The new /sys interface like this:
#cat /sys/devices/virtual/workqueue/writeback/sched_attr
policy=0 prio=0 nice=0
# echo "policy=0 prio=0 nice=-1" >
/sys/devices/virtual/workqueue/writeback/sched_attr
# cat /sys/devices/virtual/workqueue/writeback/sched_attr
policy=0 prio=0 nice=-1
Also, the possibility of specifying more than just a priority
for the wq may be useful for a wide variety of applications.
Signed-off-by: Wen Yang <wen.yan...@zte.com.cn>
Signed-off-by: Jiang Biao <jiang.bi...@zte.com.cn>
Signed-off-by: Tan Hu <tan...@zte.com.cn>
Suggested-by: Tejun Heo <t...@kernel.org>
Cc: Tejun Heo <t...@kernel.org>
Cc: Lai Jiangshan <jiangshan...@gmail.com>
Cc: kernel test robot <xiaolong...@intel.com>
Cc: linux-kernel@vger.kernel.org
---
include/linux/workqueue.h | 5 --
kernel/workqueue.c | 130 ++++++++++++++++++++++++++++------------------
2 files changed, 79 insertions(+), 56 deletions(-)
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 9faaade..d9d0f36 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -128,11 +128,6 @@ struct delayed_work {
*/
struct workqueue_attrs {
/**
- * @nice: nice level
- */
- int nice;
-
- /**
* @sched_attr: kworker's scheduling parameters
*/
struct sched_attr sched_attr;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e1613d0..8c5aba5 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1773,7 +1773,7 @@ static struct worker *create_worker(struct worker_pool
*pool)
if (pool->cpu >= 0)
snprintf(id_buf, sizeof(id_buf), "%d:%d%s", pool->cpu, id,
- pool->attrs->nice < 0 ? "H" : "");
+ pool->attrs->sched_attr.sched_nice < 0 ? "H" : "");
else
snprintf(id_buf, sizeof(id_buf), "u%d:%d", pool->id, id);
@@ -1782,7 +1782,7 @@ static struct worker *create_worker(struct worker_pool
*pool)
if (IS_ERR(worker->task))
goto fail;
- set_user_nice(worker->task, pool->attrs->nice);
+ set_user_nice(worker->task, pool->attrs->sched_attr.sched_nice);
kthread_bind_mask(worker->task, pool->attrs->cpumask);
/* successful, attach the worker to the pool */
@@ -3179,7 +3179,6 @@ static void copy_sched_attr(struct sched_attr *to,
static void copy_workqueue_attrs(struct workqueue_attrs *to,
const struct workqueue_attrs *from)
{
- to->nice = from->nice;
copy_sched_attr(&to->sched_attr, &from->sched_attr);
cpumask_copy(to->cpumask, from->cpumask);
/*
@@ -3195,17 +3194,29 @@ static u32 wqattrs_hash(const struct workqueue_attrs
*attrs)
{
u32 hash = 0;
- hash = jhash_1word(attrs->nice, hash);
+ hash = jhash_1word(attrs->sched_attr.sched_nice, hash);
hash = jhash(cpumask_bits(attrs->cpumask),
BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long), hash);
return hash;
}
+static bool sched_attr_equal(const struct sched_attr *a,
+ const struct sched_attr *b)
+{
+ if (a->sched_policy != b->sched_policy)
+ return false;
+ if (a->sched_priority != b->sched_priority)
+ return false;
+ if (a->sched_nice != b->sched_nice)
+ return false;
+ return true;
+}
+
/* content equality test */
static bool wqattrs_equal(const struct workqueue_attrs *a,
const struct workqueue_attrs *b)
{
- if (a->nice != b->nice)
+ if (a->sched_attr.sched_nice != b->sched_attr.sched_nice)
return false;
if (!cpumask_equal(a->cpumask, b->cpumask))
return false;
@@ -3259,8 +3270,6 @@ static void rcu_free_wq(struct rcu_head *rcu)
if (!(wq->flags & WQ_UNBOUND))
free_percpu(wq->cpu_pwqs);
- else
- free_workqueue_attrs(wq->unbound_attrs);
free_workqueue_attrs(wq->attrs);
kfree(wq->rescuer);
kfree(wq);
@@ -4353,7 +4362,8 @@ static void pr_cont_pool_info(struct worker_pool *pool)
pr_cont(" cpus=%*pbl", nr_cpumask_bits, pool->attrs->cpumask);
if (pool->node != NUMA_NO_NODE)
pr_cont(" node=%d", pool->node);
- pr_cont(" flags=0x%x nice=%d", pool->flags, pool->attrs->nice);
+ pr_cont(" flags=0x%x nice=%d", pool->flags,
+ pool->attrs->sched_attr.sched_nice);
}
static void pr_cont_work(bool comma, struct work_struct *work)
@@ -5074,7 +5084,64 @@ static ssize_t sched_attr_show(struct device *dev,
return written;
}
-static DEVICE_ATTR_RO(sched_attr);
+static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct
*wq);
+
+static int wq_set_unbound_sched_attr(struct workqueue_struct *wq,
+ const struct sched_attr *new)
+{
+ struct workqueue_attrs *attrs;
+ int ret = -ENOMEM;
+
+ apply_wqattrs_lock();
+ attrs = wq_sysfs_prep_attrs(wq);
+ if (!attrs)
+ goto out_unlock;
+ copy_sched_attr(&attrs->sched_attr, new);
+ ret = apply_workqueue_attrs_locked(wq, attrs);
+
+out_unlock:
+ apply_wqattrs_unlock();
+ free_workqueue_attrs(attrs);
+ return ret;
+}
+
+static ssize_t sched_attr_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ struct sched_attr new = {
+ .size = sizeof(struct sched_attr),
+ .sched_policy = SCHED_NORMAL,
+ .sched_flags = 0,
+ .sched_priority = 0,
+ };
+ int ret = 0;
+
+ if (!capable(CAP_SYS_NICE))
+ return -EPERM;
+
+ if (sscanf(buf, "policy=0 prio=0 nice=%d",
+ &new.sched_nice) != 1)
+ return -EINVAL;
+
+ pr_debug("set wq's sched_attr: policy=%u prio=%u nice=%d\n",
+ new.sched_policy,
+ new.sched_priority,
+ new.sched_nice);
+ mutex_lock(&wq->mutex);
+ if (sched_attr_equal(&wq->attrs->sched_attr, &new)) {
+ mutex_unlock(&wq->mutex);
+ return count;
+ }
+ mutex_unlock(&wq->mutex);
+
+ if (wq->flags & WQ_UNBOUND)
+ ret = wq_set_unbound_sched_attr(wq, &new);
+ else
+ ret = -EPERM;
+ return ret ?: count;
+}
+static DEVICE_ATTR_RW(sched_attr);
static struct attribute *wq_sysfs_attrs[] = {
&dev_attr_per_cpu.attr,
@@ -5104,19 +5171,6 @@ static ssize_t wq_pool_ids_show(struct device *dev,
return written;
}
-static ssize_t wq_nice_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->attrs->nice);
- mutex_unlock(&wq->mutex);
-
- return written;
-}
-
/* prepare workqueue_attrs for sysfs store operations */
static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct *wq)
{
@@ -5132,31 +5186,6 @@ static struct workqueue_attrs
*wq_sysfs_prep_attrs(struct workqueue_struct *wq)
return attrs;
}
-static ssize_t wq_nice_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 ret = -ENOMEM;
-
- apply_wqattrs_lock();
-
- attrs = wq_sysfs_prep_attrs(wq);
- if (!attrs)
- goto out_unlock;
-
- if (sscanf(buf, "%d", &attrs->nice) == 1 &&
- attrs->nice >= MIN_NICE && attrs->nice <= MAX_NICE)
- ret = apply_workqueue_attrs_locked(wq, attrs);
- else
- ret = -EINVAL;
-
-out_unlock:
- apply_wqattrs_unlock();
- free_workqueue_attrs(attrs);
- return ret ?: count;
-}
-
static ssize_t wq_cpumask_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -5235,7 +5264,6 @@ static ssize_t wq_numa_store(struct device *dev, struct
device_attribute *attr,
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,
@@ -5610,7 +5638,7 @@ int __init workqueue_init_early(void)
BUG_ON(init_worker_pool(pool));
pool->cpu = cpu;
cpumask_copy(pool->attrs->cpumask, cpumask_of(cpu));
- pool->attrs->nice = std_nice[i++];
+ pool->attrs->sched_attr.sched_nice = std_nice[i++];
pool->node = cpu_to_node(cpu);
/* alloc pool ID */
@@ -5625,7 +5653,7 @@ int __init workqueue_init_early(void)
struct workqueue_attrs *attrs;
BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
- attrs->nice = std_nice[i];
+ attrs->sched_attr.sched_nice = std_nice[i];
unbound_std_wq_attrs[i] = attrs;
/*
@@ -5634,7 +5662,7 @@ int __init workqueue_init_early(void)
* Turn off NUMA so that dfl_pwq is used for all nodes.
*/
BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
- attrs->nice = std_nice[i];
+ attrs->sched_attr.sched_nice = std_nice[i];
attrs->no_numa = true;
ordered_wq_attrs[i] = attrs;
}
--
1.8.3.1
