I can see the __alloc_pages_slowpath error on a Thinkpad R61e running kernel 2.6.32-24-generic #38-Ubuntu SMP.
I haven't tested any mainline build yet.

The stack trace is as below.

[   26.207921] WARNING: at /build/buildd/linux-2.6.32/mm/page_alloc.c:1806 __alloc_pages_slowpath+0x433/0x4a0()
[   26.207924] Hardware name: 7650DNG
[   26.207925] Modules linked in: dm_crypt ipt_REJECT ipt_LOG xt_limit xt_tcpudp snd_hda_codec_conexant ipt_addrtype xt_state snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm ip6table_filter ip6_tables snd_seq_dummy arc4 nf_nat_irc snd_seq_oss pcmcia nf_conntrack_irc snd_seq_midi nf_nat_ftp nf_nat snd_rawmidi nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack_ftp snd_seq_midi_event nf_conntrack snd_seq iptable_filter snd_timer snd_seq_device iwlagn iwlcore ip_tables x_tables thinkpad_acpi led_class mac80211 yenta_socket rsrc_nonstatic psmouse nvram snd serio_raw pcmcia_core cfg80211 soundcore snd_page_alloc lp parport dm_raid45 xor fbcon tileblit font bitblit softcursor vga16fb vgastate i915 drm_kms_helper drm tg3 ahci intel_agp agpgart i2c_algo_bit video output ramzswap xvmalloc lzo_decompress lzo_compress
[   26.207992] Pid: 1017, comm: mount Not tainted 2.6.32-24-generic #38-Ubuntu
[   26.207994] Call Trace:
[   26.208000]  [<c014c492>] warn_slowpath_common+0x72/0xa0
[   26.208003]  [<c01d01d3>] ? __alloc_pages_slowpath+0x433/0x4a0
[   26.208007]  [<c01d01d3>] ? __alloc_pages_slowpath+0x433/0x4a0
[   26.208010]  [<c014c4da>] warn_slowpath_null+0x1a/0x20
[   26.208013]  [<c01d01d3>] __alloc_pages_slowpath+0x433/0x4a0
[   26.208016]  [<c01cfa7f>] ? get_page_from_freelist+0x27f/0x360
[   26.208020]  [<c021a52c>] ? __d_instantiate+0x9c/0xd0
[   26.208024]  [<c01d037a>] __alloc_pages_nodemask+0x13a/0x170
[   26.208027]  [<c01d03cc>] __get_free_pages+0x1c/0x30
[   26.208030]  [<c01fe109>] __kmalloc+0xf9/0x190
[   26.208034]  [<c022098f>] ? mntput_no_expire+0x1f/0xe0
[   26.208038]  [<c0354d3e>] match_number+0x2e/0xa0
[   26.208041]  [<c0354dda>] match_int+0xa/0x10
[   26.208047]  [<c02a22bc>] parse_options+0x17c/0x800
[   26.208048]  [<c034b7af>] ? _atomic_dec_and_lock+0x1f/0x80
[   26.208053]  [<c058bb39>] ? mutex_lock+0x19/0x40
[   26.208056]  [<c02a390a>] ext4_remount+0xca/0x450
[   26.208059]  [<c021977f>] ? prune_one_dentry+0x4f/0xc0
[   26.208063]  [<c02a3840>] ? ext4_remount+0x0/0x450
[   26.208066]  [<c020a223>] do_remount_sb+0x73/0x160
[   26.208069]  [<c0220607>] do_remount+0x137/0x1b0
[   26.208072]  [<c02228e4>] do_mount+0x174/0x200
[   26.208075]  [<c02229db>] sys_mount+0x6b/0xa0
[   26.208078]  [<c01033ec>] syscall_call+0x7/0xb

I have seen a different but probably related error on the previous kernel (2.6.32-23-generic #37-Ubuntu) : 

[ 1451.368823] WARNING: at /build/buildd/linux-2.6.32/fs/buffer.c:1159 mark_buffer_dirty+0x70/0x90()
[ 1451.368829] Hardware name: 7650DNG
[ 1451.368832] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat usb_storage aes_i586 aes_generic binfmt_misc vboxnetadp vboxnetflt vboxdrv dm_crypt ipt_REJECT ipt_LOG xt_limit xt_tcpudp ipt_addrtype xt_state snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm arc4 ip6table_filter ip6_tables nf_nat_irc thinkpad_acpi nf_conntrack_irc snd_seq_dummy nf_nat_ftp nf_nat snd_seq_oss nf_conntrack_ipv4 nf_defrag_ipv4 snd_seq_midi nf_conntrack_ftp snd_rawmidi nf_conntrack pcmcia iptable_filter snd_seq_midi_event snd_seq ip_tables iwlagn x_tables snd_timer snd_seq_device iwlcore yenta_socket rsrc_nonstatic mac80211 snd pcmcia_core led_class nvram psmouse serio_raw cfg80211 soundcore snd_page_alloc lp parport dm_raid45 xor fbcon tileblit font bitblit softcursor vga16fb vgastate i915 drm_kms_helper drm intel_agp i2c_algo_bit tg3 ahci video output agpgart ramzswap xvmalloc lzo_decompress lzo_compress
[ 1451.368967] Pid: 2626, comm: Thunar Tainted: G        W  2.6.32-23-generic #37-Ubuntu
[ 1451.368973] Call Trace:
[ 1451.368985]  [<c014c492>] warn_slowpath_common+0x72/0xa0
[ 1451.368992]  [<c022ce00>] ? mark_buffer_dirty+0x70/0x90
[ 1451.368999]  [<c022ce00>] ? mark_buffer_dirty+0x70/0x90
[ 1451.369007]  [<c014c4da>] warn_slowpath_null+0x1a/0x20
[ 1451.369014]  [<c022ce00>] mark_buffer_dirty+0x70/0x90
[ 1451.369022]  [<c027048a>] T.1002+0x4a/0x70
[ 1451.369029]  [<c027051b>] ext3_handle_error+0x6b/0xb0
[ 1451.369037]  [<c0589bc6>] ? printk+0x1d/0x1f
[ 1451.369044]  [<c02708c6>] ext3_error+0x56/0x60
[ 1451.369052]  [<c026d62c>] ext3_find_entry+0x22c/0x3c0
[ 1451.369061]  [<c0130440>] ? kunmap_atomic+0x60/0x70
[ 1451.369069]  [<c021a52c>] ? __d_instantiate+0x9c/0xd0
[ 1451.369077]  [<c026d805>] ext3_lookup+0x45/0x100
[ 1451.369085]  [<c058c32d>] ? _spin_lock+0xd/0x10
[ 1451.369092]  [<c021b84b>] ? d_alloc+0x13b/0x190
[ 1451.369100]  [<c0211177>] real_lookup+0xb7/0x110
[ 1451.369108]  [<c0212bc5>] do_lookup+0x95/0xc0
[ 1451.369115]  [<c016edea>] ? in_group_p+0x2a/0x30
[ 1451.369123]  [<c02134b3>] __link_path_walk+0x603/0xca0
[ 1451.369131]  [<c01e3348>] ? do_anonymous_page+0xa8/0x270
[ 1451.369140]  [<c0213d64>] path_walk+0x54/0xc0
[ 1451.369187]  [<c0213ee9>] do_path_lookup+0x59/0x90
[ 1451.369195]  [<c0214a31>] user_path_at+0x41/0x80
[ 1451.369203]  [<c01edc2c>] ? anon_vma_unlink+0x6c/0x70
[ 1451.369211]  [<c020c89a>] vfs_fstatat+0x3a/0x70
[ 1451.369218]  [<c020c930>] vfs_lstat+0x20/0x30
[ 1451.369225]  [<c020c959>] sys_lstat64+0x19/0x30

Please let me know if any more information is needed.
Thanks and regards,
- Amit