Commit fcecfa8f authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: Remove module param disable_numa and sysfs knobs pool_ids and numa 



Unbound workqueue CPU affinity is going to receive an overhaul and the NUMA
specific knobs won't make sense anymore. Remove them. Also, the pool_ids
knob was used for debugging and not really meaningful given that there is no
visibility into the pools associated with those IDs. Remove it too. A future
patch will improve overall visibility.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 797e8345

Documentation/admin-guide/kernel-parameters.txt

+0 −9
Original line number Diff line number Diff line
@@ -6992,15 +6992,6 @@ 
			threshold repeatedly. They are likely good

			candidates for using WQ_UNBOUND workqueues instead.



	workqueue.disable_numa

			By default, all work items queued to unbound

			workqueues are affine to the NUMA nodes they're

			issued on, which results in better behavior in

			general.  If NUMA affinity needs to be disabled for

			whatever reason, this option can be used.  Note

			that this also can be controlled per-workqueue for

			workqueues visible under /sys/bus/workqueue/.



	workqueue.power_efficient

			Per-cpu workqueues are generally preferred because

			they show better performance thanks to cache

kernel/workqueue.c

+0 −73
Original line number Diff line number Diff line
@@ -340,9 +340,6 @@ static cpumask_var_t *wq_numa_possible_cpumask; 
static unsigned long wq_cpu_intensive_thresh_us = ULONG_MAX;

module_param_named(cpu_intensive_thresh_us, wq_cpu_intensive_thresh_us, ulong, 0644);



static bool wq_disable_numa;

module_param_named(disable_numa, wq_disable_numa, bool, 0444);



/* see the comment above the definition of WQ_POWER_EFFICIENT */

static bool wq_power_efficient = IS_ENABLED(CONFIG_WQ_POWER_EFFICIENT_DEFAULT);

module_param_named(power_efficient, wq_power_efficient, bool, 0444);
@@ -5794,10 +5791,8 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask) 
 *

 * Unbound workqueues have the following extra attributes.

 *

 *  pool_ids	RO int	: the associated pool IDs for each node

 *  nice	RW int	: nice value of the workers

 *  cpumask	RW mask	: bitmask of allowed CPUs for the workers

 *  numa	RW bool	: whether enable NUMA affinity

 */

struct wq_device {

	struct workqueue_struct		*wq;
@@ -5850,28 +5845,6 @@ static struct attribute *wq_sysfs_attrs[] = { 
};

ATTRIBUTE_GROUPS(wq_sysfs);



static ssize_t wq_pool_ids_show(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	struct workqueue_struct *wq = dev_to_wq(dev);

	const char *delim = "";

	int node, written = 0;



	cpus_read_lock();

	rcu_read_lock();

	for_each_node(node) {

		written += scnprintf(buf + written, PAGE_SIZE - written,

				     "%s%d:%d", delim, node,

				     unbound_pwq_by_node(wq, node)->pool->id);

		delim = " ";

	}

	written += scnprintf(buf + written, PAGE_SIZE - written, "\n");

	rcu_read_unlock();

	cpus_read_unlock();



	return written;

}



static ssize_t wq_nice_show(struct device *dev, struct device_attribute *attr,

			    char *buf)

{
@@ -5962,50 +5935,9 @@ static ssize_t wq_cpumask_store(struct device *dev, 
	return ret ?: count;

}



static ssize_t wq_numa_show(struct device *dev, struct device_attribute *attr,

			    char *buf)

{

	struct workqueue_struct *wq = dev_to_wq(dev);

	int written;



	mutex_lock(&wq->mutex);

	written = scnprintf(buf, PAGE_SIZE, "%d\n",

			    !wq->unbound_attrs->no_numa);

	mutex_unlock(&wq->mutex);



	return written;

}



static ssize_t wq_numa_store(struct device *dev, struct device_attribute *attr,

			     const char *buf, size_t count)

{

	struct workqueue_struct *wq = dev_to_wq(dev);

	struct workqueue_attrs *attrs;

	int v, ret = -ENOMEM;



	apply_wqattrs_lock();



	attrs = wq_sysfs_prep_attrs(wq);

	if (!attrs)

		goto out_unlock;



	ret = -EINVAL;

	if (sscanf(buf, "%d", &v) == 1) {

		attrs->no_numa = !v;

		ret = apply_workqueue_attrs_locked(wq, attrs);

	}



out_unlock:

	apply_wqattrs_unlock();

	free_workqueue_attrs(attrs);

	return ret ?: count;

}



static struct device_attribute wq_sysfs_unbound_attrs[] = {

	__ATTR(pool_ids, 0444, wq_pool_ids_show, NULL),

	__ATTR(nice, 0644, wq_nice_show, wq_nice_store),

	__ATTR(cpumask, 0644, wq_cpumask_show, wq_cpumask_store),

	__ATTR(numa, 0644, wq_numa_show, wq_numa_store),

	__ATTR_NULL,

};
@@ -6379,11 +6311,6 @@ static void __init wq_numa_init(void) 
	if (num_possible_nodes() <= 1)

		return;



	if (wq_disable_numa) {

		pr_info("workqueue: NUMA affinity support disabled\n");

		return;

	}



	for_each_possible_cpu(cpu) {

		if (WARN_ON(cpu_to_node(cpu) == NUMA_NO_NODE)) {

			pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu);