lkml.org 
[lkml]   [2004]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0
On Wed, 27 Oct 2004 12:29:21 +0200
Ingo Molnar <mingo@elte.hu> wrote:

> > pid 1286's current scheduling policy: SCHED_OTHER
> > pid 1286's current scheduling priority: 0
> > ~$ chrt -p 1287
> > pid 1287's current scheduling policy: SCHED_OTHER
> > pid 1287's current scheduling priority: 0
>
> just curious, are these two important to the latency path of jackd, or
> are they lowprio things and are thus at SCHED_OTHER intentionally?

the latter. jackd has one RT thread for doing the grunt work and one which
acts as a watchdog. The other two are SCHED_OTHER by design.

> > Anyways i get xruns like crazy under load (like 200 in 10 minutes). It
> > seems the scheduling class and high priority don't matter really as
> > wiggling windows around on the screen or doing a "find /" can easily
> > provoke xruns.
>
> yeah, i'm hunting a quite similar bug: i can see 'realfeel' latencies
> generated by simple window scrolling. It is most likely a logic bug
> somewhere - a missing reschedule check, irqs left disabled accidentally,
> or something like that. Since some other workloads dont trigger it i
> dont think i broke RT scheduling by itself - it is most likely some
> non-core code somewhere missing a resched. Which doesnt make it less of
> a problem, but it makes it harder to find :-|

Hmm, you're right. It seems that diskload alone doesn't trigger the problem.
it rather looks like graphics output/activity is the problem.

Anyways i'm back in U3 w/o PREEMPT_REALTIME as V0.3.2 just hardlocked on me
when i pressed ctrl-d in a root shell (in an xterm) to exit. Nothing has
made it to the log. I haven't found out yet whether it's possible to use my
old zx81 as serial console, so i can't help with OOPS/BUG output.

flo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:1.396 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site