From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f50.google.com (mail-qg0-f50.google.com [209.85.192.50]) by kanga.kvack.org (Postfix) with ESMTP id 1D41A6B0035 for ; Thu, 29 May 2014 23:05:06 -0400 (EDT) Received: by mail-qg0-f50.google.com with SMTP id z60so3737211qgd.9 for ; Thu, 29 May 2014 20:05:05 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id x9si3522343qcs.20.2014.05.29.20.05.05 for ; Thu, 29 May 2014 20:05:05 -0700 (PDT) Message-ID: <5387f561.8983e50a.1ead.ffff85b1SMTPIN_ADDED_BROKEN@mx.google.com> From: Naoya Horiguchi Subject: Re: [PATCH] hugetlb: restrict hugepage_migration_support() to x86_64 (Re: BUG at mm/memory.c:1489!) Date: Thu, 29 May 2014 23:04:50 -0400 In-Reply-To: <1401413716.29324.2.camel@concordia> References: <1401265922.3355.4.camel@concordia> <1401353983.4930.15.camel@concordia> <1401388474-mqnis5cp@n-horiguchi@ah.jp.nec.com> <1401413716.29324.2.camel@concordia> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: mpe@ellerman.id.au Cc: Hugh Dickins , Andrew Morton , benh@kernel.crashing.org, Tony Luck , linux-mm@kvack.org, linux-kernel@vger.kernel.org, trinity@vger.kernel.org On Fri, May 30, 2014 at 11:35:16AM +1000, Michael Ellerman wrote: > On Thu, 2014-05-29 at 14:34 -0400, Naoya Horiguchi wrote: > > On Thu, May 29, 2014 at 06:59:43PM +1000, Michael Ellerman wrote: > > > Applying your patch and running trinity pretty immediately results in the > > > following, which looks related (sys_move_pages() again) ? > > > > > > Unable to handle kernel paging request for data at address 0xf2000f80000000 > > > Faulting instruction address: 0xc0000000001e29bc > > > cpu 0x1b: Vector: 300 (Data Access) at [c0000003c70f76f0] > > > pc: c0000000001e29bc: .remove_migration_pte+0x9c/0x320 > > > lr: c0000000001e29b8: .remove_migration_pte+0x98/0x320 > > > sp: c0000003c70f7970 > > > msr: 8000000000009032 > > > dar: f2000f80000000 > > > dsisr: 40000000 > > > current = 0xc0000003f9045800 > > > paca = 0xc000000001dc6c00 softe: 0 irq_happened: 0x01 > > > pid = 3585, comm = trinity-c27 > > > enter ? for help > > > [c0000003c70f7a20] c0000000001bce88 .rmap_walk+0x328/0x470 > > > [c0000003c70f7ae0] c0000000001e2904 .remove_migration_ptes+0x44/0x60 > > > [c0000003c70f7b80] c0000000001e4ce8 .migrate_pages+0x6d8/0xa00 > > > [c0000003c70f7cc0] c0000000001e55ec .SyS_move_pages+0x5dc/0x7d0 > > > [c0000003c70f7e30] c00000000000a1d8 syscall_exit+0x0/0x98 > > > --- Exception: c01 (System Call) at 00003fff7b2b30a8 > > > SP (3fffe09728a0) is in userspace > > > 1b:mon> > > > > Sorry for inconvenience on your testing. > > That's fine, it's good to find bugs :) > > > Hugepage migration is enabled for archs which have pmd-level hugepage > > (including ppc64,) but not tested except for x86_64. > > hugepage_migration_support() controls this so the following patch should > > help you avoid the problem, I believe. > > Could you try to test with it? > > Sure. So this patch, in addition to Hugh's patch to remove the BUG_ON(), does > avoid the crash above (remove_migration_pte()). > > I dropped Hugh's patch, as he has decided he doesn't like it, and added the > following hunk instead: > > diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h > index 3c1b968..f230a97 100644 > --- a/include/linux/mempolicy.h > +++ b/include/linux/mempolicy.h > @@ -175,6 +175,12 @@ static inline int vma_migratable(struct vm_area_struct *vma) > { > if (vma->vm_flags & (VM_IO | VM_PFNMAP)) > return 0; > + > +#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION > + if (vma->vm_flags & VM_HUGETLB) > + return 0; > +#endif > + > /* > * Migration allocates pages in the highest zone. If we cannot > * do so then migration (at least from node to node) is not > > > Which seems to be what Hugh was referring to in his mail - correct me if I'm > wrong Hugh. > > With your patch and the above hunk I can run trinity happily for a while, > whereas without it crashes almost immediately. Great. > So with the above hunk you can add my tested-by. OK, thank you for your help. I'll post the revised patch later. Thanks, Naoya Horiguchi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org