+ Post New Thread
Results 1 to 2 of 2
  1. #1
    Newbie level 2
    Points: 60, Level: 1

    Join Date
    Nov 2019
    Posts
    2
    Helped
    1 / 1
    Points
    60
    Level
    1

    SMP Affinity Changing?

    I'm working with the SMP affinity on an i.MX8 system (on a SolidRun HummingBoard Plus) and there are a couple of things that confuse me, but mostly that one of the affinities keeps changing.

    It's for a timer interrupt, e.g.:

    Code:
    root@sr-imx8:~# cat /proc/irq/6/smp_affinity
    4
    root@sr-imx8:~# cat /proc/irq/6/smp_affinity
    2
    root@sr-imx8:~# cat /proc/irq/6/smp_affinity
    2
    root@sr-imx8:~# cat /proc/irq/6/smp_affinity
    1
    Anyone got any insight into this? I can't find anything on the web that explains any more about affinity than the basics.

    It's a timer interrupt, if that makes any difference:

    Code:
    root@sr-imx8:~# grep -w 6: /proc/interrupts 
      6:      12833      12095      10157          1  GPC-PSCI  47 Edge      iMX system counter timer

    •   AltAdvertisement

        
       

  2. #2
    Newbie level 3
    Points: 30, Level: 1

    Join Date
    Mar 2020
    Posts
    4
    Helped
    0 / 0
    Points
    30
    Level
    1

    Re: SMP Affinity Changing?

    did you tried to force the affinity to a specific cpu ?

    Maybe, being imx8 a big.LITTLE stuff, the affinity is just moved depending on active cores.

    There are a lot of interrupt/affinity tutorial around but just basics. Looks like only thing to do to clarify more is entering the sources.



--[[ ]]--