Find the answer to your Linux question:
Results 1 to 4 of 4
Hello, I am a new linux forum member. I use RedHat Enterprise 4.0. I have a question about how Linux in general and RedHat/Fedora in particular manage Hyperthreading on Intel ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Just Joined!
    Join Date
    May 2005
    Posts
    3

    Managing Hyperthreading on Linux


    Hello,

    I am a new linux forum member.

    I use RedHat Enterprise 4.0.

    I have a question about how Linux in general and RedHat/Fedora in particular manage Hyperthreading on Intel Xeon processors.

    I think that in Windoz, they claim that they enable/disable it according to the workload present. I think, this is because the processor gets split into two logical processors and some hardware structures are cut into half.

    Is there anyway to change hyperthreading on the fly while OS is running without a reboot and then enable/disable it from bios.

    Hameed.

  2. #2
    Linux Guru lakerdonald's Avatar
    Join Date
    Jun 2004
    Location
    St. Petersburg, FL
    Posts
    5,035
    You mean enable/disable it?

  3. #3
    Just Joined!
    Join Date
    May 2005
    Posts
    3

    Re: HT Enable/Disable?

    I mean for the OS to Enable/Disalbe it while it is originally is enabled in the BIOS.

    i.e. no BIOS work is done after you first enable it.

    i.e. the OS would be intelligent enough to enable/Disable HT on the fly according to the tasks running on the machine now.

    Imagine a server running one big task only and remins like this for long, why would you want HT if the task is single-threaded.

    Also, imagine having multiple of these why would you run in non-HT mode while you make faster progress with HT.

  4. #4
    Linux Guru lakerdonald's Avatar
    Join Date
    Jun 2004
    Location
    St. Petersburg, FL
    Posts
    5,035
    Yeah, I run an HT Server, and Linux seems pretty good about this. Just make sure to enable SMP in the kernel config, and the kernel scheduler does a good job of splitting load between the two cores, and knowing when/when not to.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •