From owner-freebsd-smp@FreeBSD.ORG Mon Nov 17 13:18:02 2008 Return-Path: Delivered-To: freebsd-smp@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 48EDA1065673 for ; Mon, 17 Nov 2008 13:18:02 +0000 (UTC) (envelope-from freebsd-smp@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id C394F8FC1A for ; Mon, 17 Nov 2008 13:18:01 +0000 (UTC) (envelope-from freebsd-smp@m.gmane.org) Received: from list by ciao.gmane.org with local (Exim 4.43) id 1L23zK-0005Rg-CP for freebsd-smp@freebsd.org; Mon, 17 Nov 2008 13:17:58 +0000 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Nov 2008 13:17:58 +0000 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Nov 2008 13:17:58 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-smp@freebsd.org From: Ivan Voras Date: Mon, 17 Nov 2008 14:18:36 +0100 Lines: 43 Message-ID: References: <42e3d810811100033w172e90dbl209ecbab640cc24f@mail.gmail.com> <200811111216.37462.jhb@freebsd.org> <42e3d810811130355x3857bceap447e134b18eee04b@mail.gmail.com> <200811131128.55220.jhb@freebsd.org> <42e3d810811170311uddc77daj176bc285722a0c8@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig72EB5AC1004F9F67F4407EC7" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.17 (X11/20080925) In-Reply-To: <42e3d810811170311uddc77daj176bc285722a0c8@mail.gmail.com> X-Enigmail-Version: 0.95.0 Sender: news Subject: Re: CPU affinity with ULE scheduler 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: Mon, 17 Nov 2008 13:18:02 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig72EB5AC1004F9F67F4407EC7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Archimedes Gaviola wrote: > With net.isr.direct=3D0, my IBM system lessens CPU utilization per > interface (bce0 and bce1) but swi1:net increase its utilization. > Can you explained what's happening here? What does net.isr.direct do > with the decrease of CPU utilization on its interface?=20 The system has a choice between processing the packets in the interrupt handler (the "irq:bce" process) or in a dedicated network process (the "swi:net" process). This is about protocol handling not simply receiving packets. With net.isr.direct you're toggling between those two options. If "direct" is 1, the packets are processed in the interrupt handler; if it's 0, the processing is delegated to swi. It's set to 1 by default because this setting should yield best latency. In both cases the code path a packet must go through is very similar: it has to be received, then processed through firewalls and network stack code, then delivered to application(s), so it's a serial process. There are things that could be better parallelized in the stack and people are working on them, but they will not be finished any time soon. --------------enig72EB5AC1004F9F67F4407EC7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFJIW8sldnAQVacBcgRAnPQAKC+5qlyAtI+mTT5eFP4te2BX8EWXgCg+REw Ff9Lv7GNlBhrtGNsp9Ojkss= =0AJK -----END PGP SIGNATURE----- --------------enig72EB5AC1004F9F67F4407EC7--