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: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 26ff249..9be75e2 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -299,6 +299,8 @@
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 @@
/* 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 @@
.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 @@
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);