From owner-cvs-all Tue Sep 24 23: 4:34 2002 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0FD9037B401; Tue, 24 Sep 2002 23:04:33 -0700 (PDT) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4C7EE43E6A; Tue, 24 Sep 2002 23:04:32 -0700 (PDT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id g8P64G4v013690; Wed, 25 Sep 2002 08:04:17 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Jeff Roberson Cc: Robert Watson , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/sys lockmgr.h In-Reply-To: Your message of "Wed, 25 Sep 2002 00:50:29 EDT." <20020925003055.L97589-100000@mail.chesapeake.net> Date: Wed, 25 Sep 2002 08:04:16 +0200 Message-ID: <13689.1032933856@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <20020925003055.L97589-100000@mail.chesapeake.net>, Jeff Roberson wr ites: >I'd like to get rid of the redundant *_fsync code. These are probably all >copies of ufs from different points and are broken in many different ways. I agree. >In terms of SMP safing vfs, it looks like struct buf needs a mutex. I >figured out the lock order, it would be something like: > >vn lock >buf lock >vn interlock >buf interlock Beware of vinum. >Also, the namecache has to be locked down. This is nontrivial. An early >attempt to use a big global lock failed. The mount structure has not been >locked down. The vnode/device relationship needs some more looking. vnode/device locking can be done in specfs, there exists no other paths between them (I hope!) If I manage to make DEVFS mandatory, that will be devfs instead of specfs. >In short, there is still much to do. As I have said before, my goal is to >have at least the top layer of VFS out from underneath Giant by 5.0. Can't we also put a lock per mountpoint and pull the filesystems out that way ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message