lkml.org 
[lkml]   [2003]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: 2.6 vs 2.4 regression when running gnomemeeting
    From
    Date
    On Sat, 2003-12-20 at 04:50, Nick Piggin wrote:
    > Christian Meder wrote:
    >
    > >On Sat, 2003-12-20 at 03:55, Con Kolivas wrote:
    > >
    > >>On Sat, 20 Dec 2003 13:38, Nick Piggin wrote:
    > >>
    > >>>Christian Meder wrote:
    > >>>
    > >>>>On Sat, 2003-12-20 at 02:26, Nick Piggin wrote:
    > >>>>
    > >>>>>Christian Meder wrote:
    > >>>>>
    > >>>>>>On Sat, 2003-12-20 at 01:48, Nick Piggin wrote:
    > >>>>>>
    > >>>>>>>Sounds reasonable. Maybe its large interrupt or scheduling latency
    > >>>>>>>caused somewhere else. Does disk activity alone cause a problem?
    > >>>>>>>find / -type f | xargs cat > /dev/null
    > >>>>>>>how about
    > >>>>>>>dd if=/dev/zero of=./deleteme bs=1M count=256
    > >>>>>>>
    > >>>>>>Ok. I've attached the logs from a run with a call with only an
    > >>>>>>additional dd. The quality was almost undisturbed only very slightly
    > >>>>>>worse than the unloaded case.
    > >>>>>>
    > >>Since so many things have actually changed it's going to be hard to extract
    > >>what role the cpu scheduler has in this setting, but lets do our best.
    > >>
    > >>Is there a reason you're running gnomemeeting niced -10? It is hardly using
    > >>any cpu and the problem is actually audio in your case, not the cpu
    > >>gnomemeeting is getting. Running dependant things (gnomemeeting, audio
    > >>server, gnome etc) at different nice levels is not a great idea as it can
    > >>lead to priority inversion scenarios if those apps aren't coded carefully.
    > >>
    > >>What happens if you run gnomemeeting at nice 0?
    > >>
    > >
    > >Exactly the same. It was only reniced to -10 because I tried it and
    > >forgot to set it back. With your scheduler renicing doesn't make a
    > >difference. No matter if I renice the compile to 19 or gnomemeeting to
    > >-10. With Nick's scheduler renicing gnomemeeting to -10 improves the
    > >situation.
    > >
    >
    > (although not much Con)

    right. Ok I'm running now 2.6.0 with Nick's v28p1: The results without
    load and with kernel compile load are attached. On nice level 0 I get
    now the stuttering sound which I described in the previous mail. When I
    renice gnomemeeting to -10 it's actually usable but not as good as in
    2.4.2x. It's still sensitive to window movement and X activity. Two
    subjective observations are that the nice levels haven't got such a big
    impact in Nick's scheduler they used to have and that the default
    behaviour gnomemeetingwise is better than in earlier Nick schedulers.

    > >
    > >>How is your dma working on your disks?
    > >>
    > >
    > >/dev/hda:
    > > multcount = 0 (off)
    > > IO_support = 0 (default 16-bit)
    > > unmaskirq = 0 (off)
    > > using_dma = 1 (on)
    > > keepsettings = 0 (off)
    > > readonly = 0 (off)
    > > readahead = 256 (on)
    > > geometry = 65535/16/63, sectors = 117210240, start = 0
    > >
    >
    > This might be a problem - try turning unmaskirq on, and possibly
    > 32-bit IO support on (hdparm -u1 -c1 /dev/hda). I think there is
    > a remote possibility that doing this will corrupt your data just
    > to let you know.

    Tried it and doesn't make a difference.

    > >
    > >>What happens if you don't use an audio server (I'm not sure what the audio
    > >>server is in gnome); or if you're not using one what happens when you do?
    > >>
    > >
    > >esd was running but I'm not sure gnomemeeting with ALSA support was
    > >using it. After killing esd and retrying there was no difference.
    > >
    >
    > So the 1 gnomemeeting process is doing everything? (except display of
    > course)

    AFAIK yes.


    Christian

    > >
    > >>Renice the audio server instead?
    > >>
    > >
    > >gnomemeeting without audio server is showing the same phenomenon like
    > >gnomemeeting with esd.
    > >
    > >
    > >>You've already tried different audio drivers right?
    > >>
    > >
    > >Yes, the phenomenon occurs for the OSS and the ALSA driver.
    > >
    > >
    > >>Nice the compile instead of -nicing the other stuff.
    > >>
    > >
    > >Tried it with same result (see above).
    > >
    > >
    > >>Try the minor interactivity fix I posted only yesterday for different nice
    > >>level latencies:
    > >>http://ck.kolivas.org/patches/2.6/2.6.0/patch-2.6.0-O21int
    > >>
    > >
    > >Actually all the posted results were on a 2.6.0-test11-mm1 with your
    > >patch added on top. So the patch didn't change anything for me.
    > >
    > >
    > >>Is your network responsible and the audio unrelated? Some have reported
    > >>strange problems with ppp or certain network card drivers?
    > >>
    > >
    > >The problem occurs whether I use my WLAN PCMCIA card or my PCMCIA
    > >Ethernet card.
    > >
    > >
    > >>As you see it's not a straight forward problem but there's some things for you
    > >>to get your teeth stuck into. As it stands the cpu scheduler from your top
    > >>output appears to be giving appropriate priorities to the different factors
    > >>in your equation.
    > >>
    > >
    > >I know that the problem isn't straight forward that's why I refrained a
    > >long time before posting to linux-kernel trying to rule out different
    > >scenarios. As it stands I tried different gnomemeeting versions,
    > >different audio drivers, different nice levels, different schedulers,
    > >preemption on and off, ACPI on and off, -mm kernels and pristine Linus
    > >kernels with no luck. If I put CPU load on my box the gnomemeeting
    > >audiostream gets badly mutilated (unusable). There's not much left I can
    > >think of that's why I'm finally posting to linux-kernel.
    > >
    >
    > Thanks for your effort.
    >
    --
    Christian Meder, email: chris@onestepahead.de

    What's the railroad to me ?
    I never go to see
    Where it ends.
    It fills a few hollows,
    And makes banks for the swallows,
    It sets the sand a-blowing,
    And the blackberries a-growing.
    (Henry David Thoreau)




    [unhandled content-type:application/x-bzip][unhandled content-type:application/x-bzip]
    \
     
     \ /
      Last update: 2005-03-22 13:59    [W:0.034 / U:2.256 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site