From owner-freebsd-hackers Wed Apr 19 11:21:46 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from bingnet2.cc.binghamton.edu (bingnet2.cc.binghamton.edu [128.226.1.18]) by hub.freebsd.org (Postfix) with ESMTP id 13E9D37B531 for ; Wed, 19 Apr 2000 11:21:39 -0700 (PDT) (envelope-from zzhang@cs.binghamton.edu) Received: from sol.cs.binghamton.edu (sol.cs.binghamton.edu [128.226.123.100]) by bingnet2.cc.binghamton.edu (8.9.3/8.9.3) with ESMTP id OAA11241; Wed, 19 Apr 2000 14:21:32 -0400 (EDT) Date: Wed, 19 Apr 2000 14:21:29 -0400 (EDT) From: Zhihui Zhang To: Matthew Dillon Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Questions of the syncer process In-Reply-To: <200004191709.KAA23683@apollo.backplane.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 19 Apr 2000, Matthew Dillon wrote: > : > :I have two questions related to the syncer process that replaces the old > :update process: > : > :(1) The syncer process is waken up once a second (it sleeps on lbolt). If > :I have more than 30 mounted filesystems, then each filesystem's dirty data > :will stay more than 30 seconds. If I only have a couple of filesystems, > :then the syncer will run more frequenty than the old update process. Is > :this a good choice? > > The filesystem sync time has nothing to do with the number of > mounted filesystems. Every dirty vnode is added to the syncer > list and placed in a specific delay slot. The syncer gets to > it in that amount of time no matter how many mounted filesystems > there are - usually every 30 seconds or so. Thanks for your response. I reread the code and find out individual dirty vnodes can be put on the worklist. But why do we put the syncer vnodes on the worklist as well? It seems to me that they are there to make sure that each entire filesystem is sync'ed once in while. Since individual dirty vnodes have already been sync'ed, I do not know why it is necessary. -Zhihui To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message