Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754028AbcDDHbH (ORCPT ); Mon, 4 Apr 2016 03:31:07 -0400 Received: from mail-lb0-f195.google.com ([209.85.217.195]:33220 "EHLO mail-lb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbcDDHbF (ORCPT ); Mon, 4 Apr 2016 03:31:05 -0400 Date: Mon, 4 Apr 2016 09:31:01 +0200 From: Michal Hocko To: Piotr Kwapulinski Cc: akpm@linux-foundation.org, mtk.manpages@gmail.com, cmetcalf@mellanox.com, arnd@arndb.de, viro@zeniv.linux.org.uk, mszeredi@suse.cz, dave@stgolabs.net, kirill.shutemov@linux.intel.com, vbabka@suse.cz, mingo@kernel.org, dan.j.williams@intel.com, dave.hansen@linux.intel.com, koct9i@gmail.com, hannes@cmpxchg.org, jack@suse.cz, xiexiuqi@huawei.com, iamjoonsoo.kim@lge.com, oleg@redhat.com, gang.chen.5i5j@gmail.com, aarcange@redhat.com, aryabinin@virtuozzo.com, rientjes@google.com, denc716@gmail.com, toshi.kani@hpe.com, ldufour@linux.vnet.ibm.com, kuleshovmail@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 0/3] mm/mmap.c: don't unmap the overlapping VMA(s) Message-ID: <20160404073100.GA10272@dhcp22.suse.cz> References: <1459624654-7955-1-git-send-email-kwapulinski.piotr@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459624654-7955-1-git-send-email-kwapulinski.piotr@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 405 Lines: 11 On Sat 02-04-16 21:17:31, Piotr Kwapulinski wrote: > Currently the mmap(MAP_FIXED) discards the overlapping part of the > existing VMA(s). > Introduce the new MAP_DONTUNMAP flag which forces the mmap to fail > with ENOMEM whenever the overlapping occurs and MAP_FIXED is set. > No existing mapping(s) is discarded. You forgot to tell us what is the use case for this new flag. -- Michal Hocko SUSE Labs