi_win_virtual_allocx(addr, size, try_alignment, flags);
