Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752999AbaJAWIs (ORCPT ); Wed, 1 Oct 2014 18:08:48 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:46497 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751793AbaJAWIr (ORCPT ); Wed, 1 Oct 2014 18:08:47 -0400 Message-ID: <542C7B5E.2020000@oracle.com> Date: Wed, 01 Oct 2014 18:08:30 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Linus Torvalds , Hugh Dickins CC: Dave Jones , Al Viro , Linux Kernel , Rik van Riel , Ingo Molnar , Michel Lespinasse , "Kirill A. Shutemov" , Mel Gorman Subject: Re: pipe/page fault oddness. References: <20140930033327.GA14558@redhat.com> <20140930043309.GA16196@redhat.com> <20140930160510.GA15903@redhat.com> <20140930162201.GC15903@redhat.com> <20140930164047.GA18354@redhat.com> <20140930182059.GA24431@redhat.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/01/2014 04:20 PM, Linus Torvalds wrote: > So I'm really sending this patch out in the hope that it will get > comments, fixup and possibly even testing by people who actually know > the NUMA balancing code. Rik? Anybody? Hi Linus, I've tried this patch on the same configuration that was triggering the VM_BUG_ON that Hugh mentioned previously. Surprisingly enough it ran fine for ~20 minutes before exploding with: [ 2781.566206] kernel BUG at mm/huge_memory.c:1293! [ 2781.566953] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 2781.568054] Dumping ftrace buffer: [ 2781.568826] (ftrace buffer empty) [ 2781.569392] Modules linked in: [ 2781.569909] CPU: 61 PID: 13111 Comm: trinity-c61 Not tainted 3.17.0-rc7-sasha-00040-g65e1cb2 #1259 [ 2781.571077] task: ffff88050ba80000 ti: ffff880418ecc000 task.ti: ffff880418ecc000 [ 2781.571077] RIP: do_huge_pmd_numa_page (mm/huge_memory.c:1293 (discriminator 1)) [ 2781.571077] RSP: 0000:ffff880418ecfc60 EFLAGS: 00010246 [ 2781.571077] RAX: ffffea0074c60000 RBX: ffffea0074c60000 RCX: 0000001d318009e0 [ 2781.571077] RDX: ffffea0000000000 RSI: ffffffffb5706ef3 RDI: 0000001d318009e0 [ 2781.571077] RBP: ffff880418ecfcc8 R08: 0000000000000038 R09: 0000000000000001 [ 2781.571077] R10: 0000000000000038 R11: 0000000000000001 R12: ffff8804f9b52000 [ 2781.571077] R13: 0000001d318009e0 R14: ffff880508a1f840 R15: 0000000000000028 [ 2781.571077] FS: 00007f5502fc9700(0000) GS:ffff881d77e00000(0000) knlGS:0000000000000000 [ 2781.571077] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2781.571077] CR2: 0000000000000000 CR3: 00000004bfac4000 CR4: 00000000000006a0 [ 2781.571077] Stack: [ 2781.571077] ffff880418ecfc98 0000000000000282 ffff88050ba80000 000000000000000b [ 2781.571077] ffff88060d2ab000 ffff88060000001d 0000000000000000 ffff881d30b3ec00 [ 2781.571077] 0000000000000000 ffff881d30b3ec00 ffff88060d2ab000 0000000000000100 [ 2781.571077] Call Trace: [ 2781.571077] handle_mm_fault (mm/memory.c:3304 mm/memory.c:3368) [ 2781.571077] __do_page_fault (arch/x86/mm/fault.c:1231) [ 2781.571077] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:90 arch/x86/kernel/kvmclock.c:86) [ 2781.571077] ? sched_clock (./arch/x86/include/asm/paravirt.h:192 arch/x86/kernel/tsc.c:304) [ 2781.571077] ? sched_clock_local (kernel/sched/clock.c:214) [ 2781.571077] ? context_tracking_user_exit (kernel/context_tracking.c:184) [ 2781.571077] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63) [ 2781.571077] ? trace_hardirqs_off_caller (kernel/locking/lockdep.c:2641 (discriminator 8)) [ 2781.571077] trace_do_page_fault (arch/x86/mm/fault.c:1314 include/linux/jump_label.h:115 include/linux/context_tracking_state.h:27 include/linux/context_tracking.h:45 arch/x86/mm/fault.c:1315) [ 2781.571077] do_async_page_fault (arch/x86/kernel/kvm.c:279) [ 2781.571077] async_page_fault (arch/x86/kernel/entry_64.S:1314) [ 2781.571077] ? copy_user_generic_unrolled (arch/x86/lib/copy_user_64.S:166) [ 2781.571077] ? sys32_mmap (arch/x86/ia32/sys_ia32.c:159) [ 2781.571077] ia32_do_call (arch/x86/ia32/ia32entry.S:430) [ 2781.571077] Code: b4 eb e0 0f 1f 84 00 00 00 00 00 4c 89 f7 e8 88 2f 0c 03 48 8b 45 d0 4c 89 e6 48 8b b8 88 00 00 00 e8 85 c7 ff ff e9 90 fe ff ff <0f> 0b 66 0f 1f 44 00 00 48 89 df e8 90 e9 f9 ff 84 c0 0f 85 be All code ======== 0: b4 eb mov $0xeb,%ah 2: e0 0f loopne 0x13 4: 1f (bad) 5: 84 00 test %al,(%rax) 7: 00 00 add %al,(%rax) 9: 00 00 add %al,(%rax) b: 4c 89 f7 mov %r14,%rdi e: e8 88 2f 0c 03 callq 0x30c2f9b 13: 48 8b 45 d0 mov -0x30(%rbp),%rax 17: 4c 89 e6 mov %r12,%rsi 1a: 48 8b b8 88 00 00 00 mov 0x88(%rax),%rdi 21: e8 85 c7 ff ff callq 0xffffffffffffc7ab 26: e9 90 fe ff ff jmpq 0xfffffffffffffebb 2b:* 0f 0b ud2 <-- trapping instruction 2d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 33: 48 89 df mov %rbx,%rdi 36: e8 90 e9 f9 ff callq 0xfffffffffff9e9cb 3b: 84 c0 test %al,%al 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: be .byte 0xbe ... Code starting with the faulting instruction =========================================== 0: 0f 0b ud2 2: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 8: 48 89 df mov %rbx,%rdi b: e8 90 e9 f9 ff callq 0xfffffffffff9e9a0 10: 84 c0 test %al,%al 12: 0f .byte 0xf 13: 85 .byte 0x85 14: be .byte 0xbe ... [ 2781.571077] RIP do_huge_pmd_numa_page (mm/huge_memory.c:1293 (discriminator 1)) [ 2781.571077] RSP Thanks, Sasha -- 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/