Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Ubuntu 16TLS 64-bit Anyone ever experienced SUPER slow application startup times?
Qt 6.11 is out! See what's new in the release blog

Ubuntu 16TLS 64-bit Anyone ever experienced SUPER slow application startup times?

Scheduled Pinned Locked Moved Solved General and Desktop
12 Posts 5 Posters 3.1k Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • dheerendraD Offline
    dheerendraD Offline
    dheerendra
    Moderators Qt Champions 2024 Qt Champions 2022 Qt Champions 2017
    wrote on last edited by
    #2

    Looks like this is more of question in ubuntu forum. I'm sure u will get the right answer in ubuntu forum

    Dheerendra
    @Community Service
    Certified Qt Specialist
    https://www.pthinks.com

    1 Reply Last reply
    0
    • V Offline
      V Offline
      VRHans
      wrote on last edited by
      #3

      I posted it here because everything else I build (OpenGL applications specifically) runs just fine on the same Ubuntu platform. My Golang code runs fine, a test non-Qt GTK C++ application starts and works fine, and all the pre-installed Ubuntu applications start and work fine. Ubuntu forums would tell me that if the only thing not working properly is my Qt application, I should post in Qt forum... ;)

      jsulmJ 1 Reply Last reply
      0
      • V VRHans

        I posted it here because everything else I build (OpenGL applications specifically) runs just fine on the same Ubuntu platform. My Golang code runs fine, a test non-Qt GTK C++ application starts and works fine, and all the pre-installed Ubuntu applications start and work fine. Ubuntu forums would tell me that if the only thing not working properly is my Qt application, I should post in Qt forum... ;)

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #4

        @VRHans In your first post you did not mention that your Qt app is starting slowly - it sounds like your Ubuntu is starting very slowly. You should formulate your questions more clearly to avoid such misunderstandings.

        What Qt version do you use and how did you install it?

        https://forum.qt.io/topic/113070/qt-code-of-conduct

        1 Reply Last reply
        0
        • V Offline
          V Offline
          VRHans
          wrote on last edited by
          #5

          Lol, Excellent point!

          Sorry everybody, I had been googling my rear off and asked the question in mid thought apparently.

          Apologies!

          Let me restate:. Ubuntu behaves normally in all regards except when I run my Qt application.

          Launching my Qt application can take from several minutes to 30 seconds. Every other platform, including other Linux distributions, startup is instantaneous.

          CPU monitoring during the long starts using top reports virtually zero CPU usage during this period. Then suddenly the app appears and everything works like normal.

          Repeated starts do not shorten the startup time.

          I don't want anybody spending a lot of time trying to figure this out, but I did want to know if this was something that was a known issue with Ubuntu.

          I suspect the problem is somehow related to a Unity and Parallels problem .

          Again, apologies @dheerendra

          jsulmJ 1 Reply Last reply
          0
          • V VRHans

            Lol, Excellent point!

            Sorry everybody, I had been googling my rear off and asked the question in mid thought apparently.

            Apologies!

            Let me restate:. Ubuntu behaves normally in all regards except when I run my Qt application.

            Launching my Qt application can take from several minutes to 30 seconds. Every other platform, including other Linux distributions, startup is instantaneous.

            CPU monitoring during the long starts using top reports virtually zero CPU usage during this period. Then suddenly the app appears and everything works like normal.

            Repeated starts do not shorten the startup time.

            I don't want anybody spending a lot of time trying to figure this out, but I did want to know if this was something that was a known issue with Ubuntu.

            I suspect the problem is somehow related to a Unity and Parallels problem .

            Again, apologies @dheerendra

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #6

            @VRHans You could try to start your app like this:

            strace ./myApp
            

            maybe you will see then where it spends all that time.

            https://forum.qt.io/topic/113070/qt-code-of-conduct

            V 1 Reply Last reply
            0
            • jsulmJ jsulm

              @VRHans You could try to start your app like this:

              strace ./myApp
              

              maybe you will see then where it spends all that time.

              V Offline
              V Offline
              VRHans
              wrote on last edited by
              #7

              Well, I think it's nothing to do with Qt thankfully. My application does a lot of crypto oriented work and apparently the static initialization at startup is unable to obtain enough entropy in order to get to main() until after several minutes or (laughingly) if I generate entropy through mouse/keyboard use - faster - LOL.

              I wonder if it's just a shortcoming of this particular Ubuntu/patch level. Anyhow, thanks for your time everybody! Entropy... LOL.

              JonBJ 1 Reply Last reply
              0
              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #8

                Hi
                ehh, so your app is literally minutes to start up as it hanging around to
                generate randomness and you can make that faster by generating events??
                Are you using a so/lib or something like that?
                Maybe it has issues/can be updated?

                1 Reply Last reply
                0
                • V VRHans

                  Well, I think it's nothing to do with Qt thankfully. My application does a lot of crypto oriented work and apparently the static initialization at startup is unable to obtain enough entropy in order to get to main() until after several minutes or (laughingly) if I generate entropy through mouse/keyboard use - faster - LOL.

                  I wonder if it's just a shortcoming of this particular Ubuntu/patch level. Anyhow, thanks for your time everybody! Entropy... LOL.

                  JonBJ Offline
                  JonBJ Offline
                  JonB
                  wrote on last edited by JonB
                  #9

                  @VRHans said in Ubuntu 16TLS 64-bit Anyone ever experienced SUPER slow application startup times?:

                  Well, I think it's nothing to do with Qt thankfully. My application does a lot of crypto oriented work and apparently the static initialization at startup is unable to obtain enough entropy in order to get to main() until after several minutes or (laughingly) if I generate entropy through mouse/keyboard use - faster - LOL.

                  I wonder if it's just a shortcoming of this particular Ubuntu/patch level. Anyhow, thanks for your time everybody! Entropy... LOL.

                  Given this, it's definitely nothing to do with Qt, and you would be much better posting to an Ubuntu forum or stackoverflow with your Linux code for best replies.

                  V 1 Reply Last reply
                  0
                  • JonBJ JonB

                    @VRHans said in Ubuntu 16TLS 64-bit Anyone ever experienced SUPER slow application startup times?:

                    Well, I think it's nothing to do with Qt thankfully. My application does a lot of crypto oriented work and apparently the static initialization at startup is unable to obtain enough entropy in order to get to main() until after several minutes or (laughingly) if I generate entropy through mouse/keyboard use - faster - LOL.

                    I wonder if it's just a shortcoming of this particular Ubuntu/patch level. Anyhow, thanks for your time everybody! Entropy... LOL.

                    Given this, it's definitely nothing to do with Qt, and you would be much better posting to an Ubuntu forum or stackoverflow with your Linux code for best replies.

                    V Offline
                    V Offline
                    VRHans
                    wrote on last edited by
                    #10

                    @JNBarchan Agreed, and there are several solutions to this (bind urandom/random, use rng-utils, or install haveged - which is what I do on servers.)

                    1 Reply Last reply
                    0
                    • JonBJ Offline
                      JonBJ Offline
                      JonB
                      wrote on last edited by
                      #11

                      @VRHans Have you thought of putting your PC into a cup of hot tea (good source of Brownian motion)? ;-)

                      1 Reply Last reply
                      0
                      • V Offline
                        V Offline
                        VRHans
                        wrote on last edited by
                        #12

                        I'm more likely to /dev/random -> bind -> /guinness/nitrogen/boycott-effect ;)

                        1 Reply Last reply
                        0

                        • Login

                        • Login or register to search.
                        • First post
                          Last post
                        0
                        • Categories
                        • Recent
                        • Tags
                        • Popular
                        • Users
                        • Groups
                        • Search
                        • Get Qt Extensions
                        • Unsolved