Kernel errors and hangs - need help interpereting

Hi,

I have a Linode running Ubuntu 3.9.3-x86-linode52. It runs LAMP and WordPress and some WP plugs.

Unrelated to any changes made on the admin side (but possibly related to a spike in spam WP registrations – that's my guess about what's different), the Linode likes to spike load and hang every day or so. Rebooting it restores it for a day.

htop says mysql looks like the culprit although mytop does not report any slow queries or common problems.

But I do get nightly reports via logwatch that there are kernel errors what appear to be OOMs related to the errors. I'm having a hard time parsing the reports for a course of action. I pasted a recent one here:

http://pastebin.com/eMFirM5H

If anybody would care to take a peek and make a suggestion, I would be grateful

Thanks.