In regards to http://www.osronline.com/showthread.cfm?link=268386
“It will be OK. KeEnter/LeaveCriticalRegion calls are extremely cheap and prevent the APCs from coming. You should use these calls as well.”
Do you mean use those around the ExAcquireFastMutexUnsafe or from before that until just after the ExReleaseFastMutexUnsafe ?
Thanks.