11 Mar
2004
11 Mar
'04
7:12 p.m.
On Thu, Mar 11, 2004 at 02:52:08PM -0600, Jack O'Quin wrote:
James Stone <stone1(a)btinternet.com> writes:
I have just done some further testing: using my SBLive, running muse and
zynaddsubfx through jack (started with qjackctl), if I set the nice
value of XFree86 to 0, I do not get xruns when switching workspaces or
opening a new terminal, but with a nice value of -20 I get several xruns
in both situations.. I can also get xruns running jackd as root and
opening several aterms while it is connected to hydrogen.
although with nice 0 it is close to usable, I still get xruns on
starting new programs connecting to jackd, whereas with 2.4.25/low
latency this does not occur.
James.
On Thu, Mar 11, 2004 at 06:21:15PM +0100, Frank
Barknecht wrote:
> Another thing to check would be your X
server's nice value. This used
> to be "-10" in older Debians, but should not be set at all with 2.6.
How disappointing.. I just tried this, and it
didn't help.. I was almost
sure this was going to work. I am still getting many more xruns than
with the low latency 2.4.x kernels though at least I am not getting
xruns on opening and closing windows!
However, on doing a top in 2.6.x I noticed that quite a few processes
are running with a nice of -10 (something called "event" among
others..). This does not appear to be the case in 2.4.x.. perhaps this
could be the source of the trouble.. not really sure how to fix it
though.
This makes me wonder if there is a bug in the scheduler. IIUC, a
realtime thread is *supposed* to have higher priority than any
non-SCHED_FIFO thread, regardless of "nice" value.
If we can nail down a case where this is definitely happening, someone
should report it to Andrew Morton.