Ubuntu and Whizzytex
I have an earlier post in which I pointed out that whizzytex was causing emacs to freeze intermittently. After a lot of searching and a bit of system tool use (specifically, iotop) I think I’ve pinpointed the problem (but not solved it yet).
It looks like the problem is not with Whizzytex at all, but related to known a known bug in Firefox and/or Tracker and/or Google Desktop. Or maybe something about the way fsync() and kjournald interact. These programs access disk a lot, which is what was causing the delays. Apparently this is compounded because Firefox 3 issues a large number of calls to fsync(), which in turn causes kjournald and pdflush to activate on a regular basis. This is what sometimes ties up the disk for a second or two.
A potential solution is to tell firefox to do asynchronous updation of history and bookmarks, and use a ramdisk for the Firefox cache. I tried this and also disabled tracker and gdl_indexer indexing, but I’m not sure it’s helping yet.
Update (Feb 25, 2009):
Fixed! I am fairly sure that google desktop was one of the factors behind the annoying slowdowns. I am not sure which (if any) of the other issues (firefox and tracker) was responsible. But if I disable all three, I don’t see the delays any more. I’ve been freeze-free for about 3 weeks now! I like google desktop, so I simply disable indexing before starting whizzytex and re-enable it after.