Hi everyone I've recently moved a system over to Slackware 10.2 which utilises NPTL and I'm aware of the issues NPTL has raised in the past. Based on a comment on the Jack website though I sort of assumed that things were now in hand and that Jack had a workaround in place for the issue. Despite this I have found that jackd itself (when run using set_rtlimits) gives an error (-11, EAGAIN) when "creating realtime thread". I have already confirmed that set_rtlimits does operate correctly in the NPTL environment; it appears that for some reason pthread_create flatly refuses to create the RT thread even though the appropriate priority limits are set for the process. The LD_ASSUME_KERNEL hack does make jackd work; however, it would be nice to know what's going on (or whether in fact the problems are still being worked on). Are there any ideas? Interestingly enough, jack applications (ardour for example) do NOT need the LD_ASSUME_KERNEL hack - they start and operate fine without out. Only jack itself appears to have issues. Glibc is 2.3.5, getconf reports "NPTL 2.3.5" and kernel is 2.6.14 plus 2.6.14-rt13. 2.6.14-rc3-rt4 has the same issues. Oddly enough, it appears that under 2.6.13 things work fine even for jackd, but I need to confirm that tonight. Jack command line (from memory): jackd -R -d alsa -d hw:0 -n 4 -p 512 Jackd compiled against 2.6.14 headers with gcc 3.3.6. Kernel compiled with 3.3.6 also. Regards jonathan