From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f173.google.com (mail-ie0-f173.google.com [209.85.223.173]) by kanga.kvack.org (Postfix) with ESMTP id 740CE6B0069 for ; Tue, 30 Sep 2014 22:32:37 -0400 (EDT) Received: by mail-ie0-f173.google.com with SMTP id tp5so187505ieb.18 for ; Tue, 30 Sep 2014 19:32:37 -0700 (PDT) Received: from mail-ie0-x236.google.com (mail-ie0-x236.google.com [2607:f8b0:4001:c03::236]) by mx.google.com with ESMTPS id u1si520042icw.52.2014.09.30.19.32.36 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 30 Sep 2014 19:32:36 -0700 (PDT) Received: by mail-ie0-f182.google.com with SMTP id rp18so175623iec.13 for ; Tue, 30 Sep 2014 19:32:36 -0700 (PDT) Message-ID: <542B67C1.9080303@gmail.com> Date: Tue, 30 Sep 2014 22:32:33 -0400 From: Daniel Micay MIME-Version: 1.0 Subject: Re: [PATCH v3] mm: add mremap flag for preserving the old mapping References: <1412052900-1722-1-git-send-email-danielmicay@gmail.com> <542A79AF.8060602@gmail.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Andrew Morton , Jason Evans , Linux API On 30/09/14 01:49 PM, Andy Lutomirski wrote: > > I think it might pay to add an explicit vm_op to authorize > duplication, especially for non-cow mappings. IOW this kind of > extension seems quite magical for anything that doesn't have the > normal COW semantics, including for plain old read-only mappings. This sounds like the best way forwards. Setting up the op for private, anonymous mappings and having it check vm_flags & VM_WRITE dynamically seems like it would be enough for the intended use case in general purpose allocators. It can be extended to other mapping types later if there's a compelling use case. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org