From b05a79280b346eb24ddb73b39988398015291075 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 27 Apr 2015 17:58:39 +0800 Subject: [PATCH] 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 Cc: Kevin Hilman Cc: Lai Jiangshan Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Tejun Heo Cc: Viresh Kumar Signed-off-by: Frederic Weisbecker Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo --- kernel/workqueue.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 26ff24924016..9be75e2a4da6 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -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); -- 2.30.2