Hi, I'm also seeing this bug daily in Fedora 12. It seems to duplicate the following bugs reported to LKML and Ubuntu: http://lkml.org/lkml/2009/1/11/70 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/276476 Note that LKML seems to imply that a patch was incorporated in 2.6.29 while feedback from Ubuntu is that the bug is still present in 2.6.31. My seeing the bug would seem to confirm that the issue is also still unfixed and present in fedora 12. Here is some sample output: Jan 27 00:55:29 hyperion kernel: INFO: task firefox:2624 blocked for more than 120 seconds. Jan 27 00:55:29 hyperion kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jan 27 00:55:29 hyperion kernel: firefox D 0000000000000002 0 2624 2062 0x00000000 Jan 27 00:55:29 hyperion kernel: ffff88008f125528 0000000000000086 ffff88008f1254a8 ffff880000000000 Jan 27 00:55:29 hyperion kernel: ffff88008f125498 ffffffff8104039a ffff8801fdce2f38 ffff880028066670 Jan 27 00:55:29 hyperion kernel: ffff8801fdce32c8 000000000000f8f0 ffff8801fdce32c8 0000000000015600 Jan 27 00:55:29 hyperion kernel: Call Trace: Jan 27 00:55:29 hyperion kernel: [] ? account_group_exec_runtime+0x30/0x43 Jan 27 00:55:29 hyperion kernel: [] ? clocksource_read+0xf/0x11 Jan 27 00:55:29 hyperion kernel: [] ? ktime_get_ts+0x4e/0x53 Jan 27 00:55:29 hyperion kernel: [] ? sync_page+0x0/0x4a Jan 27 00:55:29 hyperion kernel: [] io_schedule+0x31/0x42 Jan 27 00:55:29 hyperion kernel: [] sync_page+0x46/0x4a Jan 27 00:55:29 hyperion kernel: [] __wait_on_bit+0x48/0x7b Jan 27 00:55:29 hyperion kernel: [] ? thread_return+0x4e/0xc3 Jan 27 00:55:29 hyperion kernel: [] wait_on_page_bit+0x72/0x79 Jan 27 00:55:29 hyperion kernel: [] ? wake_bit_function+0x0/0x33 Jan 27 00:55:29 hyperion kernel: [] ? page_evictable+0x17/0x81 Jan 27 00:55:29 hyperion kernel: [] shrink_page_list+0x11d/0x5e0 Jan 27 00:55:29 hyperion kernel: [] ? delayacct_end+0x82/0x8d Jan 27 00:55:29 hyperion kernel: [] ? __delayacct_blkio_end+0x3e/0x40 Jan 27 00:55:29 hyperion kernel: [] ? delayacct_blkio_end+0x21/0x41 Jan 27 00:55:29 hyperion kernel: [] ? io_schedule_timeout+0x4d/0x58 Jan 27 00:55:29 hyperion kernel: [] ? congestion_wait+0x80/0x8f Jan 27 00:55:29 hyperion kernel: [] ? autoremove_wake_function+0x0/0x39 Jan 27 00:55:29 hyperion kernel: [] shrink_list+0x3b2/0x64a Jan 27 00:55:29 hyperion kernel: [] ? determine_dirtyable_memory+0x1a/0x2d Jan 27 00:55:29 hyperion kernel: [] ? get_dirty_limits+0x27/0x24f Jan 27 00:55:29 hyperion kernel: [] shrink_zone+0x2a0/0x32c Jan 27 00:55:29 hyperion kernel: [] do_try_to_free_pages+0x1ea/0x353 Jan 27 00:55:29 hyperion kernel: [] try_to_free_pages+0x6e/0x70 Jan 27 00:55:29 hyperion kernel: [] ? isolate_pages_global+0x0/0x229 Jan 27 00:55:29 hyperion kernel: [] __alloc_pages_nodemask+0x3d7/0x5b0 Jan 27 00:55:29 hyperion kernel: [] alloc_pages_current+0x95/0x9e Jan 27 00:55:29 hyperion kernel: [] alloc_slab_page+0x1b/0x28 Jan 27 00:55:29 hyperion kernel: [] new_slab+0x54/0x1d3 Jan 27 00:55:29 hyperion kernel: [] __slab_alloc+0x1f1/0x3a1 Jan 27 00:55:29 hyperion kernel: [] ? snd_ctl_ioctl+0x327/0x783 [snd] Jan 27 00:55:29 hyperion kernel: [] __kmalloc_track_caller+0x104/0x158 Jan 27 00:55:29 hyperion kernel: [] ? snd_ctl_ioctl+0x327/0x783 [snd] Jan 27 00:55:29 hyperion kernel: [] memdup_user+0x29/0x68 Jan 27 00:55:29 hyperion kernel: [] snd_ctl_ioctl+0x327/0x783 [snd] Jan 27 00:55:29 hyperion kernel: [] ? avc_has_perm+0x5c/0x6e Jan 27 00:55:29 hyperion kernel: [] vfs_ioctl+0x22/0x87 Jan 27 00:55:29 hyperion kernel: [] ? finish_task_switch+0xc3/0xe6 Jan 27 00:55:29 hyperion kernel: [] do_vfs_ioctl+0x47b/0x4c1 Jan 27 00:55:29 hyperion kernel: [] sys_ioctl+0x56/0x79 Jan 27 00:55:29 hyperion kernel: [] system_call_fastpath+0x16/0x1b Note that there appears to be some sound system calls above in the trace, so I will look into switching sound card drivers for time being. I am currently using the following modules: [root@hyperion ~]# lsmod Module Size Used by rfcomm 71504 4 sco 19972 2 bridge 54112 0 stp 2724 1 bridge llc 6400 2 bridge,stp bnep 19472 2 l2cap 38992 16 rfcomm,bnep nfsd 277328 9 exportfs 4544 1 nfsd nfs 279952 1 lockd 71572 2 nfsd,nfs fscache 38856 1 nfs nfs_acl 3152 2 nfsd,nfs auth_rpcgss 41552 2 nfsd,nfs vmnet 45756 3 ppdev 10040 0 parport_pc 27640 0 parport 34320 2 ppdev,parport_pc vmblock 15032 1 vsock 43680 0 vmci 54936 1 vsock vmmon 78252 0 sunrpc 191912 16 nfsd,nfs,lockd,nfs_acl,auth_rpcgss ipv6 298928 62 p4_clockmod 6148 0 freq_table 4864 1 p4_clockmod speedstep_lib 5712 1 p4_clockmod uvcvideo 58972 0 videodev 36160 1 uvcvideo v4l1_compat 13892 2 uvcvideo,videodev snd_usb_audio 97200 2 v4l2_compat_ioctl32 10736 1 videodev snd_usb_lib 17664 1 snd_usb_audio snd_rawmidi 24032 1 snd_usb_lib snd_seq_device 7620 1 snd_rawmidi dm_multipath 17304 0 tcp_bic 4692 22 uinput 9248 0 btusb 18756 2 bluetooth 94884 12 rfcomm,sco,bnep,l2cap,btusb rfkill 20488 2 bluetooth nvidia 9624568 38 snd_hda_codec_realtek 281380 1 snd_hda_intel 30360 2 snd_hda_codec 72832 2 snd_hda_codec_realtek,snd_hda_intel e1000 115460 0 firewire_ohci 23332 0 snd_hwdep 9224 2 snd_usb_audio,snd_hda_codec snd_pcm 83144 3 snd_usb_audio,snd_hda_intel,snd_hda_codec iTCO_wdt 13008 0 i2c_i801 12800 0 iTCO_vendor_support 3588 1 iTCO_wdt firewire_core 47880 1 firewire_ohci asus_atk0110 12560 0 serio_raw 6644 0 shpchp 34636 0 snd_timer 22608 1 snd_pcm i2c_core 28976 3 videodev,nvidia,i2c_i801 joydev 11984 0 snd 67592 18 snd_usb_audio,snd_usb_lib,snd_rawmidi,snd_seq_device,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_timer crc_itu_t 2080 1 firewire_core soundcore 7328 1 snd snd_page_alloc 9568 2 snd_hda_intel,snd_pcm usb_storage 60496 0 [root@hyperion ~]# uname -a Linux hyperion.deploylinux.net 2.6.31.12-174.2.3.fc12.x86_64 #1 SMP Mon Jan 18 19:52:07 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux