Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753054Ab1DSPqy (ORCPT ); Tue, 19 Apr 2011 11:46:54 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:52676 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687Ab1DSPqw (ORCPT ); Tue, 19 Apr 2011 11:46:52 -0400 Subject: Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards From: James Bottomley To: Michal Hocko Cc: Andrew Morton , Hugh Dickins , linux-mm@kvack.org, LKML , linux-parisc@vger.kernel.org In-Reply-To: <20110419111004.GE21689@tiehlicka.suse.cz> References: <20110415135144.GE8828@tiehlicka.suse.cz> <20110418100131.GD8925@tiehlicka.suse.cz> <20110418135637.5baac204.akpm@linux-foundation.org> <20110419111004.GE21689@tiehlicka.suse.cz> Content-Type: text/plain; charset="UTF-8" Date: Tue, 19 Apr 2011 10:46:49 -0500 Message-ID: <1303228009.3171.18.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6509 Lines: 124 On Tue, 2011-04-19 at 13:10 +0200, Michal Hocko wrote: > On Mon 18-04-11 13:56:37, Andrew Morton wrote: > > On Mon, 18 Apr 2011 12:01:31 +0200 > > Michal Hocko wrote: > > > > > Currently we have expand_upwards exported while expand_downwards is > > > accessible only via expand_stack or expand_stack_downwards. > > > > > > check_stack_guard_page is a nice example of the asymmetry. It uses > > > expand_stack for VM_GROWSDOWN while expand_upwards is called for > > > VM_GROWSUP case. > > > > > > Let's clean this up by exporting both functions and make those name > > > consistent. Let's use expand_stack_{upwards,downwards} so that we are > > > explicit about stack manipulation in the name. expand_stack_downwards > > > has to be defined for both CONFIG_STACK_GROWS{UP,DOWN} because > > > get_arg_page calls the downwards version in the early process > > > initialization phase for growsup configuration. > > > > Has this patch been tested on any stack-grows-upwards architecture? > > The only one I can find in the tree is parisc and I do not have access > to any such machine. Maybe someone on the list (CCed) can help with > testing the patch bellow? Nevertheless, the patch doesn't change growsup > case. It just renames functions and exports growsdown. It compiles OK, but crashes on boot in fsck. The crash is definitely mm but looks to be a slab problem (it's a null deref on a spinlock in add_partial(), which seems unrelated to this patch). [ 15.628000] sd 1:0:2:0: [sdc] Attached SCSI disk done. [ 16.632000] EXT3-fs: barriers not enabled [ 16.640000] kjournald starting. Commit interval 5 seconds [ 16.640000] EXT3-fs (sda3): mounted filesystem with ordered data mode Begin: Running /scripts/local-bottom ... done. done. Begin: Running /scripts/init-bottom ... done. INIT: version 2.88 booting Setting hostname to 'ion'...done. Starting the hotplug events dispatcher: udevd[ 22.008000] udev[211]: starting version 164 . Synthesizing the initial hotplug events...done. Waiting for /dev to be fully populated...done. Activating swap:swapon on /dev/sda2 swapon: /dev/sda2: found swap signature: version 1, page-size 4, same byte order swapon: /dev/sda2: pagesize=4096, swapsize=1028157440, devsize=1028160000 [ 28.780000] Adding 1004056k swap on /dev/sda2. Priority:-1 extents:1 across:1004056k . Will now check root file system:fsck from util-linux-ng 2.17.2 [/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a -C0 /dev/sda3 /dev/sda3 has been mounted 37 times without being checked, check forced. [ 257.192000] Backtrace:=========== \ 42.8% [ 257.192000] [<0000000040214f78>] add_partial+0x28/0x98 [ 257.192000] [<0000000040217ff8>] __slab_free+0x1d0/0x1d8 [ 257.192000] [<000000004021825c>] kmem_cache_free+0xc4/0x128 [ 257.192000] [<00000000401fd1a4>] remove_vma+0x8c/0xc0 [ 257.192000] [<00000000401fd3a8>] exit_mmap+0x1d0/0x220 [ 257.192000] [<0000000040156514>] mmput+0xd4/0x200 [ 257.192000] [<000000004015c7b8>] exit_mm+0x100/0x2c0 [ 257.192000] [<000000004015ef40>] do_exit+0x778/0x9d8 [ 257.192000] [<000000004015f1ec>] do_group_exit+0x4c/0xe0 [ 257.192000] [<000000004015f298>] sys_exit_group+0x18/0x28 [ 257.192000] [<0000000040106034>] syscall_exit+0x0/0x14 [ 257.192000] [ 257.192000] [ 257.192000] Kernel Fault: Code=26 regs=00000040bf1807d0 (Addr=0000000000000000) [ 257.192000] [ 257.192000] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI [ 257.192000] PSW: 00001000000001001111000000001110 Not tainted [ 257.192000] r00-03 000000ff0804f00e 0000000040769e40 0000000040214f78 0000000000000000 [ 257.192000] r04-07 0000000040746e40 0000000000000001 0000004080ded370 0000000000000001 [ 257.192000] r08-11 0000000040654150 0000000000000000 0000000000000001 0000000000000001 [ 257.192000] r12-15 0000000000000000 00000000ffffffff 0000000000000024 0000000000000000 [ 257.192000] r16-19 00000000fb4ead9c 00000000fb4eac54 0000000000000000 0000000000000000 [ 257.192000] r20-23 000000000800000e 0000000000000001 000000007bbb7180 00000000401fd1a4 [ 257.192000] r24-27 0000000000000001 0000004080ded370 0000000000000000 0000000040746e40 [ 257.192000] r28-31 000000007ec0a908 00000040bf1807a0 00000040bf1807d0 0000000000000016 [ 257.192000] sr00-03 00000000002d9000 0000000000000000 0000000000000000 00000000002d9000 [ 257.192000] sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 257.192000] [ 257.192000] IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004011bbc0 000000004011bbc4 [ 257.192000] IIR: 0f4015dc ISR: 0000000000000000 IOR: 0000000000000000 [ 257.192000] CPU: 0 CR30: 00000040bf180000 CR31: fffffff0f0e098e0 [ 257.192000] ORIG_R28: 0000000040769e40 [ 257.192000] IAOQ[0]: _raw_spin_lock+0x0/0x20 [ 257.192000] IAOQ[1]: _raw_spin_lock+0x4/0x20 [ 257.192000] RP(r2): add_partial+0x28/0x98 [ 257.192000] Backtrace: [ 257.192000] [<0000000040214f78>] add_partial+0x28/0x98 [ 257.192000] [<0000000040217ff8>] __slab_free+0x1d0/0x1d8 [ 257.192000] [<000000004021825c>] kmem_cache_free+0xc4/0x128 [ 257.192000] [<00000000401fd1a4>] remove_vma+0x8c/0xc0 [ 257.192000] [<00000000401fd3a8>] exit_mmap+0x1d0/0x220 [ 257.192000] [<0000000040156514>] mmput+0xd4/0x200 [ 257.192000] [<000000004015c7b8>] exit_mm+0x100/0x2c0 [ 257.192000] [<000000004015ef40>] do_exit+0x778/0x9d8 [ 257.192000] [<000000004015f1ec>] do_group_exit+0x4c/0xe0 [ 257.192000] [<000000004015f298>] sys_exit_group+0x18/0x28 [ 257.192000] [<0000000040106034>] syscall_exit+0x0/0x14 [ 257.192000] [ 257.192000] Kernel panic - not syncing: Kernel Fault [ 257.192000] Backtrace: [ 257.192000] [<000000004011f984>] show_stack+0x14/0x20 [ 257.192000] [<000000004011f9a8>] dump_stack+0x18/0x28 [ 257.192000] [<000000004015946c>] panic+0xd4/0x368 [ 257.192000] [<0000000040120024>] parisc_terminate+0x14c/0x170 [ 257.192000] [<000000004012059c>] handle_interruption+0x2ac/0x8f8 [ 257.192000] [<000000004011bbc0>] _raw_spin_lock+0x0/0x20 [ 257.192000] [ 257.192000] Rebooting in 5 seconds.. It seems to be a random intermittent mm crash because the next reboot crashed with the same trace but after the fsck had completed and the third came up to the login prompt. James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/