btrfs kernel trace, patched

May  1 08:13:20 ewzw032 kernel: [  196.718434] num_pages is 10000, blockgroup? yes
May  1 08:13:20 ewzw032 kernel: [  196.718473] block group offset=83999326208, size=167959920640
May  1 08:13:20 ewzw032 kernel: [  196.718509] ------------[ cut here ]------------
May  1 08:13:20 ewzw032 kernel: [  196.718535] WARNING: at fs/btrfs/free-space-cache.c:925 __btrfs_write_out_cache+0x9e2/0xa10 [btrfs]()
May  1 08:13:20 ewzw032 kernel: [  196.718536] Hardware name: HP Compaq dc5800 Microtower
May  1 08:13:20 ewzw032 kernel: [  196.718537] Modules linked in: arc4 md4 parport_pc ppdev rfcomm bnep bluetooth nls_utf8 cifs fscache ext2 tpm_infineon snd_hda_codec_analog coretemp kvm_intel kvm hp_wmi sparse_keymap gpio_ich snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc dm_multipath snd_seq_midi scsi_dh tpm_tis wmi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer nvidia(POF) mac_hid snd psmouse microcode serio_raw lpc_ich mei soundcore lp parport btrfs zlib_deflate libcrc32c hid_generic usbhid hid floppy e1000e usb_storage
May  1 08:13:20 ewzw032 kernel: [  196.718564] Pid: 2803, comm: sync Tainted: PF          O 3.8.0-19-lowlatency #13
May  1 08:13:20 ewzw032 kernel: [  196.718565] Call Trace:
May  1 08:13:20 ewzw032 kernel: [  196.718571]  [<ffffffff8105a8df>] warn_slowpath_common+0x7f/0xc0
May  1 08:13:20 ewzw032 kernel: [  196.718573]  [<ffffffff8105a93a>] warn_slowpath_null+0x1a/0x20
May  1 08:13:20 ewzw032 kernel: [  196.718583]  [<ffffffffa0103f52>] __btrfs_write_out_cache+0x9e2/0xa10 [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718587]  [<ffffffff81094065>] ? cpuacct_charge+0x75/0x80
May  1 08:13:20 ewzw032 kernel: [  196.718590]  [<ffffffff810145d1>] ? __switch_to+0x181/0x4d0
May  1 08:13:20 ewzw032 kernel: [  196.718601]  [<ffffffffa0104015>] btrfs_write_out_cache+0x95/0xf0 [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718610]  [<ffffffffa00b8c07>] btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718619]  [<ffffffffa012adc2>] commit_cowonly_roots+0x15a/0x22c [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718629]  [<ffffffffa00c84ec>] btrfs_commit_transaction+0x62c/0xb00 [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718632]  [<ffffffff81080070>] ? finish_wait+0x80/0x80
May  1 08:13:20 ewzw032 kernel: [  196.718635]  [<ffffffff811ca3a0>] ? fdatawait_one_bdev+0x20/0x20
May  1 08:13:20 ewzw032 kernel: [  196.718643]  [<ffffffffa009a9f2>] btrfs_sync_fs+0x62/0x110 [btrfs]
May  1 08:13:20 ewzw032 kernel: [  196.718645]  [<ffffffff811ca3c0>] sync_fs_one_sb+0x20/0x30
May  1 08:13:20 ewzw032 kernel: [  196.718648]  [<ffffffff8119db59>] iterate_supers+0xe9/0xf0
May  1 08:13:20 ewzw032 kernel: [  196.718650]  [<ffffffff811ca555>] sys_sync+0x55/0x90
May  1 08:13:20 ewzw032 kernel: [  196.718654]  [<ffffffff816dfe9d>] system_call_fastpath+0x1a/0x1f
May  1 08:13:20 ewzw032 kernel: [  196.718655] ---[ end trace 88dd9bc54a43ce1a ]---