Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261292AbTIBVXa (ORCPT ); Tue, 2 Sep 2003 17:23:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261304AbTIBVXC (ORCPT ); Tue, 2 Sep 2003 17:23:02 -0400 Received: from mail.jlokier.co.uk ([81.29.64.88]:55434 "EHLO mail.jlokier.co.uk") by vger.kernel.org with ESMTP id S261292AbTIBVWz (ORCPT ); Tue, 2 Sep 2003 17:22:55 -0400 Date: Tue, 2 Sep 2003 22:20:56 +0100 From: Jamie Lokier To: Andrew Morton Cc: hugh@veritas.com, rusty@rustcorp.com.au, mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] Futex non-page-pinning fix Message-ID: <20030902212056.GA16805@mail.jlokier.co.uk> References: <20030902065144.GC7619@mail.jlokier.co.uk> <20030902195427.GA15262@mail.jlokier.co.uk> <20030902131537.53d02113.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030902131537.53d02113.akpm@osdl.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 867 Lines: 25 Andrew Morton wrote: > Jamie Lokier wrote: > > > > 3. For (vma & VM_SHARED), look up futex_qs keyed on > > (vma->vm_file, vma->vm_pgoff + (uaddr - vma->vm_start) >> > > PAGE_SHIFT, offset). > > That's a bit meaningless in non-linear mappings. You think it's worth supporting futexes on non-linear mappings? I see your point of view; they could be useful. In that case, the (vma & VM_SHARED) case needs to look up the correct pgoff or page after all. It might be worth a VM_NONLINEAR flag, to skip walking the page table in the non-linear case, but that's just an optimisation. -- 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/