From owner-freebsd-arch Thu Jun 20 3:35:10 2002 Delivered-To: freebsd-arch@freebsd.org Received: from rina.r.dl.itc.u-tokyo.ac.jp (rina.r.dl.itc.u-tokyo.ac.jp [133.11.199.247]) by hub.freebsd.org (Postfix) with ESMTP id A08B737B405 for ; Thu, 20 Jun 2002 03:35:07 -0700 (PDT) Received: from rina.r.dl.itc.u-tokyo.ac.jp (localhost [127.0.0.1]) by rina.r.dl.itc.u-tokyo.ac.jp (8.12.3+3.5Wbeta/3.7W-rina.r-Nankai-Koya) with ESMTP id g5KAZ53i029301 ; Thu, 20 Jun 2002 19:35:06 +0900 (JST) Message-Id: <200206201035.g5KAZ53i029301@rina.r.dl.itc.u-tokyo.ac.jp> Date: Thu, 20 Jun 2002 19:35:05 +0900 From: Seigo Tanimura To: arch@FreeBSD.org Subject: multiple threads for interrupts Cc: Seigo Tanimura User-Agent: Wanderlust/2.8.1 (Something) SEMI/1.14.3 (Ushinoya) FLIM/1.14.3 (=?ISO-8859-1?Q?Unebigory=F2mae?=) APEL/10.3 MULE XEmacs/21.1 (patch 14) (Cuyahoga Valley) (i386--freebsd) Organization: Digital Library Research Division, Information Techinology Centre, The University of Tokyo MIME-Version: 1.0 (generated by SEMI 1.14.3 - "Ushinoya") Content-Type: text/plain; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG At the moment, each interrupt type (hardware and swi) has only one kernel thread to handle interrupts. This can be a potential bottleneck in an SMP host because virtually only up to one processor can handle interrupts. One solution is to run multiple threads for each of the interrupt types. Since I noticed this issue first during my work of network locking, I have been tweaking the swi subsystem so that it runs multiple threads for an swi type. For those who are interested, the patch can be found at: http://people.FreeBSD.org/~tanimura/patches/swipool.diff.gz While I worked on only swis, hardware interrupts should suffer from the same issue as well. Thus it would be better to tweak the general interrupt mechanism rather than only the swi subsystem. I will see how that works in the next few days. Comments and flames are welcome. Thanks a lot. -- Seigo Tanimura To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message