From owner-freebsd-arch Wed Oct 23 15:20: 9 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 414C137B401 for ; Wed, 23 Oct 2002 15:20:08 -0700 (PDT) Received: from beastie.mckusick.com (beastie.mckusick.com [209.31.233.184]) by mx1.FreeBSD.org (Postfix) with ESMTP id 23EB743E97 for ; Wed, 23 Oct 2002 15:20:07 -0700 (PDT) (envelope-from mckusick@beastie.mckusick.com) Received: from beastie.mckusick.com (localhost [127.0.0.1]) by beastie.mckusick.com (8.12.3/8.12.3) with ESMTP id g9NMJv59010962; Wed, 23 Oct 2002 15:19:58 -0700 (PDT) (envelope-from mckusick@beastie.mckusick.com) Message-Id: <200210232219.g9NMJv59010962@beastie.mckusick.com> To: Jeff Roberson Subject: Re: KVAless IO and buffer cache changes Cc: arch@FreeBSD.ORG In-Reply-To: Your message of "Wed, 23 Oct 2002 17:43:50 EDT." <20021023165651.W22147-100000@mail.chesapeake.net> Date: Wed, 23 Oct 2002 15:19:57 -0700 From: Kirk McKusick 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 Overall I am in agreement with your plan. The devil of course is in getting the details right. I would welcome seeing more of your design notes. The breakout of the I/O portion of current bufs into a struct bio was the first (necessary) step in moving in the direction that I think you are proposing. The struct bio holds the I/O request while all the identity and related filesystem state remains in the struct buf. Whether it is sensible to continue keeping all this state in struct buf, or splitting struct buf into two distinct objects is still an open question in my mind. In any event, it is important that state not get pushed into the struct bio which should remain purely as an I/O work request. Kirk McKusick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message