So I've been noticing extremely high memory usage lately. With just Chrome with 20 tabs open, I get 13.5 / 16GB of my memory being used. Task manager reports that Chrome only uses about 3GB of memory. All of the remaining processes reported in Task Manager combined make less than 1GB of additional memory as most of them use between 10MB and 50MB.

I've used RamMap to get more details and I found that the Nonpaged Pool is extremely high at 5.7GB. Here's an image of RamMap.

I've used poolmon and discovered that two things are using up an enourmous amount of the nonpaged pool. Here's an image of poolmon.

According to a Google tag search and this list here, this is what those 2 tags are for:

  • FMic - fltmgr.sys - IRP_CTRL structure
  • Irp - unknown - Io, IRP packets

But now I've hit a dead end. I've seen other similar questions, but none that deal with these tags. Other people's problem usually comes from a driver and they can just update it. But in this case, I don't know how to fix that.

I've found the file fltMgr.sys in C:\Windows\System32\drivers, but it seems it's a Microsoft thing. Under Properties -> Details, its name is "Microsoft Windows Operating System" and its file description is "Microsoft Filesystem Filter Manager". i.e. this isn't just a driver I can update.

As for the Irp tag, I have no clue.

Any suggestions? Where do I take it from here and what can I do?

EDIT 03/03/18: I do not own Killer NIC.

I've used xperf to record and I've got this far. Not really sure where to go from here, alternatively I could upload the .etl file, though it's quite large so not sure where. Let me know if uploading it will be of help.

It's maybe 40 minutes after reboot and already have 517MB Nonpaged pool.

EDIT 04/03/18 #1: Nonpaged pool currently at 1GB after a day. It seems it increases at a rate of ~1GB per day. Output of fltmc can be found here.

As for Irp - I do not use antivirus or backup programs, unless you count Windows Defender. I do, however, use a symlink from my C: drive (SSD) to my F: drive (HDD) for Google Chrome and Skype's cache folders as they were causing writes of 20GB per day on disk, which I didn't want on my SSD. This cache is working fine and being written to my HDD just fine though, I don't think it would cause failed I/O.

I do also have a Raid 0 array of 2 HDDs (1 TB each) created via Windows's built-in Storage Spaces, not via the BIOS or anything like that. I don't suppose this could have anything to do with the Irp thing either?

Finally, I also record my gameplay when I play video games. It's automatically running in the background as soon as I launch a game, using a client called Plays.TV. But again, this is successful and I don't see why the I/O request would be issued but not completed. The videos finish recording as soon as I exit a game.

EDIT 04/03/18 #2: I've used typeperf "Memory\Pool Nonpaged Bytes" -si 20 -o npptracker.csv and then graphed the results as suggested by @HelpingHand. I have also annotated the graph with all events, so you can see what action corresponds to the Nonpaged Bytes jumping up or down. Here is the graph. On it, you might see a few things you don't recognise:

  • PUBG - Short for PlayerUnknown's BattleGrounds, it is a video game I've been playing recently
  • Plays.TV - video recording client which automatically starts recording as soon as I enter a game and stops recording when I quit it. It also records metadata for some games and places it on the timeline of the video as a marker, e.g. I will see markers in the timeline at times when I've killed someone. This metadata is recorded in a .framelets file.
  • Twitch.tv - a website for streaming
  • Bot for a browser game - just a bot which does HTML requests. It only runs for about 30 to 60 minutes at a time and I'm fairly confident it has no effect.

As you can see on the graph, I've used Xperf using the following command for about 7 minutes: Xperf -on PROC_THREAD+LOADER+POOL -stackwalk PoolAlloc+PoolFree+PoolAllocSession+PoolFreeSession -BufferSize 1024 -MinBuffers 256 -MaxBuffers 256 -MaxFile 1024 -FileMode Circular

This has produced a 1GB .etl file which I have zipped and uploaded here (80MB).

Finally, I've used poolmon again about 2-3 minutes after I stopped xperf. I forgot to put it on the timeline graph. Here is an image of the result.

  • Have you got a Killer network card? – David Marshall Mar 3 '18 at 15:54
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    I would suggest install Windows Performance Toolkit in order to obtain xperf and WPA. I would reboot the computer, pool memory should be low. Run Xperf -on PROC_THREAD+LOADER+POOL -stackwalk PoolAlloc+PoolFree+PoolAllocSession+PoolFreeSession -BufferSize 1024 -MinBuffers 256 -MaxBuffers 256 -MaxFile 256 -FileMode Circular to start a trace. After pool mem has increased run: xperf -stop -d pool.etl to create a trace. Load the pool.etl in WPA. Filer for AIFO (mem allocated inside freed outside). Feel free to link the etl. – HelpingHand Mar 3 '18 at 15:55
  • Thanks for the comments. Check out the 2 edits. @HelpingHand I can try to upload the .etl file somewhere, if you need me to, though it seems it might have personal information, at least that's the warning I got when I made the trace. – Sam Mar 3 '18 at 17:25
  • I wonder if the capture spanned the leak happening or at least at a rate to be obvious? Here is an example trace captured in the same way using the Microsoft/Sysinternals - NotMyFault test app as an example of a driver that can leak non-paged pool - imgur.com/a/1U8UR . Note the impacting size and the stack columns. ... – HelpingHand Mar 3 '18 at 23:46
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    Irp refers to I/O request packets. There will be one of these for every I/O request that has been issued, but not yet completed. The poolmon display shows that there are about 5.2 million of them, which is an enormous number. fltmgr.sys is the manager and framework for file system minifilter drivers - if problem analysis points to fltmgr.sys the problem is almost always in a minifilter. minifilters are normally associated with antivirus products, backup programs, and the like. As a test, disable or remove all third-party stuff of that nature and see if the problem goes away. – Jamie Hanrahan Mar 4 '18 at 10:31

Analyzing the trace in WPA.exe shows that the FMic pool usage comes from RazerCortex.exe which occurs while creating files (KernelBase.dll!CreateFileW).

enter image description here

This also causes the IRP (which stands for I/O request packet) usage:

enter image description here

The rzudd.sys driver also causes IRP usage:

enter image description here

So update the Razor tool or better remove it (and every other Razor related software/driver).

  • Thanks for helping with the analysis. Are you certain about this though? I am not really sure what's going on in the images, but the counts and sizes seem smaller than they do for Chrome and overall somewhat small in general. Could this really be the cause? I will uninstall Razer Cortex now and monitor for a day or two to see what happens. I'll also make a new graph again with the helf of typeperf and compare it to the previous one. I'll post update in a few days. – Sam Mar 5 '18 at 16:25
  • I can only tell you want I see in the trace. It doesn't show what happened before (so largest part is UNKNOWN for process with no stack (n/a)) – magicandre1981 Mar 5 '18 at 16:30
  • the rzudd.sys also causes IRP usage, so really remove everything Razor related from the system. – magicandre1981 Mar 5 '18 at 19:54
  • Agreed - remove everything Razer from your machine, keyboard and mice included. – Jamie Hanrahan Mar 6 '18 at 11:31
  • Yeah, I'm definitely not about to remove my keyboard because of a memory leak... – Sam Mar 6 '18 at 18:46

I had the same exact problem. FMic and IRP tags were consistently at the top, taking up gigs of non-paged pool if my computer was left on for long periods without a proper reboot. I pinpointed it to Razer Cortex, my only Razer software at the time, and the second I uninstalled it my non-paged pool shrunk down to 1.2GB instead of 3-4GB, after having my computer on for a few days. Previously I had tried reinstalling the Killer Network drivers and removed a Razer driver for a device I was no longer using, but neither helped as much as removing Cortex.

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    This doesn’t help the author, it’s great information, maybe even a great answer to your question though – Ramhound Mar 8 '18 at 1:43
  • This was the cause of my memory leak. Thanks – Lews Therin Nov 13 '20 at 6:38

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