Re: Low latency kernel in Karmic to help with PulseAudio?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Wed, 6 May 2009, I wrote: For Hardy, this was a significant problem. New versions of ALSA necessary for improved PulseAudio integration were released immediately after 8.04 released. And it has happened again - ALSA 1.0.20 was released hours ago. -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) iD8DBQFKAaqye9GwFciKvaMRAmSZAKCNNbckqdKu76FWc31F0GhdYluGugCgipIM bMm7vbwbAtaPzzy0vojMW30= =5+NG -END PGP SIGNATURE- -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Low latency kernel in Karmic to help with PulseAudio?
Hello, Whilst participating in the Karmic forums, I remembered a discussion about some distros like Fedora running a low-latency kernel which helped with PulseAudio. Is there going to be discussion during UDS amongst yourselves (devs) about enabling low-latency for Karmic as well? See this mailing list post by Lennart of PulseAudio/Fedora fame: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-February/003150.html And, I wonder if enabling low-latency mode also improves responsiveness of the user desktop... Regards, Vishal -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Re: Low latency kernel in Karmic to help with PulseAudio?
On Martes 05 Mayo 2009 9:28:20 PM Vishal Rao wrote: Hello, Whilst participating in the Karmic forums, I remembered a discussion about some distros like Fedora running a low-latency kernel which helped with PulseAudio. Is there going to be discussion during UDS amongst yourselves (devs) about enabling low-latency for Karmic as well? See this mailing list post by Lennart of PulseAudio/Fedora fame: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009- February/003150.html And, I wonder if enabling low-latency mode also improves responsiveness of the user desktop... A real-time (-rt) kernel is available and has been for at least a few releases. PREEMPT (which Lennart says would help) was enabled once upon a time, but I think it was disabled due to high laptop battery usage or something like that. After that email from Lennart, discussion about it came up again, but it was way too late in Jaunty's cycle to be changed by that point. But uh yeah...I do intend to at least bring it up at UDS and see what the kernel team says. -- Mackenzie Morgan http://ubuntulinuxtipstricks.blogspot.com apt-get moo signature.asc Description: This is a digitally signed message part. -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Re: Low latency kernel in Karmic to help with PulseAudio?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Wed, 6 May 2009, Vishal Rao wrote: Is there going to be discussion during UDS amongst yourselves (devs) about enabling low-latency for Karmic as well? Yes. See this mailing list post by Lennart of PulseAudio/Fedora fame: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-February/003150.html One thing to keep in mind (that I've raised to other developers) is that Ubuntu tends to release with slightly older versions of software in the audio stack. This tends to complicate development and troubleshooting of audio problems. FeatureFreeze has been early enough to prevent updating ALSA (think kernelspace and userspace sync) and PulseAudio, both of which contribute quite heavily to user experience. For Hardy, this was a significant problem. New versions of ALSA necessary for improved PulseAudio integration were released immediately after 8.04 released. The best that could have been done would have been to configure PulseAudio to use dmix and dsnoop devices to work around the massive breakage that ensued. Of course that approach runs afoul of Lennart's strident recommendations that only hw be used. For Jaunty, we again encountered the situation where significant linux patches were necessary to prevent disastrous regressions from Intrepid's user experience, and of course these patches were developed and tested extremely late in the 9.04 cycle. Testing and tweaking of these fixes is ongoing (see the linux SRU), with many indications that all levels of the stack need to be realigned to resolve PulseAudio's behaviour. (It's worth noting that several pieces need to be aligned in Karmic: linux; - needs to remain synced with alsa-lib; alsa-plugins; pulseaudio) The Karmic development schedule has some points at which these syncs can be evaluated, and hopefully 9.10 will have the necessary pieces in place. Once there are devoted developers for these tasks, the user experience should improve noticeably. Dan -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) iD8DBQFKARzte9GwFciKvaMRAlv+AJ4hXzSOLBvEZPdp0bQ+ylQjK/cLHACbBx0i xjmZAWphkr2N+fcNweiUCU8= =b73s -END PGP SIGNATURE- -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Re: Low latency kernel in Karmic to help with PulseAudio?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Wed, 6 May 2009, Mackenzie Morgan wrote: A real-time (-rt) kernel is available and has been for at least a few releases. PREEMPT (which Lennart says would help) was enabled once upon a time, but I think it was disabled due to high laptop battery usage or something like that. After that email from Lennart, discussion about it came up again, but it was way too late in Jaunty's cycle to be changed by that point. Not to mention that users of -rt tend to avoid PulseAudio rather emphatically. In fact, Launchpad carries at least one bug where performance with -rt is poor when PulseAudio is used (whereas -generic fares better). Really, the RT patches make the kernel a completely different beast. Luckily the necessary mid-layer ALSA fixes uncovered late in the 9.04 cycle positively affect both -generic and -rt. Testing Karmic with newer - -rt, ALSA, and PulseAudio is going to be a joyride indeed. Dan -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) iD8DBQFKAR9xe9GwFciKvaMRAoGYAJ9zmjbGRHsybFBcn2mxq2CeCRJN5ACgnONF Wx1hGWQv3iZw0urq/w1vVnM= =p5t1 -END PGP SIGNATURE- -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
