From owner-freebsd-smp Tue Dec 5 8:23: 9 2000 From owner-freebsd-smp@FreeBSD.ORG Tue Dec 5 08:23:08 2000 Return-Path: Delivered-To: freebsd-smp@freebsd.org Received: from berserker.bsdi.com (unknown [199.79.183.1]) by hub.freebsd.org (Postfix) with ESMTP id 1828937B400; Tue, 5 Dec 2000 08:23:07 -0800 (PST) Received: from berserker.bsdi.com (cp@localhost.bsdi.com [127.0.0.1]) by berserker.bsdi.com (8.11.1/8.9.3) with ESMTP id eB5GMtm00562; Tue, 5 Dec 2000 09:22:55 -0700 (MST) (envelope-from cp@berserker.bsdi.com) Message-Id: <200012051622.eB5GMtm00562@berserker.bsdi.com> To: Julian Elischer Cc: Mike Smith , brian@FreeBSD.org, archie@FreeBSD.org, phk@FreeBSD.org, smp@FreeBSD.org Subject: Re: Netgraph and SMP In-reply-to: Your message of "Mon, 04 Dec 2000 13:40:08 PST." <200012042140.eB4Le9F01294@mass.osd.bsdi.com> From: Chuck Paterson Date: Tue, 05 Dec 2000 09:22:55 -0700 Sender: cp@berserker.bsdi.com Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Julian, A standard lock manager lock will provide the functionality Mike talks about below. Chuck Mike Smith wrote on: Mon, 04 Dec 2000 13:40:08 PST } }The simplest structure for this is a shared/exclusive lock }that supports intention; Terry would have ranted about this. (He would }have called it a SIX-lock, I think). } }In this model, you acquire the lock in 'shared' mode every time you enter }Netgraph, and release it when you leave. } }When you plan to make changes to Netgraph, you get the lock in }'exclusive' mode. 'Intention' comes in here; now that you are trying to }get the lock in exclusive mode, your intention is recorded and nobody }else can get it in 'shared' mode, so eventually all the users drain out }of Netgraph and you get the lock. } }This may sound simplistic, but given that you don't necessarily make }changes to Netgraph very often, this is quite likely more than adequate }for now. } To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message