From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1EMCOk-0001sP-3P for user-mode-linux-devel@lists.sourceforge.net; Sun, 02 Oct 2005 15:33:34 -0700 Received: from lakshmi.addtoit.com ([198.99.130.6] helo=lakshmi.solana.com) by mail.sourceforge.net with esmtp (Exim 4.44) id 1ELtXx-0005uD-Rr for user-mode-linux-devel@lists.sourceforge.net; Sat, 01 Oct 2005 19:25:52 -0700 From: Jeff Dike Subject: Re: [uml-devel] a question about sigsetjmp() in copy_from/to_user() Message-ID: <20051002010315.GA4778@localhost.localdomain> References: <3524bf1f050927070645b999bd@mail.gmail.com> <20050928145009.GA11610@ccure.user-mode-linux.org> <3524bf1f0509281225180173ae@mail.gmail.com> <200509291409.28067.blaisorblade@yahoo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200509291409.28067.blaisorblade@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sat, 1 Oct 2005 21:03:15 -0400 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net, Young Koh On Thu, Sep 29, 2005 at 02:09:27PM +0200, Blaisorblade wrote: > Again, that page is not bad. There is no page yet for this address, and the > host won't allocate one for now. It is bad in the sense that, unless some space is freed on that mount, a reference to the page will always fault. > Ok, this makes a bit of sense, even if IMHO it doesn't work, I now see your > point (but I still insist with what said above). Explain why it doesn't work. > However, even a dirtied page could be "bad", if it has been swapped. If > we're getting a SIGBUS, it meant that it didn't succeed in freeing any > memory. No it can't. A swapped page still counts as occupying space in the filesystem. If a page was successfully allocated, then accesses to it will always succeed, even if it needs to be swapped in. > And, frankly, unless the UML ram file is kept on ramfs (which is RAM-only), > it can be swapped (both for disk-based filesystem and for tmpfs). > So, I don't think what you suggest could work. Swapping makes no difference. Jeff ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel