From owner-freebsd-current Tue Mar 2 15:17:33 1999 Delivered-To: freebsd-current@freebsd.org Received: from janus.syracuse.net (janus.syracuse.net [205.232.47.15]) by hub.freebsd.org (Postfix) with ESMTP id 92EE81507B for ; Tue, 2 Mar 1999 15:17:25 -0800 (PST) (envelope-from green@unixhelp.org) Received: from localhost (green@localhost) by janus.syracuse.net (8.8.8/8.8.7) with ESMTP id SAA09424; Tue, 2 Mar 1999 18:16:50 -0500 (EST) Date: Tue, 2 Mar 1999 18:16:50 -0500 (EST) From: Brian Feldman X-Sender: green@janus.syracuse.net To: Alan Cox Cc: Bruce Evans , current@FreeBSD.ORG Subject: Re: lockmgr panic with mmap() In-Reply-To: <19990302113704.B90473@nonpc.cs.rice.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 2 Mar 1999, Alan Cox wrote: > On Tue, Mar 02, 1999 at 10:41:46PM +1100, Bruce Evans wrote: > > > > Doesn't it modify the map indirectly vi subyte()? I think it wants > > to prevent modifications, but this is impossible. > > > > Bear with me, I'll have to split some hairs... > > We're only interested in whether mincore directly changes the vm_map, > literally modifying a vm_map_entry, etc. subyte is writing to memory, > not a vm_map_entry. subyte is only indirectly changing the map > because a page fault occurs. That page fault *is* (frequently) changing > the map, and we're deadlocking when it attempts to acquire the write lock > on the map. > > Basically, what I believe that you suggested yesterday, that mincore > release the lock around the subyte is correct. Code will > appear shortly... Where exactly does thrd_sleep come in, since that's where the program locks up now? Can't be killed, of course... > > Alan > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message > Brian Feldman _ __ ___ ___ ___ green@unixhelp.org _ __ ___ | _ ) __| \ http://www.freebsd.org/ _ __ ___ ____ | _ \__ \ |) | FreeBSD: The Power to Serve! _ __ ___ ____ _____ |___/___/___/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message