From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clark Williams Subject: Re: rt kernel, pro-audio use Date: Thu, 20 Dec 2012 11:00:52 -0600 Message-ID: <20121220110052.5f709692@redhat.com> References: <50D231F5.4060604@gentoostudio.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/QNXaxTJoD9HxDfvxg3aTFHw"; protocol="application/pgp-signature" Cc: linux-rt-users@vger.kernel.org To: Damien Moody Return-path: Received: from mx1.redhat.com ([209.132.183.28]:11359 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751367Ab2LTRBA (ORCPT ); Thu, 20 Dec 2012 12:01:00 -0500 In-Reply-To: <50D231F5.4060604@gentoostudio.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: --Sig_/QNXaxTJoD9HxDfvxg3aTFHw Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 19 Dec 2012 21:30:29 +0000 Damien Moody wrote: > Hi, >=20 > I have a couple of questions. >=20 > 1. I'd like to keep informed when the rt kernel gets updated, so I can=20 > put up a new Gentoo ebuild on my site (gentoostudio.org). Is this the=20 > list for that? If not, what is? >=20 > 2. I use the rt patches a la rt-sources on Gentoo. I'm a musician and=20 > audio engineer. What advantages does the rt patch set provide over other= =20 > patch sets like ck-sources and pf-sources, where latency can be=20 > configured to be very low? I'd like to document this on my site. > I use an RT-patched kernel with Fedora to record drum tracks with Ardour3+jack+ffado. I can record 16-channels of 24-bit samples at 48000Hz through a pair of Presonus FP10s attached to a Lenovo W510 laptop and I honestly can't remember the last time I had an xrun.=20 I'm sure plenty of people can do this with a standard kernel that's been tuned but no matter how much they tune it, there's always the possibility of running into a priority-inversion situation. The RT patchset converts most of the spinlocks in the kernel to an rt_mutext_t. The rt_mutex_t lock has a priority-inheritance chain that allows for a temporary priority boost of a thread holding a lock when a higher priority thread tries to claim the lock. This prevents intermediate priority threads from preventng the lock-holder thread from running, delaying the high priority thread indefinitely.=20 Clark --Sig_/QNXaxTJoD9HxDfvxg3aTFHw Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAlDTREQACgkQHyuj/+TTEp3cxgCfRlSAV5JzUd+dlFYSgIwwnzpG HxIAn0JnuF+rKmID8Q54Z+lWBIG9k8qG =xZRm -----END PGP SIGNATURE----- --Sig_/QNXaxTJoD9HxDfvxg3aTFHw--