From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Wilhelms Damasio - Taghos Subject: Task blocked on a ext4 partition Date: Mon, 15 Aug 2011 17:51:13 -0300 Message-ID: <4E4986C1.6090404@taghos.com.br> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from gateway07.websitewelcome.com ([69.56.176.23]:58809 "HELO gateway07.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751351Ab1HOVAx (ORCPT ); Mon, 15 Aug 2011 17:00:53 -0400 Received: from gator1481.hostgator.com (gator1481.hostgator.com [184.173.199.228]) by ham01.websitewelcome.com (Postfix) with ESMTP id 18E6C8DC83881 for ; Mon, 15 Aug 2011 15:51:16 -0500 (CDT) Received: from [201.21.231.127] (port=6505 helo=Felipe-Damasio.local) by gator1481.hostgator.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1Qt47u-00045c-S4 for netdev@vger.kernel.org; Mon, 15 Aug 2011 15:51:15 -0500 Sender: netdev-owner@vger.kernel.org List-ID: Hi All, I'm using a mmap-based file sharing system on an ext4 partition with epoll on an ISP. Last night the system got a significant slow down, and dmesg showed a lot of these: INFO: task fshare:23798 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. fshare D 0000000000000007 0 23798 17719 0x00000000 ffff88018af29648 0000000000000082 0000000000012500 ffff88018af29fd8 ffff88018af29fd8 ffff88042d371a40 0000000000012500 0000000000012500 0000000000012500 ffff88042d371a40 ffff88042e0d5550 ffff88042d371ce8 Call Trace: [] ? enqueue_entity+0x11f/0x127 [] schedule_timeout+0x22/0xda [] ? get_parent_ip+0x11/0x41 [] ? sub_preempt_count+0x92/0xa5 [] wait_for_common+0xca/0x140 [] ? default_wake_function+0x0/0xf [] wait_for_completion+0x18/0x1a [] writeback_inodes_sb+0xb4/0xbf [] writeback_inodes_sb_if_idle+0x37/0x4b [] ext4_da_write_begin+0xa5/0x1e6 [] ? find_lock_page+0x1e/0x5d [] ext4_page_mkwrite+0x117/0x168 [] __do_fault+0x125/0x388 [] ? get_parent_ip+0x11/0x41 [] handle_mm_fault+0x429/0x838 [] do_page_fault+0x222/0x239 [] page_fault+0x1f/0x30 [] ? copy_user_generic_string+0x2d/0x40 [] ? memcpy_toiovec+0x37/0x66 [] skb_copy_datagram_iovec+0x4b/0x1cf [] ? get_parent_ip+0x11/0x41 [] tcp_recvmsg+0x746/0xa62 [] inet_recvmsg+0x5a/0x78 [] __sock_recvmsg+0x7b/0x87 [] sock_recvmsg+0xa6/0xbf [] ? tcp_poll+0x2b/0x180 [] ? fget_light+0x93/0xa9 [] ? sockfd_lookup_light+0x1b/0x53 [] sys_recvfrom+0xb0/0xfe [] ? sys_epoll_wait+0x28f/0x2a7 [] system_call_fastpath+0x16/0x1b Do you have any idea what could cause this? The kernel I'm using is 2.6.35.13. Is there any other info I can provide to help track this down? Cheers, -- Felipe Wilhelms Damasio TAGHOS - Tecnologia Rua Prof. Alvaro Alvim, 211 Porto Alegre - RS - (51) 3239-3180 www.taghos.com.br