From owner-freebsd-hackers Wed May 15 10: 6:42 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by hub.freebsd.org (Postfix) with ESMTP id 31B7437B403; Wed, 15 May 2002 10:06:37 -0700 (PDT) Received: by elvis.mu.org (Postfix, from userid 1192) id F0B5DAE216; Wed, 15 May 2002 10:06:36 -0700 (PDT) Date: Wed, 15 May 2002 10:06:36 -0700 From: Alfred Perlstein To: "Andrew R. Reiter" Cc: Terry Lambert , Richard Sharpe , freebsd-hackers@FreeBSD.org Subject: Re: File locking, closes and performance in a distributed filesystemenv Message-ID: <20020515170636.GI1585@elvis.mu.org> References: <20020515155101.GF1585@elvis.mu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.27i Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Andrew R. Reiter [020515 09:54] wrote: > On Wed, 15 May 2002, Alfred Perlstein wrote: > > :* Terry Lambert [020515 01:36] wrote: > :> Alfred Perlstein wrote: > :> > As Terry stated you can't do that, however you could cache that the > :> > VNODE has a lock, that would reduce the requirement for calling the > :> > ADVLOCK VOP. > :> You'd really have to know when the lock list went to NULL, to get > :> any benefit out of it, since locking would still end up being per-file > :> sticky. You could post-check after every successful unlock... but to > :> cache the remote state would mean another RPC to ask for locks, which > :> would just be front-loading the expense, instead of back-loading it. > : > :[snip] > : > :He could also maintain a local cache of this per vnode, basically > :maintain a mirror of the lock list locally in order to see if a remote > :op must be done. > > Isn't this sorta like coda? I'm not a coda expert so I wouldn't know, but I wasn't professing to have invented something profound by suggesting a client cache. :) -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' Tax deductible donations for FreeBSD: http://www.freebsdfoundation.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message