2.6.7-vanilla-SMP kernel: pagebuf_get: failed to lookup pages

[L A Walsh <lkml@xxxxxxxxx>]

Jul 20 09:07:34 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 20 09:07:34 ishtar last message repeated 25 times
Jul 20 09:26:38 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 20 09:27:09 ishtar last message repeated 354 times
Jul 20 09:27:52 ishtar last message repeated 274 times
Jul 20 09:45:46 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 20 09:45:46 ishtar last message repeated 2 times
Jul 20 10:00:10 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 02:30:00 ishtar su: (to backup) root on none
Jul 21 02:30:01 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 02:30:04 ishtar last message repeated 16 times
Jul 21 02:30:30 ishtar su: (to backup) root on none
Jul 21 02:31:55 ishtar su: (to backup) root on none
Jul 21 02:31:55 ishtar last message repeated 3 times
Jul 21 03:15:09 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 03:15:09 ishtar last message repeated 4 times
Jul 21 04:07:34 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 04:07:34 ishtar last message repeated 9 times
Jul 21 04:26:44 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 04:27:45 ishtar last message repeated 1516 times
Jul 21 04:27:54 ishtar last message repeated 36 times
Jul 21 04:45:51 ishtar kernel: pagebuf_get: failed to lookup pages
Jul 21 04:45:51 ishtar last message repeated 7 times

----

   Any idea what this message means?  I especially notice a high 
frequency during
high disk i/o.  File systems are all xfs if that is pertinent.  Backups 
run in early
AM backing up SCSI disks to a large IDE.  However, the messages around 
9:27 on the
20th wouldn't have been backup related but possibly processing a backlog of
email after some system maintenance -- and that would have all been on 
SCSI disks.