The network speed of System Monitor cannot be shown in Ubuntu 14.04

As @Aditya and @Bryan suggested, this is the bug in kernel, and it can be fixed by update kernel.

For example: My system is Ubuntu 14.04. The version of kernel is 3.13.0, and the system is 64bit (amd64).

They all can be got by commands as blew:

┌─ (marslo@MarsloJiao ~) ->
└─ $ uname -r
3.13.0-30-generic

OR

┌─ (marslo@MarsloJiao ~) ->
└─ $ dpkg -l | grep "linux\-[a-z]*\-"
ii  linux-headers-3.13.0-24                               3.13.0-24.47                                        all          Header files related to Linux kernel version 3.13.0                                                                          
ii  linux-headers-3.13.0-24-generic                       3.13.0-24.47                                        amd64        Linux kernel headers for version 3.13.0 on 64 bit x86 SMP                                                                    
ii  linux-headers-3.13.0-30                               3.13.0-30.55                                        all          Header files related to Linux kernel version 3.13.0
ii  linux-headers-3.13.0-30-generic                       3.13.0-30.55                                        amd64        Linux kernel headers for version 3.13.0 on 64 bit x86 SMP
ii  linux-headers-generic                                 3.13.0.30.36                                        amd64        Generic Linux kernel headers
ii  linux-image-3.13.0-24-generic                         3.13.0-24.47                                        amd64        Linux kernel image for version 3.13.0 on 64 bit x86 SMP
ii  linux-image-3.13.0-30-generic                         3.13.0-30.55                                        amd64        Linux kernel image for version 3.13.0 on 64 bit x86 SMP
ii  linux-image-extra-3.13.0-24-generic                   3.13.0-24.47                                        amd64        Linux kernel extra modules for version 3.13.0 on 64 bit x86 SMP
ii  linux-image-extra-3.13.0-30-generic                   3.13.0-30.55                                        amd64        Linux kernel extra modules for version 3.13.0 on 64 bit x86 SMP
ii  linux-image-generic                                   3.13.0.30.36                                        amd64        Generic Linux kernel image
ii  linux-libc-dev:amd64                                  3.13.0-30.55                                        amd64        Linux Kernel Headers for development
ii  linux-sound-base                                      1.0.25+dfsg-0ubuntu4                                all          base package for ALSA and OSS sound systems

So, the following steps can fix the problem:

1. there are three deb packages should be downloaded from /~kernel-ppa/mainline/v3.14.1-trusty first:

   • linux-headers-.*_amd64.deb (linux-headers-3.14.1-031401-generic_3.14.1-031401.201404141220_amd64.deb)
   • linux-headers-.*all.deb (linux-headers-3.14.1-031401_3.14.1-031401.201404141220_all.deb)
   • linux-image-.*amd64.deb (linux-image-3.14.1-031401-generic_3.14.1-031401.201404141220_amd64.deb)

2. Install all these debs

   • $ sudo dpkg -i *.deb

3. Reboot your system

   • $ sudo reboot

Bingo! The network speed back to the system monitor!!