From owner-freebsd-current Sun Mar 1 07:52:07 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA27058 for freebsd-current-outgoing; Sun, 1 Mar 1998 07:52:07 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA27048 for ; Sun, 1 Mar 1998 07:52:04 -0800 (PST) (envelope-from toor@dyson.iquest.net) Received: (from root@localhost) by dyson.iquest.net (8.8.8/8.8.8) id KAA02547; Sun, 1 Mar 1998 10:51:46 -0500 (EST) (envelope-from toor) Message-Id: <199803011551.KAA02547@dyson.iquest.net> Subject: Re: VM: Process hangs sleeping on vmpfw In-Reply-To: <199803011032.NAA02269@tejblum.dnttm.rssi.ru> from Dmitrij Tejblum at "Mar 1, 98 01:32:57 pm" To: dima@tejblum.dnttm.rssi.ru (Dmitrij Tejblum) Date: Sun, 1 Mar 1998 10:51:46 -0500 (EST) Cc: tlambert@primenet.com, FreeBSD-current@FreeBSD.ORG From: "John S. Dyson" Reply-To: dyson@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL32 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Dmitrij Tejblum said: > > > > Unionfs. Specifically, the point is that the unionfs implementation > > should fan out to the correct underlying implementation. This means > > it shouldn't go into the default. > > But you must write correct getpages/putpages for unionfs in any case. > Or, better, make a bypass routine for unionfs, to avoid similar > problems with future new vnode operations :-). > Yes. FS types such as union and null where the files are exposed from multiple vantage points have severe coherency problems, and I will likely help take a look at those issues when this stuff all settles out. > > > Secondly, you can't make FS-specific optimizations. > > Nothing prevent a filesystem to implement its own getpages/putpages and > override the default. > Yes. The original scheme that we had implemented that, in a VM centric way (which was an expedient choice for me at the time.) The scheme was changed to look more VFS centric, and cannot say that is bad at all. I think that moving to a VFS centric approach is less "eccentric." :-). -- John | Never try to teach a pig to sing, dyson@freebsd.org | it just makes you look stupid, jdyson@nc.com | and it irritates the pig. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message