From owner-freebsd-hackers Tue Apr 20 14: 2:24 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id AFF1E1582F for ; Tue, 20 Apr 1999 14:02:20 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id NAA00957; Tue, 20 Apr 1999 13:59:47 -0700 (PDT) (envelope-from dillon) Date: Tue, 20 Apr 1999 13:59:47 -0700 (PDT) From: Matthew Dillon Message-Id: <199904202059.NAA00957@apollo.backplane.com> To: David Greenman Cc: John Dyson , hackers@FreeBSD.ORG Subject: Re: Directories not VMIO cached at all! References: <199904202056.NAA11478@implode.root.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG : :> All right. Then what about this.... right now vm_page_t's are :> required to be PAGE_SIZE'd. :> :> We change this. We allow vm_page_t's to be sized in multiples of :> DEV_BSIZE from 0 through to PAGE_SIZE, but not crossing a physical :> page boundry. We get rid of vm_page_t->valid and vm_page_t->dirty and :> turn those into PG_VALID and PG_DIRTY flags. we add vm_page_t->size. : : I prefer the current architecture, actually. Several problems come to :mind with your proposed scheme: On for example is problems with handling :filesystems with block sizes less than a page. I think there are a lot of :other problems, too, but I'm too busy to go looking for them. I don't :really see how it fixes anything, either - the wastage for directory blocks :will still be there unless you create fictitious pages and/or support offsets :within a page (in which case you likely will have page aliasing problems :to deal with). Yuck. : :-DG Oof. read the proposal more carefully ... I *AM* creating ficticious pages. Basically we are removing the functionality from the buffer cache and putting it in the VM cache directly. -Matt Matthew Dillon :David Greenman :Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org :Creator of high-performance Internet servers - http://www.terasolutions.com : To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message