From owner-freebsd-smp@FreeBSD.ORG Fri Feb 17 15:51:06 2006 Return-Path: X-Original-To: freebsd-smp@freebsd.org Delivered-To: freebsd-smp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0947716A420 for ; Fri, 17 Feb 2006 15:51:06 +0000 (GMT) (envelope-from elessar@bsdforen.de) Received: from postfix.bsdforen.de (bsdforen.de [212.204.60.79]) by mx1.FreeBSD.org (Postfix) with ESMTP id 71D8F43D45 for ; Fri, 17 Feb 2006 15:51:05 +0000 (GMT) (envelope-from elessar@bsdforen.de) Received: by postfix.bsdforen.de (Postfix, from userid 20000) id 9187F6844BA; Fri, 17 Feb 2006 16:51:04 +0100 (CET) Received: from localhost (postfix [127.0.0.3]) by postfix.bsdforen.de (Postfix) with ESMTP id A28C46844B7 for ; Fri, 17 Feb 2006 16:51:03 +0100 (CET) Received: from postfix.bsdforen.de ([127.0.0.3]) by localhost (postfix.bsdforen.de [127.0.0.3]) (amavisd-new, port 10024) with LMTP id 33106-04 for ; Fri, 17 Feb 2006 16:51:03 +0100 (CET) Received: from loki (p549CFDF8.dip.t-dialin.net [84.156.253.248]) by postfix.bsdforen.de (Postfix) with ESMTP id 557146844B6 for ; Fri, 17 Feb 2006 16:51:00 +0100 (CET) Date: Fri, 17 Feb 2006 16:50:39 +0100 From: Joerg Pernfuss To: freebsd-smp@freebsd.org Message-ID: <20060217165039.79879ad6@loki> In-Reply-To: <6845d25a0602170732p4b982120r9b0bec7431fa6029@mail.gmail.com> References: <6845d25a0602170732p4b982120r9b0bec7431fa6029@mail.gmail.com> X-Mailer: Sylpheed-Claws 1.9.100 (GTK+ 2.8.9; i386-portbld-freebsd6.0) Mime-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_vh_3HvhcZY1=sTjCj.SuuaF"; protocol="application/pgp-signature"; micalg=PGP-SHA1 X-Virus-Scanned: amavisd-new at bsdforen.de X-DSPAM-Result: Innocent X-DSPAM-Confidence: 0.9997 X-DSPAM-Probability: 0.0000 X-DSPAM-Signature: 43f5f0e8358406023667501 X-DSPAM-User: global Subject: Re: HT/SMP Question (FreeBSD 6.0) X-BeenThere: freebsd-smp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD SMP implementation group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2006 15:51:06 -0000 --Sig_vh_3HvhcZY1=sTjCj.SuuaF Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 17 Feb 2006 10:32:42 -0500 Dave Stephens wrote: > I've upgraded my web server's CPU to one with HT and I was curious > about the current state of affairs with HT compatibility and speed > under FreeBSD 6.0. I've followed the SMP lists for some time and > honestly I've lost track on whether it's a good thing to enable SMP in > my kernel or not and whether there are special options for HT in the > kernel config. >=20 > Sorry this is so vague, I'm not having a problem as I'm running my > custom kernel with HT/SMP disabled for now. In my searches the > consensus seems to be that if you don't have 2 real cores don't bother > with SMP and I want to confirm that is still the case. Any info > anyone can offer would be greatly appreciated! Thanks! The best advice I can give you is that I can't give you advice. Varous combinations of HT enabled/disabled and SCHED_4BSD/ULE give (in some cases very) different results on different hardware and different workloads. If you have the time, motivation and a suitable testcase you can check what works best for you. In the majority of cases this seems to be HT disabled/SCHED_4BSD though. Regards, Joerg --=20 | /"\ ASCII ribbon | GnuPG Key ID | e86d b753 3deb e749 6c3a | | \ / campaign against | 0xbbcaad24 | 5706 1f7d 6cfd bbca ad24 | | X HTML in email | Now featuring a brand new GPG-Key! | | / \ and news | Please update your keyring. | --Sig_vh_3HvhcZY1=sTjCj.SuuaF Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFD9fDYH31s/bvKrSQRAl0BAJwL+EGCx7f18Ef1fZy1LvszD/cFjwCeIJuc 6b4ssS9FSvq1d9kFkiFWgu4= =eMpc -----END PGP SIGNATURE----- --Sig_vh_3HvhcZY1=sTjCj.SuuaF--