From owner-freebsd-emulation Thu Dec 30 17: 2:59 1999 Delivered-To: freebsd-emulation@freebsd.org Received: from overcee.netplex.com.au (overcee.netplex.com.au [202.12.86.7]) by hub.freebsd.org (Postfix) with ESMTP id 01D7B15301; Thu, 30 Dec 1999 17:02:48 -0800 (PST) (envelope-from peter@netplex.com.au) Received: from netplex.com.au (localhost [127.0.0.1]) by overcee.netplex.com.au (Postfix) with ESMTP id C630E1CA0; Fri, 31 Dec 1999 09:02:45 +0800 (WST) (envelope-from peter@netplex.com.au) X-Mailer: exmh version 2.1.1 10/15/1999 To: Guido van Rooij Cc: Hidetoshi Shimokawa , vsilyaev@mindspring.com, dillon@freebsd.org, freebsd-emulation@FreeBSD.ORG, dbutter@wireless.net Subject: Re: VMware: Questions... In-Reply-To: Message from Guido van Rooij of "Wed, 22 Dec 1999 22:48:03 +0100." <19991222224803.A410@gvr.gvr.org> Date: Fri, 31 Dec 1999 09:02:45 +0800 From: Peter Wemm Message-Id: <19991231010245.C630E1CA0@overcee.netplex.com.au> Sender: owner-freebsd-emulation@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Guido van Rooij wrote: > On Mon, Dec 20, 1999 at 11:31:49PM +0800, Peter Wemm wrote: > > > > > > This is because mmaped file is written every 30 second by sync daemon. > > > The file is usually named /var/tmp/ram0 but it's unlinked right after > > > opened so you cannot see it by 'ls' although it exits. > > > > It would be nice if the VFS/VM system detected this automatically and > > switched on NOSYNC for files that got unlinked... I wouldn't be suprised i f > > this is what Linux does. Matt, is this possible? > > > > I havent seen an answer to this question yet. If it is possible, that > would be very nice. I doubt it though, but my knowledge on that part > of the system is rather limited. > A quick workaround could be to look at the ref count of the underlying > inode of the fd passed to the linux mmap > If the refcount is one then clearly the inode is no being referenced through > a directory entry in the file system. This could even be done for the general > mmap call (provided a regular file of course). But it might be a very > specific situation because one usually would not used a file backed > mmap in FreeBSD, yet use an anonymous mmap. I had a go, it turned out to be quite easy (so far). I haven't finished verifying that it's doing everything exactly as expected yet though. Cheers, -Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-emulation" in the body of the message