Comment 184 for bug 620074

(In reply to comment #138)
> Maybe it's not only the preemption and the frequency. I think one of these
> things could be:
>
> General setup:
> - Control Group support DISABLED
> - Group CPU Scheduler DISABLED
> - Enable full-sized data structures for core ENABLED
> - Enable futex support ENABLED
> - Use full shmem filesystem ENABLED
> - Enable AIO support ENABLED
> - SLAB Allocator: SLUB
>
> Processor type and features (ENABLED):
> - Tickless System (NO_HZ)
> - High Resolution Timer Support
> - HPET Timer Support
> - Multi-core scheduler support
> - Preemptible RCU
> - 64 bit Memory and IO resources
> - Add LRU list to track non-evictable pages
>
> Good luck...
>

Many of these seem to be 32-bit settings. The funny thing is that if I boot into x86 32-bit, I don't see any of the slow downs or they are so little that effectively I don't feel them. Its only x86-64 which freezes on me during IO.