Hello.  If I type "ps ax" (Suse 10.2) I see the following process,
among others:

PID TTY      STAT   TIME COMMAND
2 ?        S      0:00 [migration/0]

What is the [migration/0] process all about?  It has a thread type of
SCHED_FIFO and a priority of 99 (the highest, typing "ps -eLo
pid,tid,class,rtprio,fname" will reveal this).  I am wondering if it
is interfering with my own SCHED_FIFO threads, because I am not
getting good timing (sometimes 0.5 second delays)

Thanks!

Jim Beck

p.s. I am interested in using Linux in as near real-time as it can be
without a lot of hassle.  I have actually installed 2.6.19 kernel
source and Ingo Molnar et all rt patch 2.6.19-rt2 and I have booted
this kernel on top of the Suse 10.2 root file system to see how it
goes.  If anyone has any real steps on how to make Linux real-time
without hassle I'd love to hear more!

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4805455@gmail.com wrote:
> Hello.  If I type "ps ax" (Suse 10.2) I see the following process,
> among others:
>
>   PID TTY      STAT   TIME COMMAND
>     2 ?        S      0:00 [migration/0]
>
> What is the [migration/0] process all about?

It's a kernel thread responsible for moving threads between CPU's. It's
part of the kernel scheduler.

>  It has a thread type of
> SCHED_FIFO and a priority of 99 (the highest, typing "ps -eLo
> pid,tid,class,rtprio,fname" will reveal this).  I am wondering if it
> is interfering with my own SCHED_FIFO threads, because I am not
> getting good timing (sometimes 0.5 second delays)

Al kernel threads have this. It's unlikely that it will interfere with
your userspace threads.



Igmar

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