One of the results from the recent crisis was that the kernel version on totoro, 3.2, is less than optimal for Postgres. It was agreed that at a suitable time (scheduled downtime), the kernel should be upgraded to at least 3.13.

References:

• Why you need to avoid Linux kernel 3.2 (Josh Berkus)
• Benchmarking PostgreSQK with different Linux kernel versions on Ubuntu LTS (Sergey Konoplev)
• Thread summary: the Linux kernel and PostgreSQL (Mel Gorman)
• PostgreSQL pain points (Jonathan Corbet, LWN)

Konoplev's benchmark results suggest that kernel.sched_autogroup_enabled should be set for 3.13 (unlike for earlier versions, where it is known to make things worse instead).