From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754226AbYL3IsK (ORCPT ); Tue, 30 Dec 2008 03:48:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751497AbYL3Ir4 (ORCPT ); Tue, 30 Dec 2008 03:47:56 -0500 Received: from rv-out-0506.google.com ([209.85.198.229]:9469 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753919AbYL3Iry (ORCPT ); Tue, 30 Dec 2008 03:47:54 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=rEIoRtrR+MVzHnXuEaTMUHv3d2G0pk4zOfFTIWxij6VlzjrGKAjtcOkGy0Jr2MU+Yd FSzwSjdCYnYUv38acb+PzmUhqu91Bc9o1+36Tb4ab8vr9LHyXBCg33uxn0f8k/E1hevB vqGLvtZJQXWo4whGuBaEXK8NqrKSXZjlNcL+k= Message-ID: <8bd0f97a0812300047n32c81957u60b3d83c41422486@mail.gmail.com> Date: Tue, 30 Dec 2008 03:47:53 -0500 From: "Mike Frysinger" To: "Andrew Morton" Subject: Re: [GIT] NOMMU mmap changes Cc: "David Howells" , torvalds@linux-foundation.org, rgetz@blackfin.uclinux.org, lethal@linux-sh.org, bernds_cb1@t-online.de, linux-kernel@vger.kernel.org In-Reply-To: <20081230004246.4aa62478.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <21562.1230572526@redhat.com> <20081230004246.4aa62478.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 30, 2008 at 03:42, Andrew Morton wrote: > On Mon, 29 Dec 2008 17:42:06 +0000 David Howells wrote: >> Can you pull the attached request please? It makes the following changes: >> >> (1) Discard the askedalloc and realalloc variables from NOMMU mmap as nothing >> uses the values computed. >> >> (2) Stop ELF-FDPIC and FLAT binary formats from using kobjsize() by stopping >> them from attempting to expand the stack segments to use the full amount >> allocated (we'd like to get rid of kobjsize()). >> >> (3) Support XIP on initramfs. This is simply a matter of using truncate() to >> pre-size the files ramfs files so generated so that they are constructed >> from contiguous pages, and so can be mapped in place with NOMMU mmap(). >> >> (4) Make NOMMU VMAs per-MM as for MMU-mode Linux. Whilst this uses more >> memory, it also fixes a couple of bugs: >> >> (*) The SYSV SHM nattch count for a segment must reflect the number of >> attachments made, but since attachments were being shared, it did >> not. >> >> (*) The VMA's vm_mm is set to point to the parent mm by an exec'ing >> process when VM_EXECUTABLE is specified, but vm_mm was being shared >> by all the processes that shared that VMA. >> >> (5) NOMMU private non-shared mmaps are allocated with alloc_pages() rather >> than kmalloc(), and without using __GFP_COMP. This makes handling of >> the pages in an mmap() region simpler. Excess space can be trimmed after >> allocation (configurable in /proc/sys). >> >> (6) A new struct (vm_region) is introduced to track mapped regions in NOMMU >> mode, and to handle the sharing of backing stores. This required the >> vm_region structs of PowerPC and ARM to be renamed (the former patch has >> been pulled via the ppc tree). >> >> (7) NOMMU VMAs are attached to their parent inodes as for MMU VMAs. >> >> (8) munmap() may do a partial unmapping. >> >> (9) Core dumping for ELF-FDPIC is simplified as the NOMMU- and MMU-mode code >> behaves more similarly. >> >> (10) /proc/maps provided in NOMMU mode now shows the regions allocated rather >> than the common VMA list. /proc/meminfo now shows the amount of RAM >> currently allocated to private copies by private mmaps. >> >> These patches have had some soak time in linux-next. I've also applied them >> as-are to the latest merge window and tested that on my FRV board. >> >> David >> --- >> The following changes since commit 1bda71282ded6a2e09a2db7c8884542fb46bfd4f: >> Linus Torvalds (1): >> Merge branch 'for-linus' of git://git.kernel.org/.../ieee1394/linux1394-2.6 >> >> are available in the git repository at: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu.git master >> >> David Howells (8): >> NOMMU: Rename PowerPC's struct vm_region >> NOMMU: Rename ARM's struct vm_region >> NOMMU: Delete askedalloc and realalloc variables >> NOMMU: Make VMAs per MM as for MMU-mode linux >> NOMMU: Improve procfs output using per-MM VMAs >> FDPIC: Don't attempt to expand the userspace stack to fill the space allocated >> FLAT: Don't attempt to expand the userspace stack to fill the space allocated >> NOMMU: Support XIP on initramfs >> >> Matt Mackall (1): >> shmem: remove unused shmem_get_unmapped_area >> >> Paul Mundt (2): >> NOMMU: Make mmap allocation page trimming behaviour configurable. >> NOMMU: Teach kobjsize() about VMA regions. > > hm, has this all been suitably reviewed/publicised? it has been among the people who actually use nommu (frv/sh/blackfin). i think we've been ragging on David for not getting this stuff in two releases ago ;). -mike