Defrag Tools: #6 - RAMMap

Play Defrag Tools: #6 - RAMMap

The Discussion

  • User profile image
    schroedl

    Excellent. Looking forward to the VMMap video.

  • User profile image
    samhmaria

    Another great show. Can't wait for the next one. Thanks again.

  • User profile image
    Phililp Saunders

    the memory map you showned in the video (memory transitition.png) where can we download it?

  • User profile image
    windev

    @Phililp Saunders: It's from the Windows Internals books/David Solomon kernel course.  It is copyrighted to them, so I can't make it available for download Sad

  • User profile image
    siodmy

    repurposed is bad...

    http://imageshack.us/photo/my-images/854/repurposedisbad.png/

    new laptop, but it's maybe because I didn't turn it off since a few days ago. Maybe. I hope.

  • User profile image
    windev

    @siodmy: The repurposed of 0-4 is expected. It is the 5-7 that matter. You are getting enough memory pressure on 5 (1.6Gb -- x8 reused) to raise interest at least. Adding a few gigs will definitely help in those times - its not critical though.

  • User profile image
    James G

    Andrew, Please update your Flash player! you should be up to 11.4.402.265
    you are still using the old 11.3.300.271 which is exploitable. Great Show, I hope you continue to make new shows every week, I look forward to them.

  • User profile image
    windev

    @James G: I use a vhd for the show and it only runs during taping (so I don't add features to the install without you seeing it). The next time I prepare for a show, I'll make sure to give it some time to do the updates. Can't set a bad example can I!

    The show will be weekly for at least another ~10 weeks based on the current episode recording schedule. We tape a few at a time if it is the same topic.

    Next is vmmap, then we have a special edition, then inbox tools. After that in a yet to be decided order is 3+ on Windows Performance Toolkit, 2+ on Procdump, 4+ on Debugging Tools for Windows, Network Monitor, Fiddler and PsTools. In the maybe bucket is audio, video, printing and device troubleshooting (1 each). We will also probably do a live show on Channel 9 Live at Build.

    Lots and lots of shows to watch!  If your favorite tool isn't in that list, drop us an email at defragtools@microsoft.com or write a comment and we'll add it to the list or move it forward.

  • User profile image
    ggjjhkjhhg

    fegnddmn

  • User profile image
    Adelino​Araujo

    I have a question: you talked about Hyper-V and a vm starts and says to the memory manager hey get me a big part of your ram, and it needs to be continuous. This may work for a fixed memory vm, but what about dynamic memory?

    The startup memory block can be 1gb and later need a little bit more, and perhaps find that memory has been occupied by other vm's...

    Thanks

    Adelino

  • User profile image
    jeh

    9:40 - 5 GB of RAM in the zero list "which I've never touched since the PC was booted. That RAM is completely wasted." What makes you think it's never been touched? It's not as if RAM, once used, never gets put back on the zero list! It is - as shown by the diagram at 9:51. 

    btw, it's amusing how closely the diagram at 9:51 resembles the one in VAX/VMS Internals and Data Structures. ;) 

  • User profile image
    Hugo Andrade


    There is the possibility of running RAMMAPP via command line. For example create a script for execution and automatic cleaning

  • User profile image
    Bhavin

    Is there a way we can get Priority 4-7 memory and amount being repurposed via a command line?

    What is the best way to detect memory leaks and badly written applications causing issues on a device?

  • User profile image
    Deborah

    Excellent instructions and information sharing! RAMMAP continues to be relevant today 4/28/2021.

  • User profile image
    GGrimm
    Thanks a lot for your excellent program!
    Do you have any idea what might be wrong if a lot of memory (several GB) is kept in the "Transition" state?
  • User profile image
    Tat Sean

    Our production server shows the similar "issue" as mentioned by GGrimm which is the "Transition" column has size which 2x bigger than the "Active" column. What does it indicate?

  • User profile image
    ChadBeeder
    There is some information about transition pages on docs.microsoft.com here: https://docs.microsoft.com/en-us/windows/win32/memory/working-set

    "A soft page fault occurs when... The page is in transition, because it either has been removed from the working sets of all processes that were using the page and has not yet been repurposed, or it is already resident as a result of a memory manager prefetch operation."

    "After a page is removed from the working sets of all processes that were using it, the page becomes a transition page. Transition pages remain cached in RAM until the page is either referenced again by some process or repurposed (for example, filled with zeros and given to another process)."

    So essentially if you have a lot of transition pages, it doesn't indicate a problem; these are pages (typically a file from disk, mapped into RAM) which have either been freed by all processes using them, or have been prefetched in the background to help speed up the process in the event the file is referenced later -- i.e. preloading binaries to help speed up app launches.

    If the system is not under memory pressure, there's not much point in freeing/zeroing these pages. It's better to keep them cached in RAM so that we don't have to take a hard page fault (that is, disk I/O) in the event the file is mapped into memory again.

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