Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753171Ab0AJUFy (ORCPT ); Sun, 10 Jan 2010 15:05:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751584Ab0AJUFy (ORCPT ); Sun, 10 Jan 2010 15:05:54 -0500 Received: from mail.fem.tu-ilmenau.de ([141.24.101.79]:32779 "EHLO mail.fem.tu-ilmenau.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751535Ab0AJUFx (ORCPT ); Sun, 10 Jan 2010 15:05:53 -0500 From: Johannes Hirte To: Chris Mason Subject: task imap:2958 blocked for more than 120 seconds Date: Sun, 10 Jan 2010 21:05:46 +0100 User-Agent: KMail/1.13.0 (Linux/2.6.33-rc2-00302-gc5974b8-dirty; KDE/4.3.90; x86_64; ; ) Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201001102105.47192.johannes.hirte@fem.tu-ilmenau.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10476 Lines: 91 I've observed this hanging task now several times. Not sure when this started, but 2.6.32 is affected too, IIRC. I don't have a test pattern for this. Dovecot imap triggers this from time to time. I've enabled CONFIG_DETECT_HUNG_TASK now and got this two tasks which hang: INFO: task imap:2958 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. imap D 0000000000000000 0 2958 2653 0x00000000 ffff88008caf5a28 0000000000000046 0000000000000000 ffffffff810544cf ffff88008caf5998 0000000000000001 ffff88008caf5fd8 ffff88008caf9530 000000000000de78 00000000001d2700 00000000001d2700 ffff88008caf9530 Call Trace: [] ? trace_hardirqs_off+0xd/0xf [] ? trace_hardirqs_on_caller+0x10c/0x130 [] ? sync_page+0x0/0x48 [] io_schedule+0x38/0x4d [] sync_page+0x44/0x48 [] __wait_on_bit_lock+0x41/0x8a [] __lock_page+0x61/0x68 [] ? wake_bit_function+0x0/0x2e [] filemap_fault+0xea/0x345 [] __do_fault+0x50/0x3d3 [] handle_mm_fault+0x32f/0x65d [] ? do_page_fault+0xf4/0x26f [] ? __down_read_trylock+0x46/0x4e [] ? down_read_trylock+0x3f/0x49 [] ? do_page_fault+0xf4/0x26f [] do_page_fault+0x257/0x26f [] page_fault+0x1f/0x30 [] ? might_fault+0x57/0xa7 [] ? btrfs_copy_from_user+0x4f/0x113 [] ? btrfs_copy_from_user+0xde/0x113 [] btrfs_file_write+0x439/0x6fe [] vfs_write+0xad/0x14e [] ? trace_hardirqs_on_caller+0x10c/0x130 [] sys_pwrite64+0x55/0x74 [] system_call_fastpath+0x16/0x1b 2 locks held by imap/2958: #0: (&sb->s_type->i_mutex_key#4){+.+.+.}, at: [] btrfs_file_write+0x169/0x6fe #1: (&mm->mmap_sem){++++++}, at: [] do_page_fault+0xf4/0x26f INFO: task flush-btrfs-2:2783 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-btrfs-2 D 0000000000000000 0 2783 2 0x00000000 ffff88010cdcf9d0 0000000000000046 0000000000000000 ffffffff810544cf ffff88010cdcf940 0000000000000000 ffff88010cdcffd8 ffff88010cd18290 000000000000de78 00000000001d2700 00000000001d2700 ffff88010cd18290 Call Trace: [] ? trace_hardirqs_off+0xd/0xf [] ? trace_hardirqs_on_caller+0x10c/0x130 [] ? sync_page+0x0/0x48 [] io_schedule+0x38/0x4d [] sync_page+0x44/0x48 [] __wait_on_bit_lock+0x41/0x8a [] ? find_get_pages_tag+0x0/0x130 [] __lock_page+0x61/0x68 [] ? wake_bit_function+0x0/0x2e [] T.858+0xf1/0x2cd [] ? sched_clock_cpu+0xc6/0xd4 [] ? sched_clock_local+0x1c/0x82 [] ? sched_clock_cpu+0xc6/0xd4 [] ? trace_hardirqs_off+0xd/0xf [] extent_writepages+0x3f/0x54 [] ? btrfs_get_extent+0x0/0x7ee [] btrfs_writepages+0x22/0x24 [] do_writepages+0x1f/0x28 [] writeback_single_inode+0xf1/0x2f0 [] writeback_inodes_wb+0x3a9/0x4b2 [] wb_writeback+0x12b/0x1af [] wb_do_writeback+0x17f/0x195 [] ? wb_do_writeback+0x8b/0x195 [] bdi_writeback_task+0x2b/0x84 [] ? bdi_start_fn+0x0/0xcf [] bdi_start_fn+0x71/0xcf [] ? bdi_start_fn+0x0/0xcf [] kthread+0x7a/0x82 [] kernel_thread_helper+0x4/0x10 [] ? restore_args+0x0/0x30 [] ? kthread+0x0/0x82 [] ? kernel_thread_helper+0x0/0x10 1 lock held by flush-btrfs-2/2783: #0: (&type->s_umount_key#20){++++..}, at: [] writeback_inodes_wb+0x2d4/0x4b2 regards, Johannes -- 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/