From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 85CE5B7167 for ; Wed, 17 Jun 2009 20:51:50 +1000 (EST) Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com [59.145.155.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp04.in.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 93D14DDD1C for ; Wed, 17 Jun 2009 20:51:48 +1000 (EST) Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28smtp04.in.ibm.com (8.13.1/8.13.1) with ESMTP id n5HApYea027877 for ; Wed, 17 Jun 2009 16:21:34 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n5HApO8l2117668 for ; Wed, 17 Jun 2009 16:21:24 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.13.1/8.13.3) with ESMTP id n5HApNKp014592 for ; Wed, 17 Jun 2009 16:21:23 +0530 Message-ID: <4A38CAAC.4090606@in.ibm.com> Date: Wed, 17 Jun 2009 16:21:24 +0530 From: Sachin Sant MIME-Version: 1.0 To: linux-kernel Subject: [BUG] lib/kernel_lock.c:126 with cgroups regression ltp tests Content-Type: multipart/mixed; boundary="------------080808090809040803080509" Cc: linuxppc-dev@ozlabs.org, menage@google.com, Balbir Singh List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a multi-part message in MIME format. --------------080808090809040803080509 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit While executing cgroups regression tests from LTP May 2009 release on a Power6 box came across the following bug. This is with 2.6.30-git10 (300df7dc89cc276377fc020704e34875d5c473b6) ------------[ cut here ]------------ kernel BUG at lib/kernel_lock.c:126! Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=1024 NUMA pSeries Modules linked in: ipv6 fuse loop dm_mod sr_mod ehea cdrom sg ibmveth sd_mod crc_t10dif ibmvscsic scsi_transport_srp scsi_tgt scsi_mod NIP: c0000000005c6dac LR: c0000000001965ac CTR: 0000000000000006 REGS: c00000002a5d3910 TRAP: 0700 Not tainted (2.6.30-git10) MSR: 8000000000029032 CR: 82042442 XER: 00000000 TASK = c0000000407cbc20[9581] 'mount' THREAD: c00000002a5d0000 CPU: 3 <6>GPR00: 0000000000000001 c00000002a5d3b90 c000000000ef31f0 fffffffffffffff0 <6>GPR04: c0000000000f0098 c000000000799813 0000000000000000 0000000000000001 <6>GPR08: c000000000e36aa0 c0000000407cbc20 0000000000000002 c0000000407cbc20 <6>GPR12: 0000000024042424 c000000000ff2a00 00000fffed50f6fd 00000fffed506e08 <6>GPR16: 00000fffed506db8 000000001002b638 0000000000000000 0000000000000000 <6>GPR20: 00000000100329a0 00000fffed506e0c c00000003e14b870 0000000000000000 <6>GPR24: 0000000000000000 c00000002a030000 0000000000000000 0000000000000000 <6>GPR28: c00000003e14b800 fffffffffffffff0 c000000000e7aa40 c00000002a5d3b90 NIP [c0000000005c6dac] .unlock_kernel+0x20/0x78 LR [c0000000001965ac] .do_remount_sb+0x190/0x204 Call Trace: [c00000002a5d3bd0] [c00000000019659c] .do_remount_sb+0x180/0x204 [c00000002a5d3c70] [c0000000001b8210] .do_mount+0x38c/0x9fc [c00000002a5d3d60] [c0000000001b8940] .SyS_mount+0xc0/0x12c [c00000002a5d3e30] [c000000000008534] syscall_exit+0x0/0x40 Instruction dump: 383f0040 ebc1fff0 ebe1fff8 4e800020 fbc1fff0 fbe1fff8 f821ffc1 7c3f0b78 ebc2c0b8 e92d01b0 e809001e 78000fe0 <0b000000> e96d01b0 812b001c 3929ffff ---[ end trace 3bf0012ad33d52b2 ]--- Corresponding c code is : void __lockfunc unlock_kernel(void) { BUG_ON(current->lock_depth < 0); <<====== if (likely(--current->lock_depth < 0)) __unlock_kernel(); Have attached the cgroups regression test run log. Thanks -Sachin -- --------------------------------- Sachin Sant IBM Linux Technology Center India Systems and Technology Labs Bangalore, India --------------------------------- --------------080808090809040803080509 Content-Type: text/x-log; name="controller-run.log" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="controller-run.log" cgroup_regression_test 1 PASS : no kernel bug was found /ltp-full-20090531/testcases/bin/cgroup_regression_test.sh: line 102: 7036 Terminated ./fork_processes cgroup_regression_test 2 PASS : notify_on_release is inherited cgroup_regression_test 3 PASS : no kernel bug was found cgroup_regression_test 4 CONF : CONFIG_LOCKDEP is not enabled cgroup_regression_test 5 PASS : no kernel bug was found /ltp-full-20090531/testcases/bin/cgroup_regression_test.sh: line 253: 8781 Terminated sleep 100 /ltp-full-20090531/testcases/bin/cgroup_regression_test.sh: line 325: 8800 Terminated ./test_6_2 cgroup_regression_test 6 PASS : no kernel bug was found ------------[ cut here ]------------ Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=1024 NUMA pSeries Modules linked in: ipv6 fuse loop dm_mod sr_mod ehea cdrom sg ibmveth sd_mod crc_t10dif ibmvscsic scsi_transport_srp scsi_tgt scsi_mod NIP: c0000000005c6dac LR: c0000000001965ac CTR: 0000000000000006 REGS: c00000002a5d3910 TRAP: 0700 Not tainted (2.6.30-git10) MSR: 8000000000029032 CR: 82042442 XER: 00000000 TASK = c0000000407cbc20[9581] 'mount' THREAD: c00000002a5d0000 CPU: 3 <6>GPR00: 0000000000000001 c00000002a5d3b90 c000000000ef31f0 fffffffffffffff0 <6>GPR04: c0000000000f0098 c000000000799813 0000000000000000 0000000000000001 <6>GPR08: c000000000e36aa0 c0000000407cbc20 0000000000000002 c0000000407cbc20 <6>GPR12: 0000000024042424 c000000000ff2a00 00000fffed50f6fd 00000fffed506e08 <6>GPR16: 00000fffed506db8 000000001002b638 0000000000000000 0000000000000000 <6>GPR20: 00000000100329a0 00000fffed506e0c c00000003e14b870 0000000000000000 <6>GPR24: 0000000000000000 c00000002a030000 0000000000000000 0000000000000000 <6>GPR28: c00000003e14b800 fffffffffffffff0 c000000000e7aa40 c00000002a5d3b90 NIP [c0000000005c6dac] .unlock_kernel+0x20/0x78 LR [c0000000001965ac] .do_remount_sb+0x190/0x204 Call Trace: [c00000002a5d3bd0] [c00000000019659c] .do_remount_sb+0x180/0x204 [c00000002a5d3c70] [c0000000001b8210] .do_mount+0x38c/0x9fc [c00000002a5d3d60] [c0000000001b8940] .SyS_mount+0xc0/0x12c [c00000002a5d3e30] [c000000000008534] syscall_exit+0x0/0x40 Instruction dump: 383f0040 ebc1fff0 ebe1fff8 4e800020 fbc1fff0 fbe1fff8 f821ffc1 7c3f0b78 ebc2c0b8 e92d01b0 e809001e 78000fe0 <0b000000> e96d01b0 812b001c 3929ffff ---[ end trace 3bf0012ad33d52b2 ]--- /ltp-full-20090531/testcases/bin/cgroup_regression_test.sh: line 347: 9581 Trace/breakpoint trap mount -t cgroup -o remount xxx cgroup/ 2> /dev/null /ltp-full-20090531/testcases/bin/cgroup_regression_test.sh: line 363: 9579 Terminated sleep 100 < cgroup/0 Cannot create link /etc/mtab~ Perhaps there is a stale lock file? Cannot create link /etc/mtab~ Perhaps there is a stale lock file? --------------080808090809040803080509--