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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-04 04:00:13 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-04 04:00:13 +0300 |
commit | d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe (patch) | |
tree | 592e040010a30d1dbce4e54eb597011af0df290e /kernel | |
parent | a23867f1d2de572f84b459651dfe99fa9e79fadf (diff) | |
parent | f75da8a8a918d7c343a2ec95d1ed99e5689e0f23 (diff) | |
download | linux-d92cd810e64aa7cf22b05f0ea1c7d3e8dbae75fe.tar.xz |
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')
-rw-r--r-- | kernel/cgroup/cgroup.c | 21 | ||||
-rw-r--r-- | kernel/workqueue.c | 60 |
2 files changed, 63 insertions, 18 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 4bfb2908ec15..a662bfcbea0e 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4524,10 +4524,10 @@ static struct cftype cgroup_base_files[] = { * and thus involve punting to css->destroy_work adding two additional * steps to the already complex sequence. */ -static void css_free_work_fn(struct work_struct *work) +static void css_free_rwork_fn(struct work_struct *work) { - struct cgroup_subsys_state *css = - container_of(work, struct cgroup_subsys_state, destroy_work); + struct cgroup_subsys_state *css = container_of(to_rcu_work(work), + struct cgroup_subsys_state, destroy_rwork); struct cgroup_subsys *ss = css->ss; struct cgroup *cgrp = css->cgroup; @@ -4573,15 +4573,6 @@ static void css_free_work_fn(struct work_struct *work) } } -static void css_free_rcu_fn(struct rcu_head *rcu_head) -{ - struct cgroup_subsys_state *css = - container_of(rcu_head, struct cgroup_subsys_state, rcu_head); - - INIT_WORK(&css->destroy_work, css_free_work_fn); - queue_work(cgroup_destroy_wq, &css->destroy_work); -} - static void css_release_work_fn(struct work_struct *work) { struct cgroup_subsys_state *css = @@ -4631,7 +4622,8 @@ static void css_release_work_fn(struct work_struct *work) mutex_unlock(&cgroup_mutex); - call_rcu(&css->rcu_head, css_free_rcu_fn); + INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn); + queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork); } static void css_release(struct percpu_ref *ref) @@ -4765,7 +4757,8 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, err_list_del: list_del_rcu(&css->sibling); err_free_css: - call_rcu(&css->rcu_head, css_free_rcu_fn); + INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn); + queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork); return ERR_PTR(err); } 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; |