From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Straus Subject: Lockdep traceback under heavy load Date: Mon, 20 Nov 2006 11:52:36 -0800 Message-ID: <20061120195236.GE25908@hydra> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mmsmtp.merfinllc.com ([63.73.180.145]:47039 "EHLO mule.merfinllc.com") by vger.kernel.org with ESMTP id S966598AbWKTTwi (ORCPT ); Mon, 20 Nov 2006 14:52:38 -0500 Received: from mule.merfinllc.com (localhost [127.0.0.1]) by mule.merfinllc.com (8.13.4/8.13.4/Debian-3sarge3) with ESMTP id kAKJqa6A010421 for ; Mon, 20 Nov 2006 11:52:37 -0800 Received: (from aaron@localhost) by mule.merfinllc.com (8.13.4/8.13.4/Submit) id kAKJqaEK010420 for netdev@vger.kernel.org; Mon, 20 Nov 2006 11:52:36 -0800 To: netdev@vger.kernel.org Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi, I got a lockdep traceback recently. The machine is a i386 dell inspiron 700m running 2.6.19-rc6. I was putting NFS through a workout at the time. This was the mount I was putting through a workout: mamba:/export/data on /mnt/merfin/data type nfs (ro,rsize=8192,wsize=8192,hard,intr,addr=...) firefox was using a different mount to a different machine. I sent this to Trond originally who suggested sending it to netdev. If you want any more information, let me know. Regards, =aaron= Here is the traceback: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.19-rc6-asb #8 ------------------------------------------------------- firefox-bin/6488 is trying to acquire lock: (&mm->mmap_sem){----}, at: [] do_page_fault+0x19f/0x562 but task is already holding lock: (sk_lock-AF_INET){--..}, at: [] tcp_recvmsg+0x13/0x6fb which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_INET){--..}: [] add_lock_to_list+0x62/0x7e [] __lock_acquire+0x8b1/0x9a9 [] lock_acquire+0x5a/0x78 [] lock_sock+0xce/0xdb [] udp_sendmsg+0x36c/0x517 [] inet_sendmsg+0x45/0x4f [] sock_sendmsg+0xda/0xf2 [] kernel_sendmsg+0x3d/0x4e [] xs_udp_send_request+0x10d/0x295 [sunrpc] [] xprt_transmit+0xd5/0x1d5 [sunrpc] [] call_transmit+0x1d0/0x1fe [sunrpc] [] __rpc_execute+0x89/0x1be [sunrpc] [] rpc_execute+0x15/0x17 [sunrpc] [] nfs_execute_read+0x3f/0x58 [nfs] [] nfs_pagein_one+0x212/0x22a [nfs] [] nfs_readpages+0x166/0x1d6 [nfs] [] __do_page_cache_readahead+0x14b/0x20f [] do_page_cache_readahead+0x48/0x51 [] filemap_nopage+0x1a2/0x3ad [] __handle_mm_fault+0x148/0x847 [] do_page_fault+0x23f/0x562 [] error_code+0x39/0x40 [] 0xffffffff -> #0 (&mm->mmap_sem){----}: [] print_circular_bug_tail+0x30/0x66 [] __lock_acquire+0x7b0/0x9a9 [] lock_acquire+0x5a/0x78 [] down_read+0x50/0x61 [] do_page_fault+0x19f/0x562 [] error_code+0x39/0x40 [] copy_to_user+0x58/0x66 [] memcpy_toiovec+0x34/0x5a [] skb_copy_datagram_iovec+0x4d/0x1c1 [] tcp_recvmsg+0x451/0x6fb [] sock_common_recvmsg+0x4d/0x62 [] sock_recvmsg+0xe5/0xfe [] sys_recvfrom+0x9d/0xec [] sys_recv+0x36/0x38 [] sys_socketcall+0x178/0x22d [] sysenter_past_esp+0x56/0x8d [] 0xffffffff other info that might help us debug this: 1 lock held by firefox-bin/6488: #0: (sk_lock-AF_INET){--..}, at: [] tcp_recvmsg+0x13/0x6fb stack backtrace: [] dump_trace+0x76/0x1ed [] show_trace_log_lvl+0x26/0x3c [] show_trace+0x19/0x1b [] dump_stack+0x26/0x28 [] print_circular_bug_tail+0x5d/0x66 [] __lock_acquire+0x7b0/0x9a9 [] lock_acquire+0x5a/0x78 [] down_read+0x50/0x61 [] do_page_fault+0x19f/0x562 [] error_code+0x39/0x40 DWARF2 unwinder stuck at error_code+0x39/0x40 Leftover inexact backtrace: [] copy_to_user+0x58/0x66 [] memcpy_toiovec+0x34/0x5a [] skb_copy_datagram_iovec+0x4d/0x1c1 [] tcp_recvmsg+0x451/0x6fb [] sock_common_recvmsg+0x4d/0x62 [] sock_recvmsg+0xe5/0xfe [] sys_recvfrom+0x9d/0xec [] sys_recv+0x36/0x38 [] sys_socketcall+0x178/0x22d [] sysenter_past_esp+0x56/0x8d ======================= -- =================== Aaron Straus aaron@merfinllc.com