Chaskido de jack y alsa

Hola, si abro el qtractor con jack y jack esta utlizando el alsa, se me oye un chascido y en la sesion se messages aparece esto:


**** alsa_pcm: xrun of at least 9.241 msecs
19:50:36.244 XRUN callback (1 skipped).
**** alsa_pcm: xrun of at least 38.935 msecs
19:50:44.473 XRUN callback (281).
**** alsa_pcm: xrun of at least 0.861 msecs
**** alsa_pcm: xrun of at least 8.712 msecs
**** alsa_pcm: xrun of at least 46.336 msecs
19:50:46.210 XRUN callback (284).
19:50:46.590 XRUN callback (2 skipped).
**** alsa_pcm: xrun of at least 11.969 msecs
19:50:47.240 XRUN callback (285).
**** alsa_pcm: xrun of at least 8.908 msecs
19:50:48.636 XRUN callback (1 skipped).
**** alsa_pcm: xrun of at least 10.575 msecs
19:50:50.214 XRUN callback (287).
**** alsa_pcm: xrun of at least 9.286 msecs
19:50:51.241 XRUN callback (288).
**** alsa_pcm: xrun of at least 9.288 msecs
19:50:53.220 XRUN callback (289).
**** alsa_pcm: xrun of at least 47.443 msecs
19:50:54.230 XRUN callback (290).
**** alsa_pcm: xrun of at least 92.709 msecs
**** alsa_pcm: xrun of at least 13.665 msecs
19:50:54.822 XRUN callback (3 skipped).
**** alsa_pcm: xrun of at least 38.748 msecs
**** alsa_pcm: xrun of at least 42.561 msecs
**** alsa_pcm: xrun of at least 29.601 msecs
**** alsa_pcm: xrun of at least 43.081 msecs
19:50:56.866 XRUN callback (3 skipped).
**** alsa_pcm: xrun of at least 10.247 msecs
19:51:04.217 XRUN callback (297).
19:51:05.281 XRUN callback (298).
**** alsa_pcm: xrun of at least 5.983 msecs
19:51:09.216 XRUN callback (299).
**** alsa_pcm: xrun of at least 39.861 msecs
**** alsa_pcm: xrun of at least 0.125 msecs
19:51:10.497 XRUN callback (300).
**** alsa_pcm: xrun of at least 27.358 msecs


Alguien tiene idea de que puede ser?

Posiblemente de momento no estás corriendo jackd en modo realtime...