Poor performance in guest OS compared to PD 14

Discussion in 'Parallels Desktop 15 for Mac Technical Preview' started by KorkyPlunger, Apr 18, 2019.

  1. KorkyPlunger

    KorkyPlunger Kilo Poster

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    I've been running PD 15 for a couple days now, and the thing that immediately jumps out is that the Guest OS becomes extremely sluggish when doing anything that involves disk I/O.

    This is anecdotal of course, but I/O seems to be the common factor in my case.

    Examples include:
    - compiling under Visual Studio makes the guest OS nearly unresponsive for seconds at a time
    - running a python script that creates lots of files causes similar unresponsiveness
    - resuming the VM after a suspension the night before can take 5-10 minutes before it is usable.

    Did something change in the default I/O handler? I'm not using the new NVME driver, I just switched to PD15 and resumed my PD14 VM.

    I've filed a couple technical reports on this: 307667507 (compiling in visual studio), and 307945062 (resuming VM). I also filed another report for the unresponsiveness when compiling, but was never presented with the report ID so I don't know if it actually completed.
     
  2. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Added another report: 307959146
     
  3. KorkyPlunger

    KorkyPlunger Kilo Poster

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    And another: 307982950
     
  4. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Added another report. This is for another instance of me resuming my VM and the guest OS being unresponsive for a long time (it's been close to 10 minutes now and the guest is still mostly unresponsive). Occasionally (perhaps once every few minutes) a mouse click will register, but mostly it appears hung -- cannot even open the task manager.
    Report ID 308065626

    I'm afraid at this point I need to switch back to PD14 to get work done; I'll check out PD15 again when the next update is released.

    ---------
    UPDATE
    ---------

    The Guest OS finally became responsive again about 15 minutes later. While it was still unresponsive and using up tremendous amounts of CPU, I took a spindump using

    sudo -i
    spindump -file spindump.txt; vm_stat > vm_stat.txt && zprint -t -w -s >> vm_stat.txt

    It's too large to attach here; I'll email it to @Dmitry@Parallels
     
    Last edited: Apr 19, 2019
  5. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Sent another technical data report today, same issue: 308441267

    Please let me know if this is enough, or you would like me to continue sending technical data reports for this issue.
     
  6. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Thank you very much, Chris, for valuable data. We're working on disk improvements for the next Tech Preview round.
     
  7. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Ok, I'll hold off on sending reports for now. If you need more, just let me know.
     
  8. KorkyPlunger

    KorkyPlunger Kilo Poster

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    An update here @Dmitry@Parallels : I was previously reporting these as a problem with the PD15 beta (see https://forum.parallels.com/threads/poor-performance-in-guest-os-compared-to-pd-14.347035/) but I am now seeing this after switching back to PD14 as well. I just realized that this behavior may have been correlated with the upgrade to Mojave 10.14.4. There is a separate thread about this 10.14.4 issue at:

    https://forum.parallels.com/threads/performance-problems-in-windows-10-after-upgrade-to-v14.345305/ where

    where it seems that many people are having the same issue.

    I've gathered more data on this using PD14 and sent technical data under report #311181390

    -- FOLLOWUP --

    After switching to the Apple hypervisor as others have recommended, I have not seen this issue again today, and CPU use seems much better (at least under PD14; haven't tried it yet under PD 15)
     
    Last edited: May 14, 2019
  9. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Hi @KorkyPlunger, we're working on the new beta build that should help to address this issue. You will receive an email notification once the update is available.
     
  10. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Sounds great. In the meantime switching to the Apple hypervisor has completely removed the issue for me. Haven't had any pauses like that in 9 days.
     
  11. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    @KorkyPlunger, see what's new in the second round of Tech Preview program: https://my.parallels.com/desktop/beta#round2
    Let me know how this build runs on your system please with Parallels hypervisor.
     
  12. KorkyPlunger

    KorkyPlunger Kilo Poster

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    @Dmitry@Parallels unfortunately the problem still occurs on the latest PD15 beta when using the Parallels Hypervisor. I have no issues when using the Apple hypervisor.
    I filed another set of technical data under the new beta, in case it's helpful: # 313738006
     
  13. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Thank you very much, @KorkyPlunger, I have raised priority for this issue, we keep investigating.
    For now, are you satisfied with current performance using Apple hypervisor?
     
  14. KorkyPlunger

    KorkyPlunger Kilo Poster

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    @Dmitry@Parallels Yes, it's a little slower than the parallels one used to be, in terms of raw performance, but not much. It's totally acceptable for now.
     
  15. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Hi @KorkyPlunger, can you please send us a tech report with Apple hypervisor enabled and VM running?
    After analyzing all provided reports, it looks like one of Windows services consumes very high CPU - CompatTelRunner.exe
    We recommend you to try disabling this service (https://windowslibrary.org/how-to-fix-high-cpu-disk-usage-by-compattelrunner-exe/) and check how VM behaves then with Parallels hypervisor. Looking forward to your updates.
     
  16. KorkyPlunger

    KorkyPlunger Kilo Poster

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    Sure. I filed technical report 314315485 this morning running under the Apple Hypervisor. This shows the CompatTellRunner.exe running. It uses around 3-9% CPU under the apple hypervisor, as compared to close to 100% under the parallels hypervisor.

    When I get a chance I'll try to disable the Microsoft Compatibility Telemetry (CompatTelRunner.exe) and see if that helps under the parallels hypervisor.
     
    Dmitry@Parallels likes this.
  17. KorkyPlunger

    KorkyPlunger Kilo Poster

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    @Dmitry@Parallels:

    Disabling Microsoft Compatibility Telemetry (CompatTelRunner.exe) does fix the issue where CompatTelRunner.exe is using high CPU under the Parallels hypervisor (which makes sense, because it no longer runs). However, the Parallels Hypervisor does seem to use much higher CPU in general; in my experience this anecdotally seems to occur during or immediately after a lot of I/O operations such as file scanning/reading/writing.

    A good example is when I start up Visual Studio on the guest OS. When it starts up, one of its plugins scans a whole bunch of files to index them. Under the parallels hypervisor, this uses 40-80% of the CPU for several minutes (I filed technical data #314658188 when this was occurring). Under the Apple Hypervisor, this uses 8-20% CPU and for a much shorter time period (I filed technical data #314660031 when running under the apple hypervisor with exactly the same apps open in the same scenario).

    So it seems there's still some work to do to get the Parallels hypervisor performing as well as the Apple one.
     
  18. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Huge thank for your help, @KorkyPlunger! Forwarded to Engineering team.
     
  19. KorkyPlunger

    KorkyPlunger Kilo Poster

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    @Dmitry@Parallels if your team would like to do a side-by-side comparison of technical data from when my VM is under heavy load due to the Windows Compatibility Telemetry running, I just had it happen under the Apple hypervisor, and filed data report #315758553

    This can be compared with Technical Data report #313738006 which is the same scenario but under the Parallels hypervisor, where the VM locks up for minutes at a time and is unusable.

    Please note: in the notes I added when sending the technical data, I accidentally referred to report 314315485 when I meant 313738006 -- I hope that doesn't confuse the dev team.
     
  20. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Thanks a lot, @KorkyPlunger, forwarded to respective engineers!
     

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