23 Jun
2004
23 Jun
'04
3:22 p.m.
Florian Schmidt <mista.tapas(a)gmx.net> writes:
well, i stumbled across this thread on the
jackit-devel mailing list
about trying to set LD_ASSUME_KERNEL=2.4.22 and run all jack stuff
[server and clients with this env var set] and it worked
wonders.. 2*512 works very nice again..
Yes, this works fine for me. I can even run 2.6.7 with realtime-lsm
at 2*32 (using a delta-66). It gets quite a few xruns at that
setting, but will run all night without crashing. This is as good I
get with 2.4-lowlat.
Fernando has observed additional problems on Fedora Core 2, which are
not fixed by setting this environment variable. He developed a JACK
patch to hack around some additional bugs in pthread_create(). These
have not yet been integrated into JACK CVS, but should be soon.
Because of these problems, CCRMA currently does not recommend using
FC2.
i suspect this is nptl related (see the jackit-devel
thread for
details:
http://sourceforge.net/mailarchive/message.php?msg_id=8629219).. i
think the LD_ASSUME_KERNEL switch somehow makes ld.so link to another
libc or something w/o nptl? anyone knows details?
Similar problems have been observed with 2.6 kernels even without
NPTL. The environment variable seems to force use of the 2.4-style
kernel interfaces, instead.
so i just wanted to urge all the users of 2.6.x and
who experience
strange weird non rt operation with jack to try it. maybe it
helps...
i wrote myself a bash script called "realrealtime" and put that in my
path:
LD_ASSUME_KERNEL=2.4.22 $@
and use that to start al my jack stuff :)
That works.
Or, you can just set it globally in your ~/.profile (or wherever you
choose to put things like that).
Any ideas about why jackd behaves so weird in the
first place
appreciated..
I don't think anyone fully understands the problem, yet. It *seems*
to be somewhere in the interaction between the kernel and the pthreads
library.
--
joq