Reduce RAM usage, fix VRAM OOMs, and fix Windows shared memory spilling with adaptive model loading (#11845)

comfy/windows.py

@@ -0,0 +1,52 @@
+import ctypes
+import logging
+import psutil
+from ctypes import wintypes
+
+import comfy_aimdo.control
+
+psapi = ctypes.WinDLL("psapi")
+kernel32 = ctypes.WinDLL("kernel32")
+
+class PERFORMANCE_INFORMATION(ctypes.Structure):
+    _fields_ = [
+        ("cb", wintypes.DWORD),
+        ("CommitTotal", ctypes.c_size_t),
+        ("CommitLimit", ctypes.c_size_t),
+        ("CommitPeak", ctypes.c_size_t),
+        ("PhysicalTotal", ctypes.c_size_t),
+        ("PhysicalAvailable", ctypes.c_size_t),
+        ("SystemCache", ctypes.c_size_t),
+        ("KernelTotal", ctypes.c_size_t),
+        ("KernelPaged", ctypes.c_size_t),
+        ("KernelNonpaged", ctypes.c_size_t),
+        ("PageSize", ctypes.c_size_t),
+        ("HandleCount", wintypes.DWORD),
+        ("ProcessCount", wintypes.DWORD),
+        ("ThreadCount", wintypes.DWORD),
+    ]
+
+def get_free_ram():
+    #Windows is way too conservative and chalks recently used uncommitted model RAM
+    #as "in-use". So, calculate free RAM for the sake of general use as the greater of:
+    #
+    #1: What psutil says
+    #2: Total Memory - (Committed Memory - VRAM in use)
+    #
+    #We have to subtract VRAM in use from the comitted memory as WDDM creates a naked
+    #commit charge for all VRAM used just incase it wants to page it all out. This just
+    #isn't realistic so "overcommit" on our calculations by just subtracting it off.
+
+    pi = PERFORMANCE_INFORMATION()
+    pi.cb = ctypes.sizeof(pi)
+
+    if not psapi.GetPerformanceInfo(ctypes.byref(pi), pi.cb):
+        logging.warning("WARNING: Failed to query windows performance info. RAM usage may be sub optimal")
+        return psutil.virtual_memory().available
+
+    committed = pi.CommitTotal * pi.PageSize
+    total = pi.PhysicalTotal * pi.PageSize
+
+    return max(psutil.virtual_memory().available,
+               total - (committed - comfy_aimdo.control.get_total_vram_usage()))
+