Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
On Tue, 13 Mar 2007 11:45:50 -0600 "Chris Friesen" <[EMAIL PROTECTED]> wrote: > Lee Revell wrote: > > > Sounds like Wengophone is broken. It should be using RT threads for > > time critical work, as JACK and Ardour2 are doing. > > If the app has root privileges to set RT policy, then it could also set > deeply negative nice values as well. > > Doesn't reallly help the regular user with no privileges. > > Chris Well my distro (Arch) does have the relevant PAM support for giving users realtime capabilities, but naturally Wengophone is not designed to make use of them (does any internet phone do this?). The main problem is that it worked fine on mainline and does not with RSDL, and even boosting it to nice -19 (with root privs) makes no difference (although I only tested nice -19 with the slightly dodgy patch Con posted for Mike Galbraith, that patch reportedly only affects a few positive nice values). Two possibilities occur to me: 1. RSDL just isn't giving sched_other tasks as low latency as mainline (Wengophone is not using much CPU time from as far as top can tell). 2. The problem is actually caused by increased network latency somehow caused by RSDL (this is an internet phone). I would like to add that the problem seems to be latency *spikes* that occur when there is sudden activity in another app (say, I open a folder in nautilus) that was previously largely idle. I suppose if Con does what he says and reduces latency overall, this problem might disappear. For now, of course, I hope his neck gets better :) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
On 3/13/07, Chris Friesen <[EMAIL PROTECTED]> wrote: Lee Revell wrote: > Sounds like Wengophone is broken. It should be using RT threads for > time critical work, as JACK and Ardour2 are doing. If the app has root privileges to set RT policy, then it could also set deeply negative nice values as well. Doesn't reallly help the regular user with no privileges. Well this was supposed to be solved by RLIMIT_NICE and RLIMIT_RTPRIO which went into mainline about a year ago but distros have been very slow to pick up the new PAM, glibc and bash packages. We don't have a clear picture yet of what defaults the distros will ship. Lee - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
Lee Revell wrote: Sounds like Wengophone is broken. It should be using RT threads for time critical work, as JACK and Ardour2 are doing. If the app has root privileges to set RT policy, then it could also set deeply negative nice values as well. Doesn't reallly help the regular user with no privileges. Chris - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
On 3/13/07, Ash Milsted <[EMAIL PROTECTED]> wrote: Desktop use whilst talking on Wengophone (run at nice -5): Under RSDL some GUI use e.g. opening a new folder in nautilus causes pops (buffer underruns) which do not occur with mainline. I suppose the changes in RSDL might require a lower nice value for equivalent performance, but (as a user) I am limited to -5. Low-latency audio with JACK and Ardour2: Rock-solid performance with either scheduler.. realtime works nicely. Sounds like Wengophone is broken. It should be using RT threads for time critical work, as JACK and Ardour2 are doing. No scheduler can help if the apps are not correctly written... Lee - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
On Wednesday 14 March 2007 02:35, Ash Milsted wrote: > Here's my experience with RSDL 0.30 on 2.6.21-rc3-git6 under my normal > usage scenarios... > > Plain desktop use (web browsing, music, etc): no noticeable change > > Desktop use during kernel compile (no -j): The compile impacts desktop > use more with RSDL, but this is easily solved by nice-ing the compile > (default nice of 10 seems enough). The kind of impact I am talking about > is e.g. occasional delays in scrolling in the browser etc. > > Desktop use whilst talking on Wengophone (run at nice -5): Under RSDL > some GUI use e.g. opening a new folder in nautilus causes pops (buffer > underruns) which do not occur with mainline. I suppose the changes in > RSDL might require a lower nice value for equivalent performance, but > (as a user) I am limited to -5. > > Low-latency audio with JACK and Ardour2: Rock-solid performance with > either scheduler.. realtime works nicely. > > Playing Quake3 (proprietary nvidia driver): Plays smoothly for both > schedulers. > > So, I suppose I'd like to know what to do about the Wengophone issue, > because that really is a problem for me. I guess your re-worked -ive > nice values might help? Well the change to -nice values was to minimise the harm they do to everything else. They will still get the lowest latencies and the most cpu but no more than previously. The difference will be to more niced tasks. I'm not sure just how much cpu you require for wengophone because at -5 it would be getting a fair chunk of cpu with the RSDL 0.30. Anyway, by sheer coincidence I just emailed out that patch I was planning so feel free to try it. -- -ck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [ck] RSDL v0.30 cpu scheduler for mainline kernels
On Mon, 12 Mar 2007 10:58:11 +1100 Con Kolivas <[EMAIL PROTECTED]> wrote: > There are updated patches for 2.6.20, 2.6.20.2, 2.6.21-rc3 and 2.6.21-rc3-mm2 > to bring RSDL up to version 0.30 for download here: > > Full patches: > > http://ck.kolivas.org/patches/staircase-deadline/2.6.20-sched-rsdl-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.20.2-rsdl-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.21-rc3-sched-rsdl-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.21-rc3-mm2-rsdl-0.30.patch > > incrementals: > > http://ck.kolivas.org/patches/staircase-deadline/2.6.20/2.6.20.2-rsdl-0.29-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.20.2/2.6.20.2-rsdl-0.29-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.21-rc3/2.6.21-rc3-rsdl-0.29-0.30.patch > http://ck.kolivas.org/patches/staircase-deadline/2.6.21-rc3-mm2/2.6.21-rc3-mm2-rsdl-0.29-0.30.patch > > -- > -ck > ___ > http://ck.kolivas.org/faqs/replying-to-mailing-list.txt > ck mailing list - mailto: [EMAIL PROTECTED] > http://vds.kolivas.org/mailman/listinfo/ck Here's my experience with RSDL 0.30 on 2.6.21-rc3-git6 under my normal usage scenarios... Plain desktop use (web browsing, music, etc): no noticeable change Desktop use during kernel compile (no -j): The compile impacts desktop use more with RSDL, but this is easily solved by nice-ing the compile (default nice of 10 seems enough). The kind of impact I am talking about is e.g. occasional delays in scrolling in the browser etc. Desktop use whilst talking on Wengophone (run at nice -5): Under RSDL some GUI use e.g. opening a new folder in nautilus causes pops (buffer underruns) which do not occur with mainline. I suppose the changes in RSDL might require a lower nice value for equivalent performance, but (as a user) I am limited to -5. Low-latency audio with JACK and Ardour2: Rock-solid performance with either scheduler.. realtime works nicely. Playing Quake3 (proprietary nvidia driver): Plays smoothly for both schedulers. So, I suppose I'd like to know what to do about the Wengophone issue, because that really is a problem for me. I guess your re-worked -ive nice values might help? Ash - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
