From owner-freebsd-questions@FreeBSD.ORG Mon Oct 6 21:57:52 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 51A9A106568B for ; Mon, 6 Oct 2008 21:57:52 +0000 (UTC) (envelope-from rsmith@xs4all.nl) Received: from smtp-vbr5.xs4all.nl (smtp-vbr5.xs4all.nl [194.109.24.25]) by mx1.freebsd.org (Postfix) with ESMTP id C297F8FC12 for ; Mon, 6 Oct 2008 21:57:51 +0000 (UTC) (envelope-from rsmith@xs4all.nl) Received: from slackbox.xs4all.nl (slackbox.xs4all.nl [213.84.242.160]) by smtp-vbr5.xs4all.nl (8.13.8/8.13.8) with ESMTP id m96Lvntt061249; Mon, 6 Oct 2008 23:57:49 +0200 (CEST) (envelope-from rsmith@xs4all.nl) Received: by slackbox.xs4all.nl (Postfix, from userid 1001) id 1A5B2BA8A; Mon, 6 Oct 2008 23:57:49 +0200 (CEST) Date: Mon, 6 Oct 2008 23:57:49 +0200 From: Roland Smith To: Wojciech Puchar Message-ID: <20081006215749.GA68933@slackbox.xs4all.nl> References: <20081006221523.P3921@wojtek.tensor.gdynia.pl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="82I3+IH0IqGh5yIs" Content-Disposition: inline In-Reply-To: <20081006221523.P3921@wojtek.tensor.gdynia.pl> X-GPG-Fingerprint: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 X-GPG-Key: http://www.xs4all.nl/~rsmith/pubkey.txt X-GPG-Notice: If this message is not signed, don't assume I sent it! User-Agent: Mutt/1.5.18 (2008-05-17) X-Virus-Scanned: by XS4ALL Virus Scanner Cc: freebsd-questions@freebsd.org Subject: Re: TRUE realtime priority X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Oct 2008 21:57:52 -0000 --82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 06, 2008 at 10:21:01PM +0200, Wojciech Puchar wrote: > is it possible on FreeBSD No, I think. =20 > i run asterisk with realtime priority. it works perfectly no matter how= =20 > much CPU is loaded by other non-telephony tasks. >=20 > but with lots of VM pressure it starts to so... like like tha..that... >=20 > what causes it to behave like that and how to fix it. Well, basically you are the only one who can answer that. And that's not a paradox or an attempt at humor. You should investigate. Maybe interrupts aren't processed fast enough (hardware sharing an interrupt?), or memory or kernel resources are low. > for example when lots of spam comes to server and lots of resource hungry= =20 > spamassassin processes are spawned our calls starts to be crappy. >=20 > CPU load for asterisk rarely exceed few percent! Yes, but FreeBSD isn't a _hard_ real-time OS (see below). =20 > i think having separate computer just for this is stupid, i would do this= =20 > having no other choice, but can it be done without this. >=20 > realtime priority is realtime priority anyway - it should work. It does depend what you mean by real-time. Usually real-time systems are devided into the "soft" and "hard" categories. See the Wikipedia article on real-time computing [http://en.wikipedia.org/wiki/Real-time_computing] and operating systems [http://en.wikipedia.org/wiki/Real-time_operating_sys= tem]. Most hard real-time systems are embedded systems with a specific function (say, ECU, FADEC, ABS, digital music player). I don't think there are general use OS's which would classify as hard real-time (AFAIK, RTLinux runs Linux as a low-priority task on a real-time core). Most of them support soft real-time, as in "we'll try to get these tasks done before a specific deadline, but no promises." Roland --=20 R.F.Smith http://www.xs4all.nl/~rsmith/ [plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated] pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725) --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkjqid0ACgkQEnfvsMMhpyXbjwCfTw5/vWdfma2Bm+inj73KFI2L iDoAoKvBm9bRpj+OdHLatDCH9RvFniMF =m6/E -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs--