As requested I tried with a kernel rom the MainlineBuilds set, Linux major 2.6.38-996-generic #201103041138 SMP Fri Mar 4 11:42:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux from linux-image-2.6.38-996-generic_2.6.38-996.201103041138_amd64.deb in the drm-next directory of http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-next/current it still fails but the error is different and actually now closer to reliably fatal and also I think now the same as my bug #717889 The test to repeat this is playing a full screen flash youtube video in chromium and then moving about in the virtual desktop in kwin - very reliable failure. Here is the full oops that is now produced: Mar 5 22:12:17 major kernel: [ 495.890854] ------------[ cut here ]------------ Mar 5 22:12:17 major kernel: [ 495.890882] kernel BUG at /home/kernel-ppa/COD/linux/drivers/gpu/drm/ttm/ttm_bo.c:272! Mar 5 22:12:17 major kernel: [ 495.890917] invalid opcode: 0000 [#1] SMP Mar 5 22:12:17 major kernel: [ 495.890939] last sysfs file: /sys/devices/system/cpu/cpu7/topology/thread_siblings Mar 5 22:12:17 major kernel: [ 495.890971] CPU 1 Mar 5 22:12:17 major kernel: [ 495.890981] Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT binfmt_misc xt_CHECKSUM iptable_mangle xt_tcpudp iptable_filter ip_tables x_tables bridge stp kvm_intel kvm dm_crypt snd_hda_codec_hdmi snd_hda_codec_via snd_hda_intel snd_seq_midi snd_hda_codec snd_rawmidi snd_hwdep snd_seq_midi_event snd_seq snd_pcm snd_seq_device snd_timer snd ppdev soundcore parport_pc snd_page_alloc lp parport radeon usbhid usb_storage ttm hid firewire_ohci drm_kms_helper uas drm firewire_core r8169 pata_via crc_itu_t i2c_algo_bit configfs Mar 5 22:12:17 major kernel: [ 495.891289] Mar 5 22:12:17 major kernel: [ 495.893682] Pid: 42, comm: kworker/1:1 Not tainted 2.6.38-996-generic #201103041138 P55M Pro/To Be Filled By O.E.M. Mar 5 22:12:17 major kernel: [ 495.896183] RIP: 0010:[] [] ttm_bo_ref_bug+0x9/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 495.898561] RSP: 0000:ffff8802277ebd90 EFLAGS: 00010202 Mar 5 22:12:17 major kernel: [ 495.900903] RAX: ffffffffa00f6801 RBX: 0000000000000000 RCX: ffff880222bb3120 Mar 5 22:12:17 major kernel: [ 495.903223] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880222bb308c Mar 5 22:12:17 major kernel: [ 495.905545] RBP: ffff8802277ebd90 R08: 0000000000000000 R09: 0000000000000000 Mar 5 22:12:17 major kernel: [ 495.907870] R10: ffff8800c7453b58 R11: 0000000000000000 R12: ffff880222bb308c Mar 5 22:12:17 major kernel: [ 495.910371] R13: ffffffffa00f3d80 R14: ffff880222bb3048 R15: 0000000000000000 Mar 5 22:12:17 major kernel: [ 495.912659] FS: 0000000000000000(0000) GS:ffff8800c7440000(0000) knlGS:0000000000000000 Mar 5 22:12:17 major kernel: [ 495.914975] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Mar 5 22:12:17 major kernel: [ 495.917310] CR2: 00000000f0969000 CR3: 00000001dc19a000 CR4: 00000000000006e0 Mar 5 22:12:17 major kernel: [ 495.919642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Mar 5 22:12:17 major kernel: [ 495.921973] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Mar 5 22:12:17 major kernel: [ 495.924274] Process kworker/1:1 (pid: 42, threadinfo ffff8802277ea000, task ffff8802277bc440) Mar 5 22:12:17 major kernel: [ 495.926774] Stack: Mar 5 22:12:17 major kernel: [ 495.929067] ffff8802277ebdc0 ffffffff812d31be 0000000000000001 0000000000000000 Mar 5 22:12:17 major kernel: [ 495.931384] ffff880222b1a208 0000000000000000 ffff8802277ebdd0 ffffffffa00f5048 Mar 5 22:12:17 major kernel: [ 495.933688] ffff8802277ebe10 ffffffffa00f67c8 01ff8802277ebe10 ffff880222bb3000 Mar 5 22:12:17 major kernel: [ 495.936003] Call Trace: Mar 5 22:12:17 major kernel: [ 495.938310] [] kref_sub+0x3e/0x80 Mar 5 22:12:17 major kernel: [ 495.940583] [] ttm_bo_list_ref_sub+0x28/0x30 [ttm] Mar 5 22:12:17 major kernel: [ 495.942967] [] ttm_bo_reserve+0x88/0xa0 [ttm] Mar 5 22:12:17 major kernel: [ 495.945209] [] radeon_unpin_work_func+0x28/0xb0 [radeon] Mar 5 22:12:17 major kernel: [ 495.947398] [] process_one_work+0x10e/0x390 Mar 5 22:12:17 major kernel: [ 495.949673] [] ? radeon_unpin_work_func+0x0/0xb0 [radeon] Mar 5 22:12:17 major kernel: [ 495.951872] [] worker_thread+0xdd/0x260 Mar 5 22:12:17 major kernel: [ 495.954094] [] ? worker_thread+0x0/0x260 Mar 5 22:12:17 major kernel: [ 495.956341] [] kthread+0x97/0xa0 Mar 5 22:12:17 major kernel: [ 495.958735] [] kernel_thread_helper+0x4/0x10 Mar 5 22:12:17 major kernel: [ 495.958738] [] ? kthread+0x0/0xa0 Mar 5 22:12:17 major kernel: [ 495.958740] [] ? kernel_thread_helper+0x0/0x10 Mar 5 22:12:17 major kernel: [ 495.958741] Code: 48 89 10 48 89 8f e0 00 00 00 48 89 8f d8 00 00 00 c9 89 f0 c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 0f 1f 44 00 00 <0f> 0b eb fe 0f 1f 00 55 48 89 e5 0f 1f 44 00 00 48 83 3e 00 48 Mar 5 22:12:17 major kernel: [ 495.958754] RIP [] ttm_bo_ref_bug+0x9/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 495.958761] RSP Mar 5 22:12:17 major kernel: [ 495.970338] ---[ end trace eb6ea5ab08ebf6f9 ]--- Mar 5 22:12:17 major kernel: [ 495.971011] BUG: unable to handle kernel paging request at fffffffffffffff8 Mar 5 22:12:17 major kernel: [ 495.973499] IP: [] kthread_data+0x10/0x20 Mar 5 22:12:17 major kernel: [ 495.976059] PGD 1a05067 PUD 1a06067 PMD 0 Mar 5 22:12:17 major kernel: [ 495.978440] Oops: 0000 [#2] SMP Mar 5 22:12:17 major kernel: [ 495.980762] last sysfs file: /sys/devices/system/cpu/cpu7/topology/thread_siblings Mar 5 22:12:17 major kernel: [ 495.983104] CPU 1 Mar 5 22:12:17 major kernel: [ 495.983112] Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT binfmt_misc xt_CHECKSUM iptable_mangle xt_tcpudp iptable_filter ip_tables x_tables bridge stp kvm_intel kvm dm_crypt snd_hda_codec_hdmi snd_hda_codec_via snd_hda_intel snd_seq_midi snd_hda_codec snd_rawmidi snd_hwdep snd_seq_midi_event snd_seq snd_pcm snd_seq_device snd_timer snd ppdev soundcore parport_pc snd_page_alloc lp parport radeon usbhid usb_storage ttm hid firewire_ohci drm_kms_helper uas drm firewire_core r8169 pata_via crc_itu_t i2c_algo_bit configfs Mar 5 22:12:17 major kernel: [ 495.993045] Mar 5 22:12:17 major kernel: [ 495.995587] Pid: 42, comm: kworker/1:1 Tainted: G D 2.6.38-996-generic #201103041138 P55M Pro/To Be Filled By O.E.M. Mar 5 22:12:17 major kernel: [ 495.998137] RIP: 0010:[] [] kthread_data+0x10/0x20 Mar 5 22:12:17 major kernel: [ 496.000687] RSP: 0018:ffff8802277eb9a8 EFLAGS: 00010096 Mar 5 22:12:17 major kernel: [ 496.003225] RAX: 0000000000000000 RBX: ffff8802277bc440 RCX: ffff8802277ebb28 Mar 5 22:12:17 major kernel: [ 496.005892] RDX: ffff8802277bc440 RSI: 0000000000000001 RDI: ffff8802277bc440 Mar 5 22:12:17 major kernel: [ 496.008436] RBP: ffff8802277eb9a8 R08: ffff8800c7456f60 R09: ffff88022762b8a8 Mar 5 22:12:17 major kernel: [ 496.010907] R10: ffff88022762b898 R11: 0000000000000001 R12: 0000000000000001 Mar 5 22:12:17 major kernel: [ 496.013390] R13: 0000000000000001 R14: ffff8800c7453ac0 R15: 00007ffffffff000 Mar 5 22:12:17 major kernel: [ 496.015887] FS: 0000000000000000(0000) GS:ffff8800c7440000(0000) knlGS:0000000000000000 Mar 5 22:12:17 major kernel: [ 496.018383] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Mar 5 22:12:17 major kernel: [ 496.020860] CR2: fffffffffffffff8 CR3: 00000001dc19a000 CR4: 00000000000006e0 Mar 5 22:12:17 major kernel: [ 496.023477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Mar 5 22:12:17 major kernel: [ 496.025936] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Mar 5 22:12:17 major kernel: [ 496.028369] Process kworker/1:1 (pid: 42, threadinfo ffff8802277ea000, task ffff8802277bc440) Mar 5 22:12:17 major kernel: [ 496.030832] Stack: Mar 5 22:12:17 major kernel: [ 496.033291] ffff8802277eb9d8 ffffffff8107f89a ffff8802277eba48 ffff8802277bc440 Mar 5 22:12:17 major kernel: [ 496.035764] ffff8802277bc7e0 0000000000000001 ffff8802277ebb28 ffffffff815b11e9 Mar 5 22:12:17 major kernel: [ 496.038401] ffff880222f55800 ffff8802277ebfd8 ffff8802277ebb28 0000000000013ac0 Mar 5 22:12:17 major kernel: [ 496.040860] Call Trace: Mar 5 22:12:17 major kernel: [ 496.043305] [] wq_worker_sleeping+0x1a/0x90 Mar 5 22:12:17 major kernel: [ 496.045791] [] schedule+0x549/0x790 Mar 5 22:12:17 major kernel: [ 496.048146] [] ? cfq_cic_free+0x19/0x20 Mar 5 22:12:17 major kernel: [ 496.050423] [] ? cic_free_func+0x7a/0x90 Mar 5 22:12:17 major kernel: [ 496.052633] [] ? cic_free_func+0x0/0x90 Mar 5 22:12:17 major kernel: [ 496.054976] [] ? __call_for_each_cic+0x34/0x50 Mar 5 22:12:17 major kernel: [ 496.057143] [] ? put_io_context+0x4d/0x60 Mar 5 22:12:17 major kernel: [ 496.059273] [] do_exit+0x2c2/0x3f0 Mar 5 22:12:17 major kernel: [ 496.061397] [] oops_end+0xf3/0x100 Mar 5 22:12:17 major kernel: [ 496.063503] [] die+0x5b/0x90 Mar 5 22:12:17 major kernel: [ 496.065648] [] do_trap+0x140/0x160 Mar 5 22:12:17 major kernel: [ 496.067779] [] ? ttm_bo_ref_bug+0x0/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 496.070047] [] do_invalid_op+0x95/0xb0 Mar 5 22:12:17 major kernel: [ 496.072160] [] ? ttm_bo_ref_bug+0x9/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 496.072163] [] ? account_entity_dequeue+0x7f/0xb0 Mar 5 22:12:17 major kernel: [ 496.072165] [] ? rb_erase+0xbf/0x140 Mar 5 22:12:17 major kernel: [ 496.072167] [] invalid_op+0x1b/0x20 Mar 5 22:12:17 major kernel: [ 496.072173] [] ? ttm_bo_ref_bug+0x0/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 496.072177] [] ? ttm_bo_global_show+0x21/0x30 [ttm] Mar 5 22:12:17 major kernel: [ 496.072181] [] ? ttm_bo_ref_bug+0x9/0x10 [ttm] Mar 5 22:12:17 major kernel: [ 496.072184] [] kref_sub+0x3e/0x80 Mar 5 22:12:17 major kernel: [ 496.072188] [] ttm_bo_list_ref_sub+0x28/0x30 [ttm] Mar 5 22:12:17 major kernel: [ 496.072192] [] ttm_bo_reserve+0x88/0xa0 [ttm] Mar 5 22:12:17 major kernel: [ 496.072206] [] radeon_unpin_work_func+0x28/0xb0 [radeon] Mar 5 22:12:17 major kernel: [ 496.072209] [] process_one_work+0x10e/0x390 Mar 5 22:12:17 major kernel: [ 496.072221] [] ? radeon_unpin_work_func+0x0/0xb0 [radeon] Mar 5 22:12:17 major kernel: [ 496.072223] [] worker_thread+0xdd/0x260 Mar 5 22:12:17 major kernel: [ 496.072225] [] ? worker_thread+0x0/0x260 Mar 5 22:12:17 major kernel: [ 496.072227] [] kthread+0x97/0xa0 Mar 5 22:12:17 major kernel: [ 496.072229] [] kernel_thread_helper+0x4/0x10 Mar 5 22:12:17 major kernel: [ 496.072231] [] ? kthread+0x0/0xa0 Mar 5 22:12:17 major kernel: [ 496.072233] [] ? kernel_thread_helper+0x0/0x10 Mar 5 22:12:17 major kernel: [ 496.072234] Code: 1f 44 00 00 65 48 8b 04 25 40 cc 00 00 48 8b 80 48 03 00 00 8b 40 f0 c9 c3 66 90 55 48 89 e5 0f 1f 44 00 00 48 8b 87 48 03 00 00 <48> 8b 40 f8 c9 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 0f Mar 5 22:12:17 major kernel: [ 496.072246] RIP [] kthread_data+0x10/0x20 Mar 5 22:12:17 major kernel: [ 496.072248] RSP Mar 5 22:12:17 major kernel: [ 496.072249] CR2: fffffffffffffff8 Mar 5 22:12:17 major kernel: [ 496.072250] ---[ end trace eb6ea5ab08ebf6fa ]--- Mar 5 22:12:17 major kernel: [ 496.072251] Fixing recursive fault but reboot is needed! root@major:/home/dg#