My firefox suddenly become sluggish and then froze. I opened Process Explorer to see what's going on and noticed the main thread of firefox.exe was stuck in the kernal function
NtAllocateVirtualMemory. At that time, the process was only using 1.5GB of virtual memory space and I had more than 1GB of commit limit free and at least 1GB of RAM free. I thought the memory space of Firefox might have become too fragmented, so I killed it.
Then I got a surprise graph like below.
As you can see, there has always been RAM free during the entire period but I seemed to have hit commit limit anyhow. The page files are set to system managed and the system drive have more than 17GB free, so I have no idea how I could hit the limit.... Any thoughts on this?
System is Windows 10 build 10586. I have 8GB of RAM.
(It seems Firefox or some related thing has claimed a hidden 3-4 GB of virtual memory space. I think it could be the display driver, but why did the system not expand the page file?)