From: Joseph Zitt <joseph.zitt@gm...> - 2006-10-04 03:09:47
I'm now running Rosegarden 1.4 on my Ubuntu Dapper laptop. It's
working OK, though I can only use it with my laptop's built-in
soundcard -- while ALSA (and thus all my other sound apps) handles my
Digigram VxPocket flawlessly, JACK dies with xruns (I think -- the
messages are a bit cryptic) when I try to use it.
When I start up Rosegarden, I get the message "System timer resolution
is too low.
Rosegarden was unable to find a high-resolution timing source for MIDI
Following the page on studio preparation for Dapper on the Ubuntu Studio wiki
I set the resolution to their suggested value of 1024 by doing:
sudo sysctl -w dev.rtc.max-user-freq=1024
sudo su -c 'echo dev.rtc.max-user-freq=1024 >> /etc/sysctl.conf'
Should this be sufficient? Should I set it to a different value?
From: Chris Cannam <cannam@al...> - 2006-10-05 19:35:23
On Tuesday 03 Oct 2006 00:00, Joseph Zitt wrote:
> When I start up Rosegarden, I get the message "System timer
> resolution is too low. [...]
> Following the page on studio preparation for Dapper on the Ubuntu
> Studio wiki
> http://ubuntustudio.com/wiki/index.php/Dapper:Studio_Preparation I
> set the resolution to their suggested value of 1024 by doing:
> sudo sysctl -w dev.rtc.max-user-freq=1024
> sudo su -c 'echo dev.rtc.max-user-freq=1024 >> /etc/sysctl.conf'
> Should this be sufficient?
No. This sets the maximum selectable frequency for the system's
real-time clock interrupt. It has nothing to do with the kernel timer
that Rosegarden uses for MIDI timing. The advice on that page is
wrong, or at least placed in the wrong context.
I'm afraid the only way to change the value that Rosegarden's warning
message refers to is to recompile the kernel.
If you switched Rosegarden's sequencer timing source to "RTC timer",
then the setting you changed would in theory be relevant.
Unfortunately, at the moment all reports suggest that the main result
of this will be to lock up your system completely.