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. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> --- include/linux/mm_types.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 79cdf6f5c746..199a03aab8dc 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -364,9 +364,7 @@ struct mm_struct { atomic_t mm_users; /* How many users with user space? */ atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ atomic_long_t nr_ptes; /* PTE page table pages */ -#ifndef __PAGETABLE_PMD_FOLDED atomic_long_t nr_pmds; /* PMD page table pages */ -#endif int map_count; /* number of VMAs */ spinlock_t page_table_lock; /* Protects page tables and some counters */ -- Kirill A. Shutemov -- 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>