14 Aug
2003
14 Aug
'03
5:02 p.m.
On Thursday 14 August 2003 15.59, Takashi Iwai wrote:
At Thu, 14 Aug 2003 02:55:28 +0300 (EEST),
Kai Vehmanen wrote:
My monitor can do this too. But you need to have that running.
It degrades ALL SCHED_FIFO/RT processes to SCHED_OTHER
on overuse - processes that do run as root could be protected. (FUTURE)
For example, one new approach to the problem
SCHED_SOFTRR, see:
http://www.xmailserver.org/linux-patches/softrr.html
http://www.ussg.iu.edu/hypermail/linux/kernel/0307.1/1729.html
It's unlikely to get something like this enabled by default in the
vanilla kernel, but we might be able to get a kernel option (no
patching!). But, but, as you can see from the discussion, they are
talking about totally different things (how XMMS/realplayer performs)...
... basicly a way to get benefits of SCHED_FIFO but without need for root
privileges. Now we just need to push these to the standard kernel
somehow.
i think the most benifit of soft-RR is that it doesn't bring your box
hanging up even if a RT-process gets into an infinite loop. this will
help to sort out the problem when a JACK system freezes with
SCHED_FIFO. (i.e. if it happens with soft-RR, it's a kernel/driver
bug :)
running by the normal user is an additional gift, for my eyes.
such a feature can be implemented with a wrapper (library), too,
as jackstart does.
You can request SCHED_FIFO/RT from my monitor.
Current implementation is working but it can be improved!
It uses static allocations intentionally.
The problem is to get it accepted - should it be added to jack(d)?
/RogerL
--
Roger Larsson
Skellefteå
Sweden