Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757814Ab2F0R6L (ORCPT ); Wed, 27 Jun 2012 13:58:11 -0400 Received: from smtp.witbe.net ([81.88.96.48]:60313 "EHLO smtp.witbe.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753225Ab2F0R6K (ORCPT ); Wed, 27 Jun 2012 13:58:10 -0400 Date: Wed, 27 Jun 2012 19:58:08 +0200 From: Paul Rolland To: Linux Kernel Mailing List Cc: Paul Rolland Subject: 3.5.0-rc3 - Issue with CFQ and cgroup Message-ID: <20120627195808.31714295@tux.DEF.witbe.net> Organization: AS2917.net X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.7; x86_64-unknown-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2173 Lines: 67 Hello, When I first booted my 3.5.0-rc3 config, I've some : Default I/O scheduler not found. Using noop. which surprised me. so, after the boot completed, I had a look at the system messages, and found : ... io scheduler noop registered io scheduler deadline registered ------------[ cut here ]------------ WARNING: at block/blk-cgroup.c:867 blkcg_policy_register+0xb5/0xc0() Hardware name: Vostro 1520 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.5.0-rc3 #1 Call Trace: [] warn_slowpath_common+0x7a/0xb0 [] ? deadline_init+0x12/0x12 [] warn_slowpath_null+0x15/0x20 [] blkcg_policy_register+0xb5/0xc0 [] cfq_init+0x42/0x9f [] do_one_initcall+0x3a/0x160 [] kernel_init+0x137/0x1bb [] ? do_early_param+0x87/0x87 [] kernel_thread_helper+0x4/0x10 [] ? start_kernel+0x3b2/0x3b2 [] ? gs_change+0xb/0xb ---[ end trace 82bc55f036371117 ]--- So, at the time cfq should have registered, something went wrong. It looks that this comes from my config defining CFQ, CGROUP but no CFQ_CGROUP_IOSCHED. ... CONFIG_CGROUPS=y CONFIG_IOSCHED_CFQ=y # CONFIG_CFQ_GROUP_IOSCHED is not set ... as the code is : static struct blkcg_policy blkcg_policy_cfq __maybe_unused; ... #ifdef CONFIG_CFQ_GROUP_IOSCHED static struct blkcg_policy blkcg_policy_cfq = { .pd_size = sizeof(struct cfq_group), .cftypes = cfq_blkcg_files, .pd_init_fn = cfq_pd_init, .pd_reset_stats_fn = cfq_pd_reset_stats, }; #endif ... static int __init cfq_init(void) { ... ret = blkcg_policy_register(&blkcg_policy_cfq); Not sure what's the best fix is... Could someone shed some light on this ? Paul PS: Just checked 3.5-rc4, source code there is the same. -- 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/