Florian Schmidt <mista.tapas@xxxxxxx> 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
