sched/isolation: Isolate workqueues when "nohz_full=" is set

As we prepare for offloading the residual 1hz scheduler ticks to workqueue, let's affine those to housekeepers so that they don't interrupt the CPUs that don't want to be disturbed.

Frederic Weisbecker committed 8 years ago

Commit 1bda3f81 parent 22ab8bc3 files · +5 −2Browse files

Unified · Split

3 files

include/linux/sched/isolation.h +1 −0
kernel/sched/isolation.c +2 −1
kernel/workqueue.c +2 −1

include/linux/sched/isolation.h+1−0

@@ -12,6 +12,7 @@ enum hk_flags { · 11 unmodified lines
12	12	HK_FLAG_SCHED = (1 << 3),
13	13	HK_FLAG_TICK = (1 << 4),
14	14	HK_FLAG_DOMAIN = (1 << 5),
	15	+ HK_FLAG_WQ = (1 << 6),
15	16	};
16	17
17	18	#ifdef CONFIG_CPU_ISOLATION

kernel/sched/isolation.c+2−1

@@ -3,6 +3,7 @@ · 2 unmodified lines
3	3	* any CPU: unbound workqueues, timers, kthreads and any offloadable work.
4	4	*
5	5	* Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker
	6	+ * Copyright (C) 2017-2018 SUSE, Frederic Weisbecker
6	7	*
7	8	*/
8	9
@@ -119,7 +120,7 @@ static int __init housekeeping_nohz_full_setup(char *str) · 110 unmodified lines
119	120	{
120	121	unsigned int flags;
121	122
122		− flags = HK_FLAG_TICK \| HK_FLAG_TIMER \| HK_FLAG_RCU \| HK_FLAG_MISC;
	123	+ flags = HK_FLAG_TICK \| HK_FLAG_WQ \| HK_FLAG_TIMER \| HK_FLAG_RCU \| HK_FLAG_MISC;
123	124
124	125	return housekeeping_setup(str, flags);
125	126	}

kernel/workqueue.c+2−1

@@ -5565,12 +5565,13 @@ static void __init wq_numa_init(void) · 5564 unmodified lines
5565	5565	int __init workqueue_init_early(void)
5566	5566	{
5567	5567	int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
	5568	+ int hk_flags = HK_FLAG_DOMAIN \| HK_FLAG_WQ;
5568	5569	int i, cpu;
5569	5570
5570	5571	WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
5571	5572
5572	5573	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
5573		− cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(HK_FLAG_DOMAIN));
	5574	+ cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));
5574	5575
5575	5576	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
5576	5577