hg: shenandoah/jdk: Provide non-taxable allocation slack at the beginning of the cycle

[ashipile at redhat.com]

Changeset: a1665e6feb5d
Author:    shade
Date:      2018-03-19 14:47 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/a1665e6feb5d

Provide non-taxable allocation slack at the beginning of the cycle

! src/hotspot/share/gc/shenandoah/shenandoahPacer.cpp
! src/hotspot/share/gc/shenandoah/shenandoahPacer.hpp
! src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp