From owner-freebsd-fs Mon Jun 1 19:16:43 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA10919 for freebsd-fs-outgoing; Mon, 1 Jun 1998 19:16:43 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from parkplace.cet.co.jp (parkplace.cet.co.jp [202.32.64.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA10844 for ; Mon, 1 Jun 1998 19:15:16 -0700 (PDT) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by parkplace.cet.co.jp (8.8.8/CET-v2.2) with SMTP id CAA23673; Tue, 2 Jun 1998 02:13:53 GMT Date: Tue, 2 Jun 1998 11:13:53 +0900 (JST) From: Michael Hancock To: Cejka Rudolf cc: freebsd-fs@FreeBSD.ORG Subject: Re: VFSs in -current: Are they working? In-Reply-To: <199805281757.RAA20583@sts.dcse.fee.vutbr.cz> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Thu, 28 May 1998, Cejka Rudolf wrote: > > I'm reading news about -current since April and it seems to me that nobody > has problems with virtual filesystems. And what about null layer & kern/6465? > (Does anybody use null layer?) Or is this only my problem on my -current box? > Should I write more information about kern/6465? > > I'm sorry, but I don't know, where I may search this critical bug. > In VFS? Null layer looks too simple... > In VM space? Are there still VM bugs? I'm working on fixing layering violations which will improve things. The next problem which is more serious for is name/object coherence. Operations like mmap, read, write, getpages, and putpages can get incoherent because they will operate on different objects. One solution is to proxy everything down to the underlying object. One pie in the sky solution is to separate the notion of who is the cacher and who is the pager. Then get/putpages would accept a cachevp and a pagervp. You would then have to write a sophisticated cachemgr to orchestrate everything including data pages and other object attributes. If you want to find papers on these topics then search the net for things like filesystems, the spring project, and heidemann. Regards, Mike > Any suggestions? (Please...) > > Thanks. > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message