Commit b05a7928 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Tejun Heo
Browse files

workqueue: Create low-level unbound workqueues cpumask 



Create a cpumask that limits the affinity of all unbound workqueues.
This cpumask is controlled through a file at the root of the workqueue
sysfs directory.

It works on a lower-level than the per WQ_SYSFS workqueues cpumask files
such that the effective cpumask applied for a given unbound workqueue is
the intersection of /sys/devices/virtual/workqueue/$WORKQUEUE/cpumask and
the new /sys/devices/virtual/workqueue/cpumask file.

This patch implements the basic infrastructure and the read interface.
wq_unbound_cpumask is initially set to cpu_possible_mask.

Cc: Christoph Lameter <cl@linux.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 2d5f0764

kernel/workqueue.c

+27 −2
Original line number Diff line number Diff line
@@ -299,6 +299,8 @@ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ 
static LIST_HEAD(workqueues);		/* PR: list of all workqueues */

static bool workqueue_freezing;		/* PL: have wqs started freezing? */



static cpumask_var_t wq_unbound_cpumask;



/* the per-cpu worker pools */

static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],

				     cpu_worker_pools);
@@ -3532,7 +3534,7 @@ apply_wqattrs_prepare(struct workqueue_struct *wq, 


	/* make a copy of @attrs and sanitize it */

	copy_workqueue_attrs(new_attrs, attrs);

	cpumask_and(new_attrs->cpumask, new_attrs->cpumask, cpu_possible_mask);

	cpumask_and(new_attrs->cpumask, new_attrs->cpumask, wq_unbound_cpumask);



	/*

	 * We may create multiple pwqs with differing cpumasks.  Make a
@@ -4945,9 +4947,29 @@ static struct bus_type wq_subsys = { 
	.dev_groups			= wq_sysfs_groups,

};



static ssize_t wq_unbound_cpumask_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	int written;



	written = scnprintf(buf, PAGE_SIZE, "%*pb\n",

			    cpumask_pr_args(wq_unbound_cpumask));



	return written;

}



static struct device_attribute wq_sysfs_cpumask_attr =

	__ATTR(cpumask, 0444, wq_unbound_cpumask_show, NULL);



static int __init wq_sysfs_init(void)

{

	return subsys_virtual_register(&wq_subsys, NULL);

	int err;



	err = subsys_virtual_register(&wq_subsys, NULL);

	if (err)

		return err;



	return device_create_file(wq_subsys.dev_root, &wq_sysfs_cpumask_attr);

}

core_initcall(wq_sysfs_init);
@@ -5095,6 +5117,9 @@ static int __init init_workqueues(void) 


	WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));



	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));

	cpumask_copy(wq_unbound_cpumask, cpu_possible_mask);



	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);



	cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);

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