Significant performance drop in InnoDB truncation after Linux upgrade

[Bjørn Trondsen]

Hi

I use Arch Linux and after doing a full system upgrade where I upgraded the linux kernel from 3.0.something to 3.2.8, as well as updated all installed packages, the performance of innodb truncation dropped significantly.

Running "truncate table_name" on an empty-table now takes 50ms, it used to take less than 10. This is a big problem for me because I truncate databases a lot when running automated test suits when programming. Truncating an almost empty database with 20 tables take 1 second on InnoDB. On MyISAM it takes 5ms. InnoDB is now 200 times slower than MyISAM so something must be wrong.

A test suite of mine with 700 tests truncates the database 500 times, which means that a test suite that used to take 80sec to run now takes 500sec.

I use v5.5.21. I've tried downgrading to 5.5.14, 5.5.11 and 5.1.54 without seing any changes.

Im not the only linux user with this problem: https://groups.google.com/forum/?fromgroups#!topic/ruby-capybara/8LLxs4BGV-E
Does anybody have any idea what be the problem might be?