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use 1GiB huge pages on windows when reserving upfront

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This commit is contained in:
daan 2019-08-19 18:16:12 -07:00
parent 0e639addb0
commit a8b24472cb
2 changed files with 81 additions and 55 deletions
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110
src/os.c
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@ -84,11 +84,13 @@ static size_t mi_os_good_alloc_size(size_t size, size_t alignment) {
#if defined(_WIN32)
// We use VirtualAlloc2 for aligned allocation, but it is only supported on Windows 10 and Windows Server 2016.
// So, we need to look it up dynamically to run on older systems. (use __stdcall for 32-bit compatibility)
// Same for DiscardVirtualMemory. (hide MEM_EXTENDED_PARAMETER to compile with older SDK's)
typedef PVOID(__stdcall *PVirtualAlloc2)(HANDLE, PVOID, SIZE_T, ULONG, ULONG, /* MEM_EXTENDED_PARAMETER* */ void*, ULONG);
typedef DWORD(__stdcall *PDiscardVirtualMemory)(PVOID,SIZE_T);
// NtAllocateVirtualAllocEx is used for huge OS page allocation (1GiB)
// We hide MEM_EXTENDED_PARAMETER to compile with older SDK's.
#include <winternl.h>
typedef PVOID (__stdcall *PVirtualAlloc2)(HANDLE, PVOID, SIZE_T, ULONG, ULONG, /* MEM_EXTENDED_PARAMETER* */ void*, ULONG);
typedef NTSTATUS (__stdcall *PNtAllocateVirtualMemoryEx)(HANDLE, PVOID*, SIZE_T*, ULONG, ULONG, /* MEM_EXTENDED_PARAMETER* */ PVOID, ULONG);
static PVirtualAlloc2 pVirtualAlloc2 = NULL;
static PDiscardVirtualMemory pDiscardVirtualMemory = NULL;
static PNtAllocateVirtualMemoryEx pNtAllocateVirtualMemoryEx = NULL;
void _mi_os_init(void) {
// get the page size
@ -103,7 +105,11 @@ void _mi_os_init(void) {
// use VirtualAlloc2FromApp if possible as it is available to Windows store apps
pVirtualAlloc2 = (PVirtualAlloc2)GetProcAddress(hDll, "VirtualAlloc2FromApp");
if (pVirtualAlloc2==NULL) pVirtualAlloc2 = (PVirtualAlloc2)GetProcAddress(hDll, "VirtualAlloc2");
pDiscardVirtualMemory = (PDiscardVirtualMemory)GetProcAddress(hDll, "DiscardVirtualMemory");
FreeLibrary(hDll);
}
hDll = LoadLibrary(TEXT("ntdll.dll"));
if (hDll != NULL) {
pNtAllocateVirtualMemoryEx = (PNtAllocateVirtualMemoryEx)GetProcAddress(hDll, "NtAllocateVirtualMemoryEx");
FreeLibrary(hDll);
}
// Try to see if large OS pages are supported
@ -188,25 +194,46 @@ static bool mi_os_mem_free(void* addr, size_t size, mi_stats_t* stats)
#ifdef _WIN32
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 NtAllocateVirtualMemoryEx for 1GiB huge pages
if ((size % (uintptr_t)1 << 20) == 0 /* 1GiB multiple */
&& (flags & MEM_LARGE_PAGES) != 0 && (flags & MEM_COMMIT) != 0
&& (addr != NULL || try_alignment == 0 || try_alignment % _mi_os_page_size() == 0)
&& pNtAllocateVirtualMemoryEx != NULL)
{
#ifndef MEM_EXTENDED_PARAMETER_NONPAGED_HUGE
#define MEM_EXTENDED_PARAMETER_NONPAGED_HUGE (0x10)
#endif
MEM_EXTENDED_PARAMETER param = { 0, 0 };
param.Type = 5; // == MemExtendedParameterAttributeFlags;
param.ULong64 = MEM_EXTENDED_PARAMETER_NONPAGED_HUGE;
SIZE_T psize = size;
void* base = addr;
NTSTATUS err = (*pNtAllocateVirtualMemoryEx)(GetCurrentProcess(), &base, &psize, flags | MEM_RESERVE, PAGE_READWRITE, &param, 1);
if (err == 0) {
return base;
}
// else fall back to regular large OS pages
}
// on modern Windows try use VirtualAlloc2 for aligned allocation
if (try_alignment > 0 && (try_alignment % _mi_os_page_size()) == 0 && pVirtualAlloc2 != NULL) {
MEM_ADDRESS_REQUIREMENTS reqs = { 0 };
reqs.Alignment = try_alignment;
MEM_EXTENDED_PARAMETER param = { 0 };
param.Type = MemExtendedParameterAddressRequirements;
param.Pointer = &reqs;
return (*pVirtualAlloc2)(addr, NULL, size, flags, PAGE_READWRITE, &param, 1);
return (*pVirtualAlloc2)(GetCurrentProcess(), addr, size, flags, PAGE_READWRITE, &param, 1);
}
#endif
return VirtualAlloc(addr, size, flags, PAGE_READWRITE);
}
static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment, DWORD flags) {
static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment, DWORD flags, bool large_only) {
static volatile uintptr_t large_page_try_ok = 0;
void* p = NULL;
if (use_large_os_page(size, try_alignment)) {
if (large_only || use_large_os_page(size, try_alignment)) {
uintptr_t try_ok = mi_atomic_read(&large_page_try_ok);
if (try_ok > 0) {
if (!large_only && try_ok > 0) {
// if a large 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.
mi_atomic_compare_exchange(&large_page_try_ok, try_ok - 1, try_ok);
@ -214,6 +241,7 @@ static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment,
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);
if (large_only) return p;
// fall back to non-large page allocation on error (`p == NULL`).
if (p == NULL) {
mi_atomic_write(&large_page_try_ok,10); // on error, don't try again for the next N allocations
@ -261,7 +289,7 @@ static void* mi_unix_mmapx(void* addr, size_t size, size_t try_alignment, int pr
return p;
}
static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags) {
static void* mi_unix_mmap(void* addr, size_t size, size_t try_alignment, int protect_flags, bool large_only) {
void* p = NULL;
#if !defined(MAP_ANONYMOUS)
#define MAP_ANONYMOUS MAP_ANON
@ -283,10 +311,10 @@ static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags)
// macOS: tracking anonymous page with a specific ID. (All up to 98 are taken officially but LLVM sanitizers had taken 99)
fd = VM_MAKE_TAG(100);
#endif
if (use_large_os_page(size, try_alignment)) {
if (large_only || use_large_os_page(size, try_alignment)) {
static volatile uintptr_t large_page_try_ok = 0;
uintptr_t try_ok = mi_atomic_read(&large_page_try_ok);
if (try_ok > 0) {
if (!large_only && try_ok > 0) {
// If the OS is not configured for large OS pages, or the user does not have
// enough permission, the `mmap` will always fail (but it might also fail for other reasons).
// Therefore, once a large page allocation failed, we don't try again for `large_page_try_ok` times
@ -302,15 +330,24 @@ static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags)
#ifdef MAP_HUGETLB
lflags |= MAP_HUGETLB;
#endif
#ifdef MAP_HUGE_1GB
if ((size % (uintptr_t)1 << 20) == 0) {
lflags |= MAP_HUGE_1GB;
}
else
#endif
{
#ifdef MAP_HUGE_2MB
lflags |= MAP_HUGE_2MB;
#endif
}
#ifdef VM_FLAGS_SUPERPAGE_SIZE_2MB
lfd |= VM_FLAGS_SUPERPAGE_SIZE_2MB;
#endif
if (lflags != flags) {
if (large_only || lflags != flags) {
// try large OS page allocation
p = mi_unix_mmapx(NULL, size, try_alignment, protect_flags, lflags, lfd);
p = mi_unix_mmapx(addr, size, try_alignment, protect_flags, lflags, lfd);
if (large_only) return p;
if (p == NULL) {
mi_atomic_write(&large_page_try_ok, 10); // on error, don't try again for the next N allocations
}
@ -318,7 +355,7 @@ static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags)
}
}
if (p == NULL) {
p = mi_unix_mmapx(NULL,size, try_alignment, protect_flags, flags, fd);
p = mi_unix_mmapx(addr, size, try_alignment, protect_flags, flags, fd);
#if defined(MADV_HUGEPAGE)
// Many Linux systems don't allow MAP_HUGETLB but they support instead
// transparent huge pages (TPH). It is not required to call `madvise` with MADV_HUGE
@ -341,18 +378,18 @@ static void* mi_os_mem_alloc(size_t size, size_t try_alignment, bool commit, mi_
mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0);
if (size == 0) return NULL;
void* p = mi_os_alloc_from_huge_reserved(size,try_alignment,commit);
void* p = mi_os_alloc_from_huge_reserved(size, try_alignment, commit);
if (p != NULL) return p;
#if defined(_WIN32)
int flags = MEM_RESERVE;
if (commit) flags |= MEM_COMMIT;
p = mi_win_virtual_alloc(NULL, size, try_alignment, flags);
p = mi_win_virtual_alloc(NULL, size, try_alignment, flags, false);
#elif defined(__wasi__)
p = mi_wasm_heap_grow(size, try_alignment);
#else
int protect_flags = (commit ? (PROT_WRITE | PROT_READ) : PROT_NONE);
p = mi_unix_mmap(size, try_alignment, protect_flags);
p = mi_unix_mmap(NULL, size, try_alignment, protect_flags, false);
#endif
_mi_stat_increase(&stats->mmap_calls, 1);
if (p != NULL) {
@ -402,7 +439,7 @@ static void* mi_os_mem_alloc_aligned(size_t size, size_t alignment, bool commit,
// otherwise free and allocate at an aligned address in there
mi_os_mem_free(p, over_size, stats);
void* aligned_p = mi_align_up_ptr(p, alignment);
p = mi_win_virtual_alloc(aligned_p, size, alignment, flags);
p = mi_win_virtual_alloc(aligned_p, size, alignment, flags, false);
if (p == aligned_p) break; // success!
if (p != NULL) { // should not happen?
mi_os_mem_free(p, size, stats);
@ -557,18 +594,9 @@ static bool mi_os_resetx(void* addr, size_t size, bool reset, mi_stats_t* stats)
#endif
#if defined(_WIN32)
// Testing shows that for us (on `malloc-large`) MEM_RESET is 2x faster than DiscardVirtualMemory
// (but this is for an access pattern that immediately reuses the memory)
if (mi_option_is_enabled(mi_option_reset_discards) && pDiscardVirtualMemory != NULL) {
DWORD ok = (*pDiscardVirtualMemory)(start, csize);
mi_assert_internal(ok == ERROR_SUCCESS);
if (ok != ERROR_SUCCESS) return false;
}
else {
void* p = VirtualAlloc(start, csize, MEM_RESET, PAGE_READWRITE);
mi_assert_internal(p == start);
if (p != start) return false;
}
#else
#if defined(MADV_FREE)
static int advice = MADV_FREE;
@ -736,6 +764,7 @@ int mi_reserve_huge_os_pages( size_t pages, double max_secs ) mi_attr_noexcept
{
if (max_secs==0) return -1; // timeout
if (pages==0) return 0; // ok
if (os_huge_reserved.start != NULL) return -2; // already reserved
// Allocate one page at the time but try to place them contiguously
// We allocate one page at the time to be able to abort if it takes too long
@ -743,23 +772,20 @@ int mi_reserve_huge_os_pages( size_t pages, double max_secs ) mi_attr_noexcept
uint8_t* start = (uint8_t*)((uintptr_t)1 << 43); // 8TiB virtual start address
uint8_t* addr = start; // current top of the allocations
for (size_t page = 0; page < pages; page++, addr += MI_HUGE_OS_PAGE_SIZE ) {
// allocate lorgu pages
void* p = NULL;
// OS specific calls to allocate huge OS pages
#ifdef _WIN32
p = mi_win_virtual_allocx(addr, MI_HUGE_OS_PAGE_SIZE, 0, MEM_LARGE_PAGES | MEM_COMMIT | MEM_RESERVE);
#elif defined(MI_OS_USE_MMAP) && defined(MAP_HUGETLB)
int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB;
#ifdef MAP_HUGE_1GB
flags |= MAP_HUGE_1GB
#elif defined(MAP_HUGE_2MB)
flags |= MAP_HUGE_2MB;
#endif
p = mi_unix_mmapx(addr, MI_HUGE_OS_PAGE_SIZE, 0, PROT_WRITE|PROT_READ, flags, -1);
p = mi_win_virtual_alloc(addr, MI_HUGE_OS_PAGE_SIZE, 0, MEM_LARGE_PAGES | MEM_COMMIT | MEM_RESERVE, true);
#elif defined(MI_OS_USE_MMAP)
p = mi_unix_mmap(addr, MI_HUGE_OS_PAGE_SIZE, 0, PROT_READ | PROT_WRITE, true);
#else
// always fail
#endif
// Did we succeed at a contiguous address?
if (p != addr) {
if (p != NULL) {
_mi_warning_message("could not allocate contiguous huge page at 0x%p\n", addr);
_mi_warning_message("could not allocate contiguous huge page %zu at 0x%p\n", page, addr);
_mi_os_free(p, MI_HUGE_OS_PAGE_SIZE, &_mi_stats_main );
}
else {
@ -768,7 +794,7 @@ int mi_reserve_huge_os_pages( size_t pages, double max_secs ) mi_attr_noexcept
#else
int err = errno;
#endif
_mi_warning_message("could not allocate huge page at 0x%p, error: %i\n", addr, err);
_mi_warning_message("could not allocate huge page %zu at 0x%p, error: %i\n", page, addr, err);
}
return -2;
}
@ -777,8 +803,8 @@ int mi_reserve_huge_os_pages( size_t pages, double max_secs ) mi_attr_noexcept
os_huge_reserved.start = addr;
}
os_huge_reserved.reserved += MI_HUGE_OS_PAGE_SIZE;
_mi_stat_increase(&_mi_stats_main.reserved, MI_HUGE_OS_PAGE_SIZE );
_mi_stat_increase(&_mi_stats_main.committed, MI_HUGE_OS_PAGE_SIZE);
_mi_stat_increase(&_mi_stats_main.reserved, MI_HUGE_OS_PAGE_SIZE);
// check for timeout
double elapsed = _mi_clock_end(start_t);

4
test/test-stress.c
View File

@ -154,8 +154,8 @@ int main(int argc, char** argv) {
if (n > 0) N = n;
}
printf("start with %i threads with a %i%% load-per-thread\n", THREADS, N);
int res = mi_reserve_huge_os_pages(4,1);
printf("(reserve huge: %i\n)", res);
//int res = mi_reserve_huge_os_pages(4,1);
//printf("(reserve huge: %i\n)", res);
//bench_start_program();
memset((void*)transfer, 0, TRANSFERS*sizeof(void*));