FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-117657: Fix small issues with instrumentation and TSAN by DinoV · Pull Request #118064 · python/cpython · GitHub

/ cpython Public

gh-117657: Fix small issues with instrumentation and TSAN #118064

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
DinoV merged 1 commit into from
Apr 30, 2024
Conversation 4 Commits 1 Checks 0 Files changed
Merged

gh-117657: Fix small issues with instrumentation and TSAN #118064

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension .c  (4) .h  (3) All 2 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
11 changes: 9 additions & 2 deletions Include/internal/pycore_pyatomic_ft_wrappers.h
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,10 @@ extern "C" {
_Py_atomic_load_uint8(&value)
#define FT_ATOMIC_STORE_UINT8(value, new_value) \
_Py_atomic_store_uint8(&value, new_value)
#define FT_ATOMIC_LOAD_UINT8_RELAXED(value) \
_Py_atomic_load_uint8_relaxed(&value)
#define FT_ATOMIC_LOAD_UINT16_RELAXED(value) \
_Py_atomic_load_uint16_relaxed(&value)
#define FT_ATOMIC_STORE_PTR_RELAXED(value, new_value) \
_Py_atomic_store_ptr_relaxed(&value, new_value)
#define FT_ATOMIC_STORE_PTR_RELEASE(value, new_value) \
Expand All @@ -49,7 +53,8 @@ extern "C" {
_Py_atomic_store_ssize_relaxed(&value, new_value)
#define FT_ATOMIC_STORE_UINT8_RELAXED(value, new_value) \
_Py_atomic_store_uint8_relaxed(&value, new_value)

#define FT_ATOMIC_STORE_UINT16_RELAXED(value, new_value) \
_Py_atomic_store_uint16_relaxed(&value, new_value)
#else
#define FT_ATOMIC_LOAD_PTR(value) value
#define FT_ATOMIC_STORE_PTR(value, new_value) value = new_value
Expand All @@ -62,12 +67,14 @@ extern "C" {
#define FT_ATOMIC_LOAD_PTR_RELAXED(value) value
#define FT_ATOMIC_LOAD_UINT8(value) value
#define FT_ATOMIC_STORE_UINT8(value, new_value) value = new_value
#define FT_ATOMIC_LOAD_UINT8_RELAXED(value) value
#define FT_ATOMIC_LOAD_UINT16_RELAXED(value) value
#define FT_ATOMIC_STORE_PTR_RELAXED(value, new_value) value = new_value
#define FT_ATOMIC_STORE_PTR_RELEASE(value, new_value) value = new_value
#define FT_ATOMIC_STORE_UINTPTR_RELEASE(value, new_value) value = new_value
#define FT_ATOMIC_STORE_SSIZE_RELAXED(value, new_value) value = new_value
#define FT_ATOMIC_STORE_UINT8_RELAXED(value, new_value) value = new_value

#define FT_ATOMIC_STORE_UINT16_RELAXED(value, new_value) value = new_value
#endif

#ifdef __cplusplus
Expand Down
8 changes: 5 additions & 3 deletions Objects/genobject.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
#include "pycore_modsupport.h" // _PyArg_CheckPositional()
#include "pycore_object.h" // _PyObject_GC_UNTRACK()
#include "pycore_opcode_utils.h" // RESUME_AFTER_YIELD_FROM
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_*
#include "pycore_pyerrors.h" // _PyErr_ClearExcState()
#include "pycore_pystate.h" // _PyThreadState_GET()

Expand Down Expand Up @@ -329,10 +330,11 @@ gen_close_iter(PyObject *yf)
static inline bool
is_resume(_Py_CODEUNIT *instr)
{
uint8_t code = FT_ATOMIC_LOAD_UINT8_RELAXED(instr->op.code);
return (
instr->op.code == RESUME ||
instr->op.code == RESUME_CHECK ||
instr->op.code == INSTRUMENTED_RESUME
code == RESUME ||
code == RESUME_CHECK ||
code == INSTRUMENTED_RESUME
);
}

Expand Down
4 changes: 2 additions & 2 deletions Python/bytecodes.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,7 @@
#include "pycore_object.h" // _PyObject_GC_TRACK()
#include "pycore_opcode_metadata.h" // uop names
#include "pycore_opcode_utils.h" // MAKE_FUNCTION_*
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_LOAD_PTR_ACQUIRE
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_*
#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
#include "pycore_pystate.h" // _PyInterpreterState_GET()
#include "pycore_range.h" // _PyRangeIterObject
Expand Down Expand Up @@ -163,7 +163,7 @@ dummy_func(
if ((oparg & RESUME_OPARG_LOCATION_MASK) < RESUME_AFTER_YIELD_FROM) {
CHECK_EVAL_BREAKER();
}
this_instr->op.code = RESUME_CHECK;
FT_ATOMIC_STORE_UINT8_RELAXED(this_instr->op.code, RESUME_CHECK);
}
}

Expand Down
2 changes: 1 addition & 1 deletion Python/ceval.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,7 @@
#include "pycore_opcode_metadata.h" // EXTRA_CASES
#include "pycore_optimizer.h" // _PyUOpExecutor_Type
#include "pycore_opcode_utils.h" // MAKE_FUNCTION_*
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_LOAD_PTR_ACQUIRE
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_*
#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
#include "pycore_pystate.h" // _PyInterpreterState_GET()
#include "pycore_range.h" // _PyRangeIterObject
Expand Down
2 changes: 1 addition & 1 deletion Python/ceval_macros.h
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,7 @@ GETITEM(PyObject *v, Py_ssize_t i) {
/* The integer overflow is checked by an assertion below. */
#define INSTR_OFFSET() ((int)(next_instr - _PyCode_CODE(_PyFrame_GetCode(frame))))
#define NEXTOPARG() do { \
_Py_CODEUNIT word = *next_instr; \
_Py_CODEUNIT word = {.cache = FT_ATOMIC_LOAD_UINT16_RELAXED(*(uint16_t*)next_instr)}; \
opcode = word.op.code; \
oparg = word.op.arg; \
} while (0)
Expand Down
2 changes: 1 addition & 1 deletion Python/generated_cases.c.h
Show comments
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

9 changes: 6 additions & 3 deletions Python/instrumentation.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -625,9 +625,10 @@ de_instrument(PyCodeObject *code, int i, int event)
return;
}
CHECK(_PyOpcode_Deopt[deinstrumented] == deinstrumented);
*opcode_ptr = deinstrumented;
FT_ATOMIC_STORE_UINT8_RELAXED(*opcode_ptr, deinstrumented);

mpage Apr 19, 2024 •
edited
Loading

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Is relaxed strong enough? Do any consumers need to see the updates that are sequenced-before this store? Same comment applies to the below instances of using relaxed stores to update bytecode.

DinoV Apr 19, 2024

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

In the deinstrumented case if we race and still see the instrumented opcode the data will still be there. In the instrumented case I think we do need some more synchronization around the tooling metadata, if we see the instrumented opcode before seeing the writes to the data that'll be bad.

I had originally had synchronizeds reads/writes around that in d8ea6bb#diff-adaefb7da847260ef7aff6e66007bc83f5b226c5389a23e1c9ea622c3b02c419 but the thought was that the synchronization around _PyFrame_GetCode(frame)->_co_instrumentation_version would be sufficient (which is in the latest version of #116775).

But that doesn't actually seem to be good enough - there's still some rare TSAN failures around the instrumentation data. But my plan is to push the synchronization there instead of on the opcode because I don't think we want to do acquire loads on the byte code which would be required to make a release write here meaningful.
if (_PyOpcode_Caches[deinstrumented]) {
instr[1].counter = adaptive_counter_warmup();
FT_ATOMIC_STORE_UINT16_RELAXED(instr[1].counter.as_counter,
adaptive_counter_warmup().as_counter);
}
}

Expand Down Expand Up @@ -702,8 +703,10 @@ instrument(PyCodeObject *code, int i)
int deopt = _PyOpcode_Deopt[opcode];
int instrumented = INSTRUMENTED_OPCODES[deopt];
assert(instrumented);
*opcode_ptr = instrumented;
FT_ATOMIC_STORE_UINT8_RELAXED(*opcode_ptr, instrumented);
if (_PyOpcode_Caches[deopt]) {
FT_ATOMIC_STORE_UINT16_RELAXED(instr[1].counter.as_counter,
adaptive_counter_warmup().as_counter);
instr[1].counter = adaptive_counter_warmup();
}
}
Expand Down
Back | FazBrowse Home | New Git URL