[linux-audio-dev] Realtime audio and IO schedulers

Cal hihone at bigpond.net.au
Sat Jan 22 23:54:35 UTC 2005


Florian Schmidt wrote:
> Thanks for the pointers. I will give it a try :)
> 
> Btw: i read this mail of yours in the archives:
> 
> ------
>> When running jack_test4.1 with LD_ASSUME_KERNEL=2.4.19 set, schedtool 
>> shows all the appropriate threads as sched_iso.  Without 
>> LD_ASSUME_KERNEL set, there isn't a sched_iso thread to be seen. They 
>> all appear to be sched_normal.
> ----- 
> This smells much like the classic nptl-hell some jackd users
> experienced. See this page:

Indeed it does, so let's not stir it up again unnecessarily!
Lee & joq on jack-devel sorted me out nicely on that one. I normally run
with LD_ASSUME_KERNEL set, but it got overlooked/omitted on one script.
  Everthing seemed to be working right, but schedtool didn't show the
class as expected.  It seems to be no more than a schedtool quirk when
running with NPTL (accidentally). As guided by joq,
   ps -eLo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
showed things were cool and as expected, even with NPTL.

cheers, Cal





More information about the Linux-audio-dev mailing list