From owner-freebsd-hackers Fri Oct 8 14:35:51 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from mail-out2.apple.com (mail-out2.apple.com [17.254.0.51]) by hub.freebsd.org (Postfix) with ESMTP id 6B6DB15900 for ; Fri, 8 Oct 1999 14:35:42 -0700 (PDT) (envelope-from conrad@apple.com) Received: from mailgate2.apple.com ([17.129.100.225]) by mail-out2.apple.com (8.9.3/8.9.3) with ESMTP id OAA26917 for ; Fri, 8 Oct 1999 14:34:57 -0700 (PDT) Received: from scv1.apple.com (scv1.apple.com) by mailgate2.apple.com (Content Technologies SMTPRS 2.0.15) with ESMTP id ; Fri, 08 Oct 1999 14:35:40 -0700 Received: from [17.202.43.185] (wa.apple.com [17.202.43.185]) by scv1.apple.com (8.9.3/8.9.3) with ESMTP id OAA15457; Fri, 8 Oct 1999 14:35:39 -0700 (PDT) X-Sender: conrad@mail.apple.com Message-Id: In-Reply-To: <199910081859.LAA04227@apollo.backplane.com> References: MIME-Version: 1.0 Date: Fri, 8 Oct 1999 14:35:24 -0700 To: Matthew Dillon From: Conrad Minshall Subject: Re: read/write atomic? Cc: hackers@freebsd.org Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > It would be great if someone could ram such a change through the standards > committees. The changes nowadays are coming via "The Austin Group". See http://www.opengroup.org/austin/ and associated mailing list. >Alternatively Linux could become enough of a defacto standard > that we could ignore the standards committee. Barring that, the only > solution available to us to increase performance is to implement temporary > byte-ranged locks within the kernel to allow the I/O to be parallelized. > It isn't necessarily as bad as you think... support for such locks > already exists in order to deal with POSIX locks, but it would certainly > be easier if we didn't have to mess with it at all. Adding more reliance on the POSIX locks works fine if that implementation is extended to include the common filesystems... in particular NFS file locking seems needed. A footnote is ensuring the deadlock detection code finds deadlocks which span multiple filesystem types. BTW the NFS version 4 protocol includes byte range locking. Version 2 and 3 use a seperate (out-of-band) locking protocol. > Matthew Dillon > -- Conrad Minshall ... conrad@apple.com ... 408 974-2749 Apple Computer ... Mac OS X Core Operating Systems ... NFS/UDF/etc Alternative email address: rad@acm.org. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message