From owner-freebsd-current Sun Aug 29 23:52:15 1999 Delivered-To: freebsd-current@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id E5835152B5 for ; Sun, 29 Aug 1999 23:52:09 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id XAA10557; Sun, 29 Aug 1999 23:51:49 -0700 (PDT) (envelope-from dillon) Date: Sun, 29 Aug 1999 23:51:49 -0700 (PDT) From: Matthew Dillon Message-Id: <199908300651.XAA10557@apollo.backplane.com> To: Greg Lehey Cc: Bernd Walter , Mike Smith , Parag Patel , freebsd-current@FreeBSD.ORG Subject: Re: 4.0-CURRENT SMP crash with vinum raid-5 and softupdates References: <199908292224.PAA15435@dingo.cdrom.com> <199908292348.QAA07774@apollo.backplane.com> <19990830075311.A30271@cicely8.cicely.de> <199908300559.WAA09987@apollo.backplane.com> <19990830160155.G13904@freebie.lemis.com> <199908300636.XAA10399@apollo.backplane.com> <19990830161633.J13904@freebie.lemis.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :>> :>> What's a pbuf? :> :> Sorry, it isn't a pbuf. : :OK. But what is a pbuf? I've never heard that term before. A pbuf is a 'physical buffer'. Specifically, it is a struct buf structure used by low level device drivers to issue their own I/O. pbuf's are used by a number of modules. For example, they are used by the VFS clustering code to create a 'super buffer' that encompasses a number of smaller filesystem buffers. They are also used by the swapper to initiate low level disk I/O, and the VN device for same. :> That could cause long term problems but is neither here nor :> there at the moment, we'll deal with it later. : :I discussed it with Kirk, who wasn't too concerned. Do you have other :issues? : :Greg Naw, when we finally fix the struct buf's we'll deal with everything that uses them. As long as you do not special case structural fields (use them in a manner for which they were not designed), there shouldn't be any problem. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message