On Tue, Jan 27, 2015 at 06:16:57PM +0200, Kirill A. Shutemov wrote: > On Mon, Jan 26, 2015 at 06:03:57AM -0800, Guenter Roeck wrote: > > On 01/26/2015 04:29 AM, Kirill A. Shutemov wrote: > > >On Fri, Jan 23, 2015 at 09:52:07PM -0800, Guenter Roeck wrote: > > >>On Fri, Jan 23, 2015 at 01:55:19PM -0800, Andrew Morton wrote: > > >>>On Fri, 23 Jan 2015 07:07:56 -0800 Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > >>> > > >>>>>> > > >>>>>>qemu:microblaze generates warnings to the console. > > >>>>>> > > >>>>>>WARNING: CPU: 0 PID: 32 at mm/mmap.c:2858 exit_mmap+0x184/0x1a4() > > >>>>>> > > >>>>>>with various call stacks. See > > >>>>>>http://server.roeck-us.net:8010/builders/qemu-microblaze-mmotm/builds/15/steps/qemubuildcommand/logs/stdio > > >>>>>>for details. > > >>>>> > > >>>>>Could you try patch below? Completely untested. > > >>>>> > > >>>>>>From b584bb8d493794f67484c0b57c161d61c02599bc Mon Sep 17 00:00:00 2001 > > >>>>>From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > > >>>>>Date: Fri, 23 Jan 2015 13:08:26 +0200 > > >>>>>Subject: [PATCH] microblaze: define __PAGETABLE_PMD_FOLDED > > >>>>> > > >>>>>Microblaze uses custom implementation of PMD folding, but doesn't define > > >>>>>__PAGETABLE_PMD_FOLDED, which generic code expects to see. Let's fix it. > > >>>>> > > >>>>>Defining __PAGETABLE_PMD_FOLDED will drop out unused __pmd_alloc(). > > >>>>>It also fixes problems with recently-introduced pmd accounting. > > >>>>> > > >>>>>Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > > >>>>>Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > >>>> > > >>>>Tested working. > > >>>> > > >>>>Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > >>>> > > >>>>Any idea how to fix the sh problem ? > > >>> > > >>>Can you tell us more about it? All I'm seeing is "qemu:sh fails to > > >>>shut down", which isn't very clear. > > >> > > >>Turns out that the include file defining __PAGETABLE_PMD_FOLDED > > >>was not always included where used, resulting in a messed up mm_struct. > > > > > >What means "messed up" here? It should only affect size of mm_struct. > > > > > Plus the offset of all variables after the #ifndef. > > Okay, I guess the problem is that different parts of the kernel see > different mm_struct depending on include ordering. > > Tried to look for options, but don't see anything better than patch below. > Andrew, is it okay to you? > > From 0f113e16a058d47f3bc63a3b6ced5296afb934a6 Mon Sep 17 00:00:00 2001 > From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > Date: Tue, 27 Jan 2015 17:59:55 +0200 > Subject: [PATCH] mm: add nr_pmds into mm_struct unconditionally > > __PAGETABLE_PMD_FOLDED is defined during <asm/pgtable.h> which is not > included into <linux/mm_types.h>. And we cannot include it here since > many of <asm/pgtables> needs <linux/mm_types.h> to define struct page. > > I failed to come up with better solution rather than put nr_pmds into > mm_struct unconditionally. > > One possible solution would be to expose number of page table levels > architecture has via Kconfig, but that's ugly and requires changes to > all architectures. > FWIW, I tried a number of approaches. Ultimately I gave up and concluded that it has to be either this patch or, as you say here, we would have to add something like PAGETABLE_PMD_FOLDED as a Kconfig option. > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Tested working with all builds and all my qemu tests. Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> Guenter -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>