Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762463AbXLQWpb (ORCPT ); Mon, 17 Dec 2007 17:45:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936843AbXLQWoe (ORCPT ); Mon, 17 Dec 2007 17:44:34 -0500 Received: from turing-police.cc.vt.edu ([128.173.14.107]:49082 "EHLO turing-police.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934024AbXLQWod (ORCPT ); Mon, 17 Dec 2007 17:44:33 -0500 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: 2.6.24-rc5-mm1 - wonky disk cache and CDROM behavior... In-Reply-To: Your message of "Thu, 13 Dec 2007 02:40:50 PST." <20071213024050.7d6e5f3e.akpm@linux-foundation.org> From: Valdis.Kletnieks@vt.edu References: <20071213024050.7d6e5f3e.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1197931451_2751P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Mon, 17 Dec 2007 17:44:11 -0500 Message-ID: <30457.1197931451@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2841 Lines: 56 --==_Exmh_1197931451_2751P Content-Type: text/plain; charset="us-ascii" Content-Id: <30445.1197931442.1@turing-police.cc.vt.edu> On Thu, 13 Dec 2007 02:40:50 PST, Andrew Morton said: > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.24-rc5/2.6.24-rc5-mm1/ OK, so I'm trying to 'dd' a CD and the drive on the laptop is having issues reading the disk. I try it once, and get an I/O error about 117M in - dd reports 1.7M/sec. I try it again, and it reports it died at the same exact place, but in about 2 seconds flat, and reports 91M/sec transfer. OK, that's *weird*, I didn't think that blocks read from /dev/cdrom would get cached, but OK. So I try the obviously stupid thing: # echo 1 >| /proc/sys/vm/drop_caches Alas, that hangs gloriously - 'echo t > /proc/sysrq-trigger' tells me: Dec 17 17:30:02 turing-police kernel: [20235.823201] bash D 0000000000000001 5288 15123 15085 Dec 17 17:30:02 turing-police kernel: [20235.823206] ffff81007ba7de28 0000000000000086 0000000000000000 0000000000000000 Dec 17 17:30:02 turing-police kernel: [20235.823210] ffff81007bbd9000 ffff81007d70e000 ffff81007bbd9248 00000001019e3e48 Dec 17 17:30:02 turing-police kernel: [20235.823214] ffffe20000f36028 ffffe200012b9978 ffffe20000eece48 ffffe20001164188 Dec 17 17:30:02 turing-police kernel: [20235.823218] Call Trace: Dec 17 17:30:02 turing-police kernel: [20235.823224] [] __down_read+0x87/0xa1 Dec 17 17:30:02 turing-police kernel: [20235.823229] [] down_read+0x9/0xe Dec 17 17:30:02 turing-police kernel: [20235.823232] [] drop_pagecache+0x3a/0x8c Dec 17 17:30:02 turing-police kernel: [20235.823235] [] drop_caches_sysctl_handler+0x22/0x38 Dec 17 17:30:02 turing-police kernel: [20235.823239] [] proc_sys_write+0x7e/0xa6 Dec 17 17:30:02 turing-police kernel: [20235.823244] [] vfs_write+0xc7/0x170 Dec 17 17:30:02 turing-police kernel: [20235.823248] [] sys_write+0x47/0x70 Dec 17 17:30:02 turing-police kernel: [20235.823251] [] tracesys+0xdc/0xe1 Yowza. And no, I don't dare to try to reproduce it until Thursday at the earliest, I need a mostly-stable machine the next 2 days. ;) --==_Exmh_1197931451_2751P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFHZvu7cC3lWbTT17ARAnqSAKDFsDq1qLSXqFrwf9vrgc3YkdTqGACguifb HMHMnm5I+DO6qQz9tvWExuU= =yYVA -----END PGP SIGNATURE----- --==_Exmh_1197931451_2751P-- -- 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/