lkml.org 
[lkml]   [2002]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Alsa-devel] Re: Playback stutters - Correction
On Wed, Mar 20, 2002 at 03:06:56AM -0500, Paul Davis wrote:
> >CORRECTION:
> >Just retested with full hdparm (added -u setting) settings on
> >2.4.19-pre3-ac+preempt, and no skipping with above activities. This
> >seems pretty good.
> >
> >I could generate skips when switching from X to text console. Could not
> >generate skip when cycling virtual desktops within X (at high key repeat
> >rate). Again this seems pretty good.
>
> this is a know deficiency in the vt "driver", and is noted in Andrew
> Morton's "Things Not To Do" while requiring low scheduling latency. it
> would be nice if the vt code was fixed sometime, but right now, i
> think it can cause a scheduling delay for up to about 50ms.
>
> btw, i think it is still the case the Andrew's patch provides more
> reliable and lower absolute latency than the preemption patch.

It might do, but I couldn't compile it against 2.4.19-pre3-ac3, and with
the three hdparm parameters, I was still generating skips on 2.4.18+akm
with just file copying.

When 2.4.19 proper is out I'll do the rounds again when the patches
are available (and, in time, figure out how to use a proper latency
measuring tool - so my test reports might become useful to someone other than
myself).

Lock-break patch also didn't apply to 2419pre3ac3 either. Anyway, I can
play mp3s which is a starting point for me. Next I need to get a
hammerfall 9652 card working in a desktop so my band can start digital
recording.

I had read akm's 'things not to do' but for some reason missed the
hdparm stuff.

In summary, what is currently working for me: on a new DELL
Inspiron 8100 laptop, Maestro 3i sound, 1GHz Pentium ('Pentium III' I
assume), 60G HDD, Radeon Mobility 7500 64MB, DRI and framebuffer compiled into
kernel:

Linux 2.4.19-pre3-ac3 + preemptible kernel patch

hdparm -c 1 -d 1 -u 1 /dev/hda

Thanks for everything,
zen

-
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 13:25    [W:0.041 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site