From: Sedat Dilek Subject: Re: jbd2: don't wake kjournald unnecessarily Date: Sun, 20 Jan 2013 01:35:07 +0100 Message-ID: References:

Reply-To: sedat.dilek@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Jan Kara , linux-fsdevel , Ext4 Developers List , "Theodore Ts'o" , LKML , linux-next To: Eric Sandeen Return-path: Received: from mail-qc0-f171.google.com ([209.85.216.171]:33472 "EHLO mail-qc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160Ab3ATAfJ (ORCPT ); Sat, 19 Jan 2013 19:35:09 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Jan 20, 2013 at 1:06 AM, Sedat Dilek wrote: > On Sun, Jan 20, 2013 at 12:44 AM, Sedat Dilek wrote: >> Hi, >> >> I and some others hit a similiar problem in Linux-Next >> (next-20130118), please see [1] and [2]. >> >> [3] has a interim analyze of my problems. >> >> After suspecting the problem was caused by TTY-NEXT, it turned out to >> be a JBD2 problem finally. >> The freezer/pm_test was helpful to hit the issue (Thanks Rafael for the hint!). >> >> So, the issue has two faces: TTY and JBD2. >> [4] gives a list and URLs of the patches I had to apply to have a >> clean system again. >> >> After applying the two TTY patches (without Eric's JBD2-fix!) the >> call-trace after freezer/pm_test looked like this; >> >> [ 433.527986] PM: Syncing filesystems ... done. >> [ 433.843761] PM: Preparing system for mem sleep >> [ 436.306002] Freezing user space processes ... >> [ 456.304956] Freezing of tasks failed after 20.01 seconds (1 tasks >> refusing to freeze, wq_busy=0): >> [ 456.305060] Cache I/O D ffffffff8180d780 0 2132 1 0x00000004 >> [ 456.305065] ffff88007b9dfe18 0000000000000046 ffff88007b9dfdc8 >> 0000000300000001 >> [ 456.305069] ffff880097e21720 ffff88007b9dffd8 ffff88007b9dffd8 >> ffff88007b9dffd8 >> [ 456.305072] ffff880119b32e40 ffff880097e21720 ffff88007b9dfe28 >> ffff880118077800 >> [ 456.305076] Call Trace: >> [ 456.305085] [] schedule+0x29/0x70 >> [ 456.305089] [] jbd2_log_wait_commit+0xcd/0x1a0 >> [ 456.305094] [] ? add_wait_queue+0x60/0x60 >> [ 456.305098] [] ext4_sync_file+0x205/0x380 >> [ 456.305103] [] do_fsync+0x5d/0x90 >> [ 456.305108] [] ? sys_write+0x6b/0xa0 >> [ 456.305111] [] sys_fsync+0x10/0x20 >> [ 456.305114] [] system_call_fastpath+0x1a/0x1f >> [ 456.305122] >> [ 456.305124] Restarting tasks ... done. >> [ 456.315056] video LNXVIDEO:00: Restoring backlight state >> >> After applying Eric's patch [5], I could not hit the call-trace again. >> NOTE: The patch is from December 2012 and is not shipped in latest Linux-Next. >> >> The attached testcase script was helpful to force the call-trace. >> I have run 50 loops of it w/o an issue! >> >> Feel free to add a Reported-by/Tested-by. >> ( The issue kept me busy for the last days. ) >> >> Regards, >> - Sedat - >> >> [1] http://marc.info/?t=135283664600002&r=1&w=2 >> [2] http://marc.info/?t=135862023700004&r=1&w=2 >> [3] http://marc.info/?l=linux-kernel&m=135862010419101&w=2 >> [4] http://marc.info/?l=linux-next&m=135863550923093&w=2 >> [5] http://patchwork.ozlabs.org/patch/207237/ > > Hi all, > > this is really ugly... I could cry! > > GRRR, I have hit the original issue again while running my testcase script! > > [ 363.831226] PM: Syncing filesystems ... done. > [ 363.988855] PM: Preparing system for mem sleep > [ 369.032965] Freezing user space processes ... (elapsed 0.11 seconds) done. > [ 369.145792] Freezing remaining freezable tasks ... > [ 389.137643] Freezing of tasks failed after 20.01 seconds (1 tasks > refusing to freeze, wq_busy=0): > [ 389.137760] jbd2/loop0-8 D ffffffff8180d780 0 295 2 0x00000000 > [ 389.137769] ffff8801181dfb68 0000000000000046 ffff880117de5c80 > 0000000000000001 > [ 389.137778] ffff880117de5c80 ffff8801181dffd8 ffff8801181dffd8 > ffff8801181dffd8 > [ 389.137784] ffffffff81c15440 ffff880117de5c80 ffff8801181dfb68 > ffff88011fa14738 > [ 389.137791] Call Trace: > [ 389.137810] [] ? __wait_on_buffer+0x30/0x30 > [ 389.137819] [] schedule+0x29/0x70 > [ 389.137825] [] io_schedule+0x8f/0xd0 > [ 389.137832] [] sleep_on_buffer+0xe/0x20 > [ 389.137842] [] __wait_on_bit+0x5f/0x90 > [ 389.137849] [] ? submit_bh+0x121/0x1e0 > [ 389.137856] [] ? __wait_on_buffer+0x30/0x30 > [ 389.137864] [] out_of_line_wait_on_bit+0x7c/0x90 > [ 389.137873] [] ? autoremove_wake_function+0x40/0x40 > [ 389.137879] [] __wait_on_buffer+0x2e/0x30 > [ 389.137891] [] > jbd2_journal_commit_transaction+0x18cc/0x1d60 > [ 389.137899] [] ? _raw_spin_lock_irqsave+0x2e/0x40 > [ 389.137908] [] ? try_to_del_timer_sync+0x4f/0x70 > [ 389.137915] [] kjournald2+0xd6/0x3e0 > [ 389.137921] [] ? add_wait_queue+0x60/0x60 > [ 389.137926] [] ? commit_timeout+0x10/0x10 > [ 389.137932] [] kthread+0xc0/0xd0 > [ 389.137939] [] ? flush_kthread_worker+0xb0/0xb0 > [ 389.137946] [] ret_from_fork+0x7c/0xb0 > [ 389.137951] [] ? flush_kthread_worker+0xb0/0xb0 > [ 389.138017] > [ 389.138021] Restarting kernel threads ... done. > [ 389.138173] Restarting tasks ... done. > [ 389.147980] video LNXVIDEO:00: Restoring backlight state > > I suspect there are still issues in JBD2 (BTW I run here EXT4FS). > > [ 389.137643] Freezing of tasks failed after 20.01 seconds (1 tasks > refusing to freeze, wq_busy=0): > [ 389.137760] jbd2/loop0-8 D ffffffff8180d780 0 295 2 0x00000000 > > Have a good night, /me -> watching TV! > > - Sedat - Man, what a NONSENSE I am telling... The mentioned so-called fix is already in next-20130118, shame on me! commit 7e2fb2d7e6a3094473f101ae33dd6431ae6d2ed1 "jbd: don't wake kjournald unnecessarily" - Sedat - [1] http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=7e2fb2d7e6a3094473f101ae33dd6431ae6d2ed1