From: Thomas Martitz <kugel_at_rockbox.org>
Date: Wed, 30 Nov 2011 13:43:16 +0100

Am 30.11.2011 13:35, schrieb Thomas Jarosch:
> Hi,
>
> I just noticed a performance regression with rockbox 3.10
> compared to rockbox 3.9 on the Nokia N900.

FWIW, IMO you shouldn't use the release versions/terms for RaaA/Maemo as
3.10 (or any previous release) isn't released for it. Releases apply
only to stable targets and have no meaning whatsoever for
unstable/unusable ones. There's simply no 3.9 or 3.10 for those.

> CPU usage increased by 15 to 20 percent when playing
> back a mp3 file. To verify it I downgraded to 3.9,
> watched the "top" output and upgraded to 3.10 again,
> always playing back the same mp3 file.
>
> Audio playback on maemo 5 is handled by gstreamer / pulseaudio.
> I can see an even increase in CPU usage both on the
> running rockbox binary and the pulseaudio daemon.
>
> Vague guess: The PCM buffer is passed in smaller chunks
> to the OS in 3.10 and therefore causing more handling overhead.
>
>

There was a work in that area for the software mixer. Perhaps that's the
reason? The chunk size was about 32K before that work. Don't know the
current value.

Best regards.
Received on 2011-11-30