From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Wilhelms Damasio - Taghos Subject: Ext4 flush blocked Date: Thu, 14 Jul 2011 22:33:47 -0300 Message-ID: <4E1F98FB.8020800@taghos.com.br> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org Return-path: Received: from gateway07.websitewelcome.com ([69.56.236.22]:33035 "HELO gateway07.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S932217Ab1GOBeE (ORCPT ); Thu, 14 Jul 2011 21:34:04 -0400 Received: from gator1481.hostgator.com (gator1481.hostgator.com [184.173.199.228]) by ham01.websitewelcome.com (Postfix) with ESMTP id 4FC7A4ECA57EA for ; Thu, 14 Jul 2011 20:33:58 -0500 (CDT) Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, I'm using a mmap-intensive file server on a Dell Machine with 2.6.35.13. The partition is a RAID-0 mounted with ext4 and noatime. After a while using (about an hour) I get a lot of: INFO: task flush-8:16:6650 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-8:16 D 0000000000000000 0 6650 2 0x00000000 ffff880400b0d980 0000000000000046 0000000000012500 ffff880400b0dfd8 ffff880400b0dfd8 ffff880418b34830 0000000000012500 0000000000012500 0000000000012500 ffff880418b34830 ffffffff81a11020 ffff880418b34ad8 Call Trace: [] io_schedule+0x7b/0xc2 [] sync_page+0x41/0x45 [] __wait_on_bit_lock+0x45/0x8c [] ? sync_page+0x0/0x45 [] __lock_page+0x63/0x6a [] ? wake_bit_function+0x0/0x2a [] ? unlock_page+0x22/0x27 [] ext4_da_writepages+0x516/0x8e1 [] ? find_busiest_group+0x2e9/0x900 [] do_writepages+0x1c/0x25 [] writeback_single_inode+0xe8/0x329 [] writeback_sb_inodes+0x14e/0x225 [] writeback_inodes_wb+0x146/0x156 [] wb_writeback+0x1b0/0x232 [] ? get_parent_ip+0x11/0x41 [] wb_do_writeback+0x139/0x14f [] bdi_writeback_task+0x3e/0x112 [] ? bit_waitqueue+0x12/0xa3 [] ? bdi_start_fn+0x0/0xd2 [] bdi_start_fn+0x71/0xd2 [] ? bdi_start_fn+0x0/0xd2 [] kthread+0x7d/0x85 [] kernel_thread_helper+0x4/0x10 [] ? kthread+0x0/0x85 [] ? kernel_thread_helper+0x0/0x10 The hardware is: 02:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08) The machine is RAID-0 with 2 450GB SAS 15K RPM hard drives. sd 0:2:1:0: [sdb] 1755840512 512-byte logical blocks: (898 GB/837 GiB) sd 0:2:1:0: [sdb] Write Protect is off sd 0:2:1:0: [sdb] Mode Sense: 1f 00 00 08 scsi 0:0:32:0: Attached scsi generic sg0 type 13 sd 0:2:1:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 0:2:0:0: Attached scsi generic sg1 type 0 sd 0:2:1:0: Attached scsi generic sg2 type 0 Is there any other info I can provide you to help track this bug down? Cheers, -- Felipe Wilhelms Damasio TAGHOS - Tecnologia Rua Prof. Alvaro Alvim, 211 Porto Alegre - RS - (51) 3239-3180 www.taghos.com.br