66 lines
1.9 KiB
Python
66 lines
1.9 KiB
Python
"""Give glibc's free heap pages back to the OS after a long image job (#523).
|
|
|
|
Image work (decode, resize, encode) leaves image-sized free blocks in the
|
|
malloc arenas of the threads that did it; glibc keeps those pages resident.
|
|
``release_free_memory`` calls ``malloc_trim(0)`` once, which returns the free
|
|
pages of every arena and changes no allocator setting (no ``mallopt``, no
|
|
``MALLOC_ARENA_MAX``: ComfyUI owns this process's allocator).
|
|
|
|
glibc only: on Windows, macOS and musl (Alpine) it does nothing. It never
|
|
raises; a missing or failing ``malloc_trim`` is a quiet ``False``.
|
|
"""
|
|
|
|
import ctypes
|
|
import os
|
|
import sys
|
|
import threading
|
|
|
|
_lock = threading.Lock()
|
|
# Not looked up yet; after the lookup, the function or None.
|
|
_NOT_LOOKED_UP = object()
|
|
_trim = _NOT_LOOKED_UP
|
|
|
|
|
|
def _glibc() -> bool:
|
|
"""Whether this process runs on glibc (musl has no CS_GNU_LIBC_VERSION)."""
|
|
if not sys.platform.startswith("linux"):
|
|
return False
|
|
try:
|
|
version = os.confstr("CS_GNU_LIBC_VERSION")
|
|
except (AttributeError, ValueError, OSError):
|
|
return False
|
|
return bool(version) and version.startswith("glibc")
|
|
|
|
|
|
def _malloc_trim():
|
|
"""glibc's ``malloc_trim``, looked up once; None where there is none."""
|
|
global _trim
|
|
with _lock:
|
|
if _trim is _NOT_LOOKED_UP:
|
|
_trim = _lookup()
|
|
return _trim
|
|
|
|
|
|
def _lookup():
|
|
if not _glibc():
|
|
return None
|
|
try:
|
|
trim = ctypes.CDLL(None).malloc_trim
|
|
except (OSError, AttributeError):
|
|
return None
|
|
trim.argtypes = [ctypes.c_size_t]
|
|
trim.restype = ctypes.c_int
|
|
return trim
|
|
|
|
|
|
def release_free_memory() -> bool:
|
|
"""Return free heap pages to the OS once (glibc); True when it ran."""
|
|
trim = _malloc_trim()
|
|
if trim is None:
|
|
return False
|
|
try:
|
|
trim(0)
|
|
except Exception: # a foreign libc symbol: never fail the caller's job
|
|
return False
|
|
return True
|