From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932511AbbFSUlr (ORCPT ); Fri, 19 Jun 2015 16:41:47 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51430 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932369AbbFSUkI (ORCPT ); Fri, 19 Jun 2015 16:40:08 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mel Gorman , Jovi Zhangwei , Ingo Molnar , Peter Zijlstra , Andrew Morton , Linus Torvalds Subject: [PATCH 4.0 093/105] sched, numa: do not hint for NUMA balancing on VM_MIXEDMAP mappings Date: Fri, 19 Jun 2015 13:36:23 -0700 Message-Id: <20150619203600.990781868@linuxfoundation.org> X-Mailer: git-send-email 2.4.4 In-Reply-To: <20150619203558.187802739@linuxfoundation.org> References: <20150619203558.187802739@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mel Gorman commit 8e76d4eecf7afeec9328e21cd5880e281838d0d6 upstream. Jovi Zhangwei reported the following problem Below kernel vm bug can be triggered by tcpdump which mmaped a lot of pages with GFP_COMP flag. [Mon May 25 05:29:33 2015] page:ffffea0015414000 count:66 mapcount:1 mapping: (null) index:0x0 [Mon May 25 05:29:33 2015] flags: 0x20047580004000(head) [Mon May 25 05:29:33 2015] page dumped because: VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page)) [Mon May 25 05:29:33 2015] ------------[ cut here ]------------ [Mon May 25 05:29:33 2015] kernel BUG at mm/migrate.c:1661! [Mon May 25 05:29:33 2015] invalid opcode: 0000 [#1] SMP In this case it was triggered by running tcpdump but it's not necessary reproducible on all systems. sudo tcpdump -i bond0.100 'tcp port 4242' -c 100000000000 -w 4242.pcap Compound pages cannot be migrated and it was not expected that such pages be marked for NUMA balancing. This did not take into account that drivers such as net/packet/af_packet.c may insert compound pages into userspace with vm_insert_page. This patch tells the NUMA balancing protection scanner to skip all VM_MIXEDMAP mappings which avoids the possibility that compound pages are marked for migration. Signed-off-by: Mel Gorman Reported-by: Jovi Zhangwei Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2166,7 +2166,7 @@ void task_numa_work(struct callback_head } for (; vma; vma = vma->vm_next) { if (!vma_migratable(vma) || !vma_policy_mof(vma) || - is_vm_hugetlb_page(vma)) { + is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) { continue; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/