7232 add tunables to combat scheduling delay of kernel threads Reviewed by: Paul Dagnelie <pcd@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: Sebastien Roy <sebastien.roy@delphix.com> Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net> Reviewed by: Bryan Cantrill <bryan@joyent.com> Approved by: Dan McDonald <danmcd@omniti.com>

3006 VERIFY[S,U,P] and ASSERT[S,U,P] frequently check if first argument is zero Reviewed by Matt Ahrens <matthew.ahrens@delphix.com> Reviewed by George Wilson <george.wilson@delphix.com> Approved by Eric Schrock <eric.schrock@delphix.com>

backout 3006: causes 3046 (panics after mounting root)

3006 VERIFY[S,U,P] and ASSERT[S,U,P] frequently check if first argument is zero Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org>

6941908 sysdc_leave() can race with sysdc_update() and trip over 0xdeadbeef

6909721 assertion failed: t->t_lpl < t->t_cpupart->cp_lgrploads + t->t_cpupart->cp_nlgrp 6910240 sysdc_batch_niceness doesn't help performance

6881015 ZFS write activity prevents other threads from running in a timely manner 6899867 mstate_thread_onproc_time() doesn't account for runnable time correctly PSARC/2009/615 System Duty Cycle Scheduling Class and ZFS IO Observability