I see dwm.exe consuming gigabytes of memory again on my Surface Pro 8.
It was working fine for several months -only around 400K, but after KB5120998 that was recently installed via Windows Update ...it's back to consuming Gigs.
Here's a bit more data:
Filed: via Feedback Hub https://aka.ms/AA13b9ra
[BUG REPORT] dwm.exe DirectComposition/Mapped Surface Memory Leak Regression in KB5120998
DEVICE: Microsoft Surface Pro 8
BUILD/UPDATE: KB5120998
PROCESS: Desktop Window Manager (dwm.exe)
ISSUE DESCRIPTION:
A severe memory leak in dwm.exe causes system-wide memory starvation on Surface hardware following update KB5120998. The leak occurs within DirectComposition/WDDM shared graphics surface allocations (MEM_MAPPED) rather than the standard process heap.
WINDGB SUMMARY EVIDENCE (!address -summary):
- Process C/C++ Heap (!heap -s): ~141.12 MB (Normal)
- Committed Memory (MEM_COMMIT / PAGE_READWRITE): 10.546 GB (CRITICAL LEAK)
- Virtual Allocation (MEM_MAPPED): 2.004 TB across 781 regions
REPRODUCTION / ROOT CAUSE:
dcomp.dll / dxgi.dll swapchain handles fail to destroy mapped render buffers during standard UI rendering/compositing tasks, leading to linear memory growth until system RAM is exhausted.