tree d24430fc0cdeea55d2028c8270925df283f8d274
parent 8e82af1166242bebd29289d2b16ce447273b427a
author Jason Evans <jasone@canonware.com> 1455941371 -0800
committer Jason Evans <jasone@canonware.com> 1455944181 -0800

Implement decay-based unused dirty page purging.

This is an alternative to the existing ratio-based unused dirty page
purging, and is intended to eventually become the sole purging
mechanism.

Add mallctls:
- opt.purge
- opt.decay_time
- arena.<i>.decay
- arena.<i>.decay_time
- arenas.decay_time
- stats.arenas.<i>.decay_time

This resolves #325.