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bpo-44337: Shrink the LOAD_ATTR/STORE_ATTR caches (GH-31517)

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Brandt Bucher 2022-02-23 10:53:24 -08:00 committed by GitHub
parent 78859e58e4
commit 281ea9c391
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4 changed files with 36 additions and 43 deletions
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2
Include/internal/pycore_code.h
View file

@ -23,7 +23,7 @@ typedef struct {
typedef struct {
uint32_t tp_version;
uint32_t dk_version_or_hint;
uint32_t dk_version;
} _PyAttrCache;
typedef struct {

2
Misc/NEWS.d/next/Core and Builtins/2022-02-22-17-19-45.bpo-44337.XA-egu.rst Normal file
View file

@ -0,0 +1,2 @@
Reduce the memory usage of specialized :opcode:`LOAD_ATTR` and
:opcode:`STORE_ATTR` instructions.

39
Python/ceval.c
View file

@ -1450,11 +1450,10 @@ eval_frame_handle_pending(PyThreadState *tstate)
#define LOAD_MODULE_ATTR_OR_METHOD(attr_or_method) \
SpecializedCacheEntry *caches = GET_CACHE(); \
_PyAdaptiveEntry *cache0 = &caches[0].adaptive; \
_PyAttrCache *cache1 = &caches[-1].attr; \
DEOPT_IF(!PyModule_CheckExact(owner), LOAD_##attr_or_method); \
PyDictObject *dict = (PyDictObject *)((PyModuleObject *)owner)->md_dict; \
assert(dict != NULL); \
DEOPT_IF(dict->ma_keys->dk_version != cache1->dk_version_or_hint, \
DEOPT_IF(dict->ma_keys->dk_version != cache0->version, \
LOAD_##attr_or_method); \
assert(dict->ma_keys->dk_kind == DICT_KEYS_UNICODE); \
assert(cache0->index < dict->ma_keys->dk_nentries); \
@ -3452,9 +3451,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, LOAD_ATTR);
assert(tp->tp_dictoffset < 0);
assert(tp->tp_flags & Py_TPFLAGS_MANAGED_DICT);
PyDictValues *values = *_PyObject_ValuesPointer(owner);
@ -3486,15 +3484,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, LOAD_ATTR);
assert(tp->tp_flags & Py_TPFLAGS_MANAGED_DICT);
PyDictObject *dict = *(PyDictObject **)_PyObject_ManagedDictPointer(owner);
DEOPT_IF(dict == NULL, LOAD_ATTR);
assert(PyDict_CheckExact((PyObject *)dict));
PyObject *name = GETITEM(names, cache0->original_oparg);
uint32_t hint = cache1->dk_version_or_hint;
uint16_t hint = cache0->index;
DEOPT_IF(hint >= (size_t)dict->ma_keys->dk_nentries, LOAD_ATTR);
PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + hint;
DEOPT_IF(ep->me_key != name, LOAD_ATTR);
@ -3514,9 +3511,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, LOAD_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, LOAD_ATTR);
char *addr = (char *)owner + cache0->index;
res = *(PyObject **)addr;
DEOPT_IF(res == NULL, LOAD_ATTR);
@ -3553,9 +3549,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, STORE_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, STORE_ATTR);
assert(tp->tp_flags & Py_TPFLAGS_MANAGED_DICT);
PyDictValues *values = *_PyObject_ValuesPointer(owner);
DEOPT_IF(values == NULL, STORE_ATTR);
@ -3581,15 +3576,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, STORE_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, STORE_ATTR);
assert(tp->tp_flags & Py_TPFLAGS_MANAGED_DICT);
PyDictObject *dict = *(PyDictObject **)_PyObject_ManagedDictPointer(owner);
DEOPT_IF(dict == NULL, STORE_ATTR);
assert(PyDict_CheckExact((PyObject *)dict));
PyObject *name = GETITEM(names, cache0->original_oparg);
uint32_t hint = cache1->dk_version_or_hint;
uint16_t hint = cache0->index;
DEOPT_IF(hint >= (size_t)dict->ma_keys->dk_nentries, STORE_ATTR);
PyDictKeyEntry *ep = DK_ENTRIES(dict->ma_keys) + hint;
DEOPT_IF(ep->me_key != name, STORE_ATTR);
@ -3616,9 +3610,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
PyTypeObject *tp = Py_TYPE(owner);
SpecializedCacheEntry *caches = GET_CACHE();
_PyAdaptiveEntry *cache0 = &caches[0].adaptive;
_PyAttrCache *cache1 = &caches[-1].attr;
assert(cache1->tp_version != 0);
DEOPT_IF(tp->tp_version_tag != cache1->tp_version, STORE_ATTR);
assert(cache0->version != 0);
DEOPT_IF(tp->tp_version_tag != cache0->version, STORE_ATTR);
char *addr = (char *)owner + cache0->index;
STAT_INC(STORE_ATTR, hit);
STACK_SHRINK(1);
@ -4416,7 +4409,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
assert(self_cls->tp_flags & Py_TPFLAGS_MANAGED_DICT);
PyDictObject *dict = *(PyDictObject**)_PyObject_ManagedDictPointer(self);
DEOPT_IF(dict != NULL, LOAD_METHOD);
DEOPT_IF(((PyHeapTypeObject *)self_cls)->ht_cached_keys->dk_version != cache1->dk_version_or_hint, LOAD_METHOD);
DEOPT_IF(((PyHeapTypeObject *)self_cls)->ht_cached_keys->dk_version != cache1->dk_version, LOAD_METHOD);
STAT_INC(LOAD_METHOD, hit);
PyObject *res = cache2->obj;
assert(res != NULL);

36
Python/specialize.c
View file

@ -57,14 +57,14 @@ static uint8_t adaptive_opcodes[256] = {
/* The number of cache entries required for a "family" of instructions. */
static uint8_t cache_requirements[256] = {
[LOAD_ATTR] = 2, /* _PyAdaptiveEntry and _PyAttrCache */
[LOAD_ATTR] = 1, // _PyAdaptiveEntry
[LOAD_GLOBAL] = 2, /* _PyAdaptiveEntry and _PyLoadGlobalCache */
[LOAD_METHOD] = 3, /* _PyAdaptiveEntry, _PyAttrCache and _PyObjectCache */
[BINARY_SUBSCR] = 2, /* _PyAdaptiveEntry, _PyObjectCache */
[STORE_SUBSCR] = 0,
[CALL] = 2, /* _PyAdaptiveEntry and _PyObjectCache/_PyCallCache */
[PRECALL] = 2, /* _PyAdaptiveEntry and _PyObjectCache/_PyCallCache */
[STORE_ATTR] = 2, /* _PyAdaptiveEntry and _PyAttrCache */
[STORE_ATTR] = 1, // _PyAdaptiveEntry
[BINARY_OP] = 1, // _PyAdaptiveEntry
[COMPARE_OP] = 1, /* _PyAdaptiveEntry */
[UNPACK_SEQUENCE] = 1, // _PyAdaptiveEntry
@ -638,7 +638,7 @@ initial_counter_value(void) {
static int
specialize_module_load_attr(
PyObject *owner, _Py_CODEUNIT *instr, PyObject *name,
_PyAdaptiveEntry *cache0, _PyAttrCache *cache1, int opcode,
_PyAdaptiveEntry *cache0, int opcode,
int opcode_module)
{
PyModuleObject *m = (PyModuleObject *)owner;
@ -671,7 +671,7 @@ specialize_module_load_attr(
SPECIALIZATION_FAIL(opcode, SPEC_FAIL_OUT_OF_VERSIONS);
return -1;
}
cache1->dk_version_or_hint = keys_version;
cache0->version = keys_version;
cache0->index = (uint16_t)index;
*instr = _Py_MAKECODEUNIT(opcode_module, _Py_OPARG(*instr));
return 0;
@ -760,7 +760,7 @@ static int
specialize_dict_access(
PyObject *owner, _Py_CODEUNIT *instr, PyTypeObject *type,
DescriptorClassification kind, PyObject *name,
_PyAdaptiveEntry *cache0, _PyAttrCache *cache1,
_PyAdaptiveEntry *cache0,
int base_op, int values_op, int hint_op)
{
assert(kind == NON_OVERRIDING || kind == NON_DESCRIPTOR || kind == ABSENT ||
@ -782,7 +782,7 @@ specialize_dict_access(
SPECIALIZATION_FAIL(base_op, SPEC_FAIL_OUT_OF_RANGE);
return 0;
}
cache1->tp_version = type->tp_version_tag;
cache0->version = type->tp_version_tag;
cache0->index = (uint16_t)index;
*instr = _Py_MAKECODEUNIT(values_op, _Py_OPARG(*instr));
}
@ -795,12 +795,12 @@ specialize_dict_access(
PyObject *value = NULL;
Py_ssize_t hint =
_PyDict_GetItemHint(dict, name, -1, &value);
if (hint != (uint32_t)hint) {
if (hint != (uint16_t)hint) {
SPECIALIZATION_FAIL(base_op, SPEC_FAIL_OUT_OF_RANGE);
return 0;
}
cache1->dk_version_or_hint = (uint32_t)hint;
cache1->tp_version = type->tp_version_tag;
cache0->index = (uint16_t)hint;
cache0->version = type->tp_version_tag;
*instr = _Py_MAKECODEUNIT(hint_op, _Py_OPARG(*instr));
}
return 1;
@ -810,9 +810,8 @@ int
_Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache)
{
_PyAdaptiveEntry *cache0 = &cache->adaptive;
_PyAttrCache *cache1 = &cache[-1].attr;
if (PyModule_CheckExact(owner)) {
int err = specialize_module_load_attr(owner, instr, name, cache0, cache1,
int err = specialize_module_load_attr(owner, instr, name, cache0,
LOAD_ATTR, LOAD_ATTR_MODULE);
if (err) {
goto fail;
@ -853,7 +852,7 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, Sp
assert(dmem->type == T_OBJECT_EX);
assert(offset > 0);
cache0->index = (uint16_t)offset;
cache1->tp_version = type->tp_version_tag;
cache0->version = type->tp_version_tag;
*instr = _Py_MAKECODEUNIT(LOAD_ATTR_SLOT, _Py_OPARG(*instr));
goto success;
}
@ -862,7 +861,7 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, Sp
Py_ssize_t offset = offsetof(PyObject, ob_type);
assert(offset == (uint16_t)offset);
cache0->index = (uint16_t)offset;
cache1->tp_version = type->tp_version_tag;
cache0->version = type->tp_version_tag;
*instr = _Py_MAKECODEUNIT(LOAD_ATTR_SLOT, _Py_OPARG(*instr));
goto success;
}
@ -883,7 +882,7 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, Sp
break;
}
int err = specialize_dict_access(
owner, instr, type, kind, name, cache0, cache1,
owner, instr, type, kind, name, cache0,
LOAD_ATTR, LOAD_ATTR_INSTANCE_VALUE, LOAD_ATTR_WITH_HINT
);
if (err < 0) {
@ -908,7 +907,6 @@ int
_Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, SpecializedCacheEntry *cache)
{
_PyAdaptiveEntry *cache0 = &cache->adaptive;
_PyAttrCache *cache1 = &cache[-1].attr;
PyTypeObject *type = Py_TYPE(owner);
if (PyModule_CheckExact(owner)) {
SPECIALIZATION_FAIL(STORE_ATTR, SPEC_FAIL_OVERRIDDEN);
@ -942,7 +940,7 @@ _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, S
assert(dmem->type == T_OBJECT_EX);
assert(offset > 0);
cache0->index = (uint16_t)offset;
cache1->tp_version = type->tp_version_tag;
cache0->version = type->tp_version_tag;
*instr = _Py_MAKECODEUNIT(STORE_ATTR_SLOT, _Py_OPARG(*instr));
goto success;
}
@ -965,7 +963,7 @@ _Py_Specialize_StoreAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, S
}
int err = specialize_dict_access(
owner, instr, type, kind, name, cache0, cache1,
owner, instr, type, kind, name, cache0,
STORE_ATTR, STORE_ATTR_INSTANCE_VALUE, STORE_ATTR_WITH_HINT
);
if (err < 0) {
@ -1066,7 +1064,7 @@ _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name,
PyTypeObject *owner_cls = Py_TYPE(owner);
if (PyModule_CheckExact(owner)) {
int err = specialize_module_load_attr(owner, instr, name, cache0, cache1,
int err = specialize_module_load_attr(owner, instr, name, cache0,
LOAD_METHOD, LOAD_METHOD_MODULE);
if (err) {
goto fail;
@ -1111,7 +1109,7 @@ _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name,
SPECIALIZATION_FAIL(LOAD_METHOD, SPEC_FAIL_OUT_OF_VERSIONS);
goto fail;
}
cache1->dk_version_or_hint = keys_version;
cache1->dk_version = keys_version;
*instr = _Py_MAKECODEUNIT(LOAD_METHOD_CACHED, _Py_OPARG(*instr));
}
else {