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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 18:00:13 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 18:00:13 -0700 |
commit | d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe (patch) | |
tree | 592e040010a30d1dbce4e54eb597011af0df290e /kernel/workqueue.c | |
parent | a23867f1d2de572f84b459651dfe99fa9e79fadf (diff) | |
parent | f75da8a8a918d7c343a2ec95d1ed99e5689e0f23 (diff) | |
download | linux-stable-d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe.tar.gz linux-stable-d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe.tar.bz2 linux-stable-d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe.zip |
Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
"rcu_work addition and a couple trivial changes"
* 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: remove the comment about the old manager_arb mutex
workqueue: fix the comments of nr_idle
fs/aio: Use rcu_work instead of explicit rcu and work item
cgroup: Use rcu_work instead of explicit rcu and work item
RCU, workqueue: Implement rcu_work
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r-- | kernel/workqueue.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 254e636a3d6b..ca7959be8aaa 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -153,10 +153,9 @@ struct worker_pool { unsigned long watchdog_ts; /* L: watchdog timestamp */ struct list_head worklist; /* L: list of pending works */ - int nr_workers; /* L: total number of workers */ - /* nr_idle includes the ones off idle_list for rebinding */ - int nr_idle; /* L: currently idle ones */ + int nr_workers; /* L: total number of workers */ + int nr_idle; /* L: currently idle workers */ struct list_head idle_list; /* X: list of idle workers */ struct timer_list idle_timer; /* L: worker idle timeout */ @@ -166,7 +165,6 @@ struct worker_pool { DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER); /* L: hash of busy workers */ - /* see manage_workers() for details on the two manager mutexes */ struct worker *manager; /* L: purely informational */ struct mutex attach_mutex; /* attach/detach exclusion */ struct list_head workers; /* A: attached workers */ @@ -1604,6 +1602,40 @@ bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, } EXPORT_SYMBOL_GPL(mod_delayed_work_on); +static void rcu_work_rcufn(struct rcu_head *rcu) +{ + struct rcu_work *rwork = container_of(rcu, struct rcu_work, rcu); + + /* read the comment in __queue_work() */ + local_irq_disable(); + __queue_work(WORK_CPU_UNBOUND, rwork->wq, &rwork->work); + local_irq_enable(); +} + +/** + * queue_rcu_work - queue work after a RCU grace period + * @wq: workqueue to use + * @rwork: work to queue + * + * Return: %false if @rwork was already pending, %true otherwise. Note + * that a full RCU grace period is guaranteed only after a %true return. + * While @rwork is guarnateed to be executed after a %false return, the + * execution may happen before a full RCU grace period has passed. + */ +bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork) +{ + struct work_struct *work = &rwork->work; + + if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { + rwork->wq = wq; + call_rcu(&rwork->rcu, rcu_work_rcufn); + return true; + } + + return false; +} +EXPORT_SYMBOL(queue_rcu_work); + /** * worker_enter_idle - enter idle state * @worker: worker which is entering idle state @@ -3001,6 +3033,26 @@ bool flush_delayed_work(struct delayed_work *dwork) } EXPORT_SYMBOL(flush_delayed_work); +/** + * flush_rcu_work - wait for a rwork to finish executing the last queueing + * @rwork: the rcu work to flush + * + * Return: + * %true if flush_rcu_work() waited for the work to finish execution, + * %false if it was already idle. + */ +bool flush_rcu_work(struct rcu_work *rwork) +{ + if (test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&rwork->work))) { + rcu_barrier(); + flush_work(&rwork->work); + return true; + } else { + return flush_work(&rwork->work); + } +} +EXPORT_SYMBOL(flush_rcu_work); + static bool __cancel_work(struct work_struct *work, bool is_dwork) { unsigned long flags; |