InnoDB semaphores resulted in extra CPU load

MySQL & MariaDB Other MySQL® Questions
1

Hi!
As you can see on picture below, at about 5:00, Sunday, July 1, CPU load raised up to 7% with no known reason. It’s slave server, and master faced same problem at same time.
The only visible correlation are InnoDB Semaphores.
But what is the reason?

CentOS Linux release 6.0
2.6.32-71.29.1.el6.x86_64
Percona-Server-server-55-5.5.16-rel22.0.189.rhel6.x86_64

Sorry for long picture.

1168×6623 549 KB

2

Denis, this could be your problem http://blog.mozilla.org/it/2012/06/30/mysql-and-the-leap-sec ond-high-cpu-and-the-fix/

3

Yes, that’s it!
Thank you!