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Memory leak in HR20-700

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by mkinkade, Jun 5, 2008.

  1. Jun 5, 2008 #1 of 36
    mkinkade

    mkinkade Cool Member

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    Has anyone else noticed that there seems to be a memory leak in the current software? Twice now I've noticed stutter when playing back content. A reboot has cleared up the problem each time. So it looks like there may be a memory leak that a reboot will clear up or a while.

    Anyone know if this will be fixed in the next release?

    Thanks,
    --Mark
     
  2. Jun 5, 2008 #2 of 36
    MartyS

    MartyS New Member

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    There have been a number of issues over the last year with audio stutters and drops. The current CE (cutting edge) candidate has solved that for me. \

    However, before you re-boot each time, oftentimes all you need to do is stop the recording and restart it. Sometimes that works. Other times, if you skip back 6 seconds, you'll hear the audio.

    What version of the software do you have? How are you connected for audio? Is it direct to the tv via component or HDMI, are you going through a received via optical?

    Sometimes a bad cable can make that happen as well.
     
  3. Jun 5, 2008 #3 of 36
    bmerrow

    bmerrow Legend

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    Audio stutter has occurred for HR20 and HR21 for last several NRs - it may have improved in latest NR rolling out but it is too early to be certain. The problem is sporadic and sometimes a quick skip or two will fix it and sometimes a reboot is needed. My experience is that a periodic menu reset (reboot) is a good idea - it corrects clock drift, audio stutter improves, and general slowdown of HR2x is improved for a day or three.
     
  4. Jun 6, 2008 #4 of 36
    TomCat

    TomCat Broadcast Engineer

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    I'm puzzled by why you might think it is due to a memory leak simply because a reboot fixes it.

    A memory leak is usually a problem with RAM partitioned for a running application on a PC expanding into another application's "protected" memory space, because they are designed in a way that does not keep them from conflicting with each other regarding how and where things are written to RAM. Either that or improper cleaning up (register flush routines) that allow the RAM size for an application to grow beyond its allocation size. In either case, that can cause a freeze or platform crash, but it doesn't affect HDD performance.

    There is only one "application" running on a DVR platform, which is the OS itself. There is nothing for it to conflict with in RAM. It may be multi-threaded, but the OS is designed as a coherent system, not as conflicting applications. It would be poorly-written indeed if it grew beyond its allocation, but again, that would cause a freeze or a reboot, not sluggish playback performance.

    There may be a number of issues that a reboot fixes, including sluggish performance, but that hardly implies a memory leak. About the only things they have in common is that a reboot (on a PC at least) will fix that as well
     
  5. Jun 7, 2008 #5 of 36
    jeffshoaf

    jeffshoaf Icon

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    While the issues you describe are memory-related, they're not normally considered to be memory leaks - a memory leak is when an application or process allocates memory and then doesn't deallocate some or all of that memory when it's through with it. You're describing general protection faults (GPFs).

    If a process with a memory leak is called over and over again, the RAM available to all processes will decrease each time until there's not enough available memory to start another process. If the OS uses disk as virtual memory, the system will continue to run but will slow down dramatically as it swaps processes between RAM and disk. A reset does temporarily correct this issue since it releases all of the unreleased memory tied up by the memory leaks.

    Here's a reference: http://en.wikipedia.org/wiki/Memory_leak
     
  6. Jun 7, 2008 #6 of 36
    mkinkade

    mkinkade Cool Member

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    Dec 8, 2006
    It's not just playback while another show is recording that slows down on me. Its everything in the interface. The guide doesn't scroll smoothly, the menus take longer to come up, etc. And all this happens while there isn't anything recording on either tuner. I'm assuming that the OS for the dvr is a modern one and uses virtual memory. If one of the processes has a memory leak then other processes will need to have their memory swapped to and from the VM store more often which can cause all the slowness/stuttering that I'm seeing. It also explains why rebooting the system clears up the problem.
     
  7. Jun 7, 2008 #7 of 36
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    The OS is Linux and I doubt it even uses the disk for virtual memory.
     
  8. Jun 7, 2008 #8 of 36
    P Smith

    P Smith Mr. FixAnything

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    Really ? But have you look into a content of the HR2x SWAP partiton ?
     
  9. Jun 7, 2008 #9 of 36
    K4SMX

    K4SMX Hall Of Fame

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    There are a number of products available to fix memory leaks, e.g., Coenzyme Q-10 and Phosphatidylserine. I take quite a few myself.....:)
     
  10. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Well, perhaps you might share some of your knowledge with us.
     
  11. P Smith

    P Smith Mr. FixAnything

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    I did, now your turn to stand corrected and do that 'dirty' job researching HDD SWAP content, I have enough other interests.
     
  12. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I see you're being your usual "help". [somethings never change]
     
  13. jeffshoaf

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    If we assume that the disk is not used for virtual memory and that the OP's issues are caused by memory leaks, then the OS would probably crash or lock up when it's RAM is all allocated instead of just stuttering.

    I'm not prepared to make either of those assumptions...
     
  14. P Smith

    P Smith Mr. FixAnything

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    I see you still on same course - never accept own mistakes, never do except do talk here;
    I would make the test procedure for you pretty simple:
    - connect external disk; preferable cleaned - at least 00ed SWAP partition
    - play with DVR while it become sluggish
    - disconnect power cord
    - bring the disk to PC, if it running Windows use WinHex or similar program
    - dig into content of SWAP partition
    - tell us how it filled.
     
  15. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    And then you could JUST tell us [share] what you've found by doing something like this.
    Why would I want to break into a perfectly good working DVR?
     
  16. jwd45244

    jwd45244 Hall Of Fame

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    And this would tell you exactly what relative to a supposed memory leak? Linux SWAP partitions are different that Windows ones. Yes, linux can use them but its use of them differs from Windows page files.

    Is there any reason to be snide toward people here?
     
  17. P Smith

    P Smith Mr. FixAnything

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    There wasn't snide toward, there wasn't a reason for that; there was mistake with a declaration in post#7. And still there.
     
  18. GregLee

    GregLee Hall Of Fame

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    I agree that post #7 is mistaken. If the HR2x operating system is Linux, that certainly gives no grounds for thinking it does not use virtual memory.
     
  19. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "Doubting" is not a mistake [and as such, there is no need for a correction]. :)
     
  20. P Smith

    P Smith Mr. FixAnything

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    Oh man !
     

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