Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264884AbTIDVAa (ORCPT ); Thu, 4 Sep 2003 17:00:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264908AbTIDVA3 (ORCPT ); Thu, 4 Sep 2003 17:00:29 -0400 Received: from mail.jlokier.co.uk ([81.29.64.88]:653 "EHLO mail.jlokier.co.uk") by vger.kernel.org with ESMTP id S264884AbTIDVA0 (ORCPT ); Thu, 4 Sep 2003 17:00:26 -0400 Date: Thu, 4 Sep 2003 22:00:07 +0100 From: Jamie Lokier To: Rusty Russell Cc: Hugh Dickins , Andrew Morton , Ingo Molnar , linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH] Alternate futex non-page-pinning and COW fix Message-ID: <20030904210007.GE31590@mail.jlokier.co.uk> References: <20030904014229.2EFBF2C097@lists.samba.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030904014229.2EFBF2C097@lists.samba.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1009 Lines: 22 Rusty Russell wrote: > I don't have a problem with the omission. mremap is logically > equivalent to munmap + mmap, so it's a subset of the "I unmapped > underneath my futex!". It's not like it's going to happen without the > caller knowing: if the address doesn't change, then the futexes won't > break. If they do, the caller needs to reset them anyway. I think mremap() on block of memory containing futexes is reasonable. Imagine a big data structure with a table futex locks at the start of it. I'm not sure how useful it is, but it's not worthless. Anyway, I have a patch, tested, which moves remapped futexes _and_ returns EFAULT to waiters when pages are unmapped. It's kept separate from the main futex patch so you can accept it or not. -- Jamie - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/