From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com [209.85.220.46]) by kanga.kvack.org (Postfix) with ESMTP id C46126B0035 for ; Tue, 24 Dec 2013 19:35:23 -0500 (EST) Received: by mail-pa0-f46.google.com with SMTP id kp14so5025822pab.5 for ; Tue, 24 Dec 2013 16:35:23 -0800 (PST) Received: from e28smtp03.in.ibm.com (e28smtp03.in.ibm.com. [122.248.162.3]) by mx.google.com with ESMTPS id dv5si16785135pbb.133.2013.12.24.16.35.20 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 24 Dec 2013 16:35:22 -0800 (PST) Received: from /spool/local by e28smtp03.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Dec 2013 06:05:19 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 23D663940057 for ; Wed, 25 Dec 2013 06:05:17 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rBP0ZCPY54853874 for ; Wed, 25 Dec 2013 06:05:13 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rBP0ZFkp009578 for ; Wed, 25 Dec 2013 06:05:15 +0530 Date: Wed, 25 Dec 2013 08:35:13 +0800 From: Wanpeng Li Subject: Re: [PATCH] mm/thp: fix vmas tear down race with thp splitting Message-ID: <52ba284a.e560440a.7eeb.ffff92bcSMTPIN_ADDED_BROKEN@mx.google.com> Reply-To: Wanpeng Li References: <1387850059-18525-1-git-send-email-liwanp@linux.vnet.ibm.com> <52B9A65D.8060300@oracle.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="CUfgB8w4ZwR/yMy5" Content-Disposition: inline In-Reply-To: <52B9A65D.8060300@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Andrea Arcangeli , Andrew Morton , "Kirill A. Shutemov" , Dave Jones , linux-mm@kvack.org, linux-kernel@vger.kernel.org --CUfgB8w4ZwR/yMy5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Cc Andrea, On Tue, Dec 24, 2013 at 10:21:01AM -0500, Sasha Levin wrote: >On 12/23/2013 08:54 PM, Wanpeng Li wrote: >>Sasha reports unmap_page_range tears down pmd range which is race with thp >>splitting during page reclaim. Transparent huge page will be splitting >>during page reclaim. However, split pmd lock which held by __split_trans_huge_lock >>can't prevent __split_huge_page_refcount running in parallel. This patch fix >>it by hold compound lock to check if __split_huge_page_refcount is running >>underneath, in that case zap huge pmd range should be fallback. >> >>[ 265.474585] kernel BUG at mm/huge_memory.c:1440! >>[ 265.475129] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC >>[ 265.476684] Dumping ftrace buffer: >>[ 265.477144] (ftrace buffer empty) >>[ 265.478398] Modules linked in: >>[ 265.478807] CPU: 8 PID: 11344 Comm: trinity-c206 Tainted: G W 3.13.0-rc5-next-20131223-sasha-00015-gec22156-dirty #8 >>[ 265.480172] task: ffff8801cb573000 ti: ffff8801cbd3a000 task.ti: ffff8801cbd3a000 >>[ 265.480172] RIP: 0010:[] [] zap_huge_pmd+0x170/0x1f0 >>[ 265.480172] RSP: 0000:ffff8801cbd3bc78 EFLAGS: 00010246 >>[ 265.480172] RAX: 015fffff80090018 RBX: ffff8801cbd3bde8 RCX: ffffffffffffff9c >>[ 265.480172] RDX: ffffffffffffffff RSI: 0000000000000008 RDI: ffff8800bffd2000 >>[ 265.480172] RBP: ffff8801cbd3bcb8 R08: 0000000000000000 R09: 0000000000000000 >>[ 265.480172] R10: 0000000000000001 R11: 0000000000000000 R12: ffffea0002856740 >>[ 265.480172] R13: ffffea0002d50000 R14: 00007ff915000000 R15: 00007ff930e48fff >>[ 265.480172] FS: 00007ff934899700(0000) GS:ffff88014d400000(0000) knlGS:0000000000000000 >>[ 265.480172] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>[ 265.480172] CR2: 00007ff93428a000 CR3: 000000010babe000 CR4: 00000000000006e0 >>[ 265.480172] Stack: >>[ 265.480172] 00000000000004dd ffff8801ccbfbb60 ffff8801cbd3bcb8 ffff8801cbb15540 >>[ 265.480172] 00007ff915000000 00007ff930e49000 ffff8801cbd3bde8 00007ff930e48fff >>[ 265.480172] ffff8801cbd3bd48 ffffffff812885b6 ffff88005f5d20c0 00007ff915200000 >>[ 265.480172] Call Trace: >>[ 265.480172] [] unmap_page_range+0x2c6/0x410 >>[ 265.480172] [] unmap_single_vma+0x101/0x120 >>[ 265.480172] [] unmap_vmas+0x61/0xa0 >>[ 265.480172] [] exit_mmap+0xd0/0x170 >>[ 265.480172] [] mmput+0x70/0xe0 >>[ 265.480172] [] exit_mm+0x18d/0x1a0 >>[ 265.480172] [] ? acct_collect+0x175/0x1b0 >>[ 265.480172] [] do_exit+0x26f/0x520 >>[ 265.480172] [] do_group_exit+0xa9/0xe0 >>[ 265.480172] [] SyS_exit_group+0x17/0x20 >>[ 265.480172] [] tracesys+0xdd/0xe2 >>[ 265.480172] Code: 0f 0b 66 0f 1f 84 00 00 00 00 00 eb fe 66 0f 1f >>44 00 00 48 8b 03 f0 48 81 80 50 03 00 00 00 fe ff ff 49 8b 45 00 f6 >>c4 40 75 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 48 8b 03 >>f0 48 >>[ 265.480172] RIP [] zap_huge_pmd+0x170/0x1f0 >>[ 265.480172] RSP >> >>Reported-by: Sasha Levin >>Signed-off-by: Wanpeng Li >>--- > >Ran a round of testing overnight. While the BUG seems to be gone I'm now getting: > > Ah, I think the patch below fix it. However, as Kirill point out, we still need to figure out the root issue. Regards, Wanpeng Li > >Thanks, >Sasha --CUfgB8w4ZwR/yMy5 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="0001-2.patch" --CUfgB8w4ZwR/yMy5--