From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id 705A56B0253 for ; Fri, 13 Nov 2015 03:34:00 -0500 (EST) Received: by wmww144 with SMTP id w144so20322451wmw.0 for ; Fri, 13 Nov 2015 00:33:59 -0800 (PST) Received: from mail-wm0-x22a.google.com (mail-wm0-x22a.google.com. [2a00:1450:400c:c09::22a]) by mx.google.com with ESMTPS id 193si4064383wmx.83.2015.11.13.00.33.59 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Nov 2015 00:33:59 -0800 (PST) Received: by wmvv187 with SMTP id v187so69932269wmv.1 for ; Fri, 13 Nov 2015 00:33:59 -0800 (PST) Date: Fri, 13 Nov 2015 10:33:57 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH v1] mm: fix mapcount mismatch in hugepage migration Message-ID: <20151113083357.GA28904@node.shutemov.name> References: <1447375469-9298-1-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1447375469-9298-1-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi On Fri, Nov 13, 2015 at 09:44:29AM +0900, Naoya Horiguchi wrote: > try_to_unmap_one() should be able to handle hugetlb, but page_remove_rmap() > in that function takes false as a compound flag, which breaks hugepage migration > with the following message. > > Soft offlining page 0x1d4a00 at 0x7ff634a00000 > soft offline: 0x1d4a00: migration failed 1, type 60000000000401c > BUG: Bad page state in process sysctl pfn:1d4a00 > page:ffffea0007528000 count:0 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 10 > flags: 0x600000000004008(uptodate|head) > page dumped because: nonzero mapcount > Modules linked in: cfg80211 rfkill crc32c_intel virtio_balloon serio_raw i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi > CPU: 3 PID: 11882 Comm: sysctl Tainted: G W 4.3.0-mmotm-2015-11-10-15-53-151112-1812-00015-53+ #240 > Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > ffffffff81a1a124 ffff8800da047bd0 ffffffff81340adf ffffea0007528000 > ffff8800da047bf8 ffffffff8116e206 0000000000000009 ffffffff81f72538 > ffffea0007528000 ffff8800da047c48 ffffffff8116e6d6 0000020000000000 > Call Trace: > [] dump_stack+0x44/0x55 > [] bad_page+0xc6/0x110 > [] free_pages_prepare+0x486/0x500 > [] __free_pages_ok+0x1a/0xb0 > [] __free_pages+0x21/0x40 > [] update_and_free_page+0xa9/0x230 > [] free_pool_huge_page+0xc1/0xe0 > [] set_max_huge_pages+0x382/0x4d0 > [] hugetlb_sysctl_handler_common+0xa2/0xd0 > [] hugetlb_sysctl_handler+0x1e/0x20 > [] proc_sys_call_handler+0xae/0xc0 > [] proc_sys_write+0x14/0x20 > [] __vfs_write+0x28/0xe0 > [] ? percpu_down_read+0x14/0x60 > [] vfs_write+0xa9/0x190 > [] SyS_write+0x46/0xb0 > [] entry_SYSCALL_64_fastpath+0x12/0x6a > > This patch simply fixes this by giving the compound flag via PageHuge. > --- > # This patch is against mmotm-2015-11-10-15-53 as a fix for "rmap: add argument > # to charge compound page". > > Signed-off-by: Naoya Horiguchi Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov -- 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