Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754295Ab0BGKum (ORCPT ); Sun, 7 Feb 2010 05:50:42 -0500 Received: from borg.medozas.de ([188.40.89.202]:59313 "EHLO borg.medozas.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932087Ab0BGKui (ORCPT ); Sun, 7 Feb 2010 05:50:38 -0500 Date: Sun, 7 Feb 2010 11:50:36 +0100 (CET) From: Jan Engelhardt To: Jens Axboe cc: Linux Kernel Mailing List Subject: Re: kswapd continuously active In-Reply-To: Message-ID: References: <20100125130627.GO13771@kernel.dk> <20100205130002.GI1025@kernel.dk> <20100205131220.GK1025@kernel.dk> User-Agent: Alpine 2.01 (LSU 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1671 Lines: 39 On Friday 2010-02-05 14:24, Jan Engelhardt wrote: >>> The ext4 filesystem is already mounted with barrier=0. If there >>> is any block-level barriers I also can turn off, what would be >>> the command? >> >>barrier=0 is enough. I do wonder why your writeback rate is that slow, >>then. The disk has write back caching enabled? > >Yes, that seems to be the case at least. In fact the box is all fluffy >when nobody runs sync(1), which is what makes it so strange. > >sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't >support DPO or FUA Here is an alternate trace that just happened. INFO: task flush-8:0:343 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-8:0 D 0000000000555930 6664 343 2 0x18000000000 Call Trace: [00000000005555f4] start_this_handle+0x324/0x4b0 [0000000000555930] jbd2_journal_start+0x94/0xc0 [000000000052ddb8] ext4_da_writepages+0x1e0/0x460 [000000000049bf30] do_writepages+0x28/0x48 [00000000004e6d58] writeback_single_inode+0xf0/0x330 [00000000004e7b24] writeback_inodes_wb+0x4c8/0x5d8 [00000000004e7da4] wb_writeback+0x170/0x1ec [00000000004e8074] wb_do_writeback+0x188/0x1a4 [00000000004e80b8] bdi_writeback_task+0x28/0xa0 [00000000004a76c8] bdi_start_fn+0x64/0xc4 [0000000000475f84] kthread+0x58/0x6c [000000000042ade0] kernel_thread+0x30/0x48 [0000000000475ee0] kthreadd+0xb8/0x104 -- 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/