Based on MySQL 5.5.30, including all the bug fixes in it, Percona Server 5.5.30-30.1 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release can be found in the 5.5.30-30.1 milestone at Launchpad.
Minor optimization cleanup by removing unnecessary current_thd calls. Bug fixed #1121794 (Alexey Kopytov).
Percona Server would do unnecessary slow log stats accounting even with the slow log disabled. Bug fixed #1123915 (Alexey Kopytov).
Optimization cleanup to avoid calls related to extended slow query log stats when this feature is disabled. Bug fixed #1123921 (Alexey Kopytov).
The static srv_pass_corrupt_table variable could share CPU cache lines with InnoDB row counters, which resulted in high false sharing effect in high-concurrent workloads. Bug fixed #1125259 (Alexey Kopytov).
Other bug fixes: bug fixed #1089265 (Laurynas Biveinis).