From 042f7df15a4fff8eec42873f755aea848dcdedd1 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Thu, 30 Apr 2015 17:16:12 +0800 Subject: workqueue: Allow modifying low level unbound workqueue cpumask Allow to modify the low-level unbound workqueues cpumask through sysfs. This is performed by traversing the entire workqueue list and calling apply_wqattrs_prepare() on the unbound workqueues with the new low level mask. Only after all the preparation are done, we commit them all together. Ordered workqueues are ignored from the low level unbound workqueue cpumask, it will be handled in near future. All the (default & per-node) pwqs are mandatorily controlled by the low level cpumask. If the user configured cpumask doesn't overlap with the low level cpumask, the low level cpumask will be used for the wq instead. The comment of wq_calc_node_cpumask() is updated and explicitly requires that its first argument should be the attrs of the default pwq. The default wq_unbound_cpumask is cpu_possible_mask. The workqueue subsystem doesn't know its best default value, let the system manager or the other subsystem set it when needed. Changed from V8: merge the calculating code for the attrs of the default pwq together. minor change the code&comments for saving the user configured attrs. remove unnecessary list_del(). minor update the comment of wq_calc_node_cpumask(). update the comment of workqueue_set_unbound_cpumask(); Cc: Christoph Lameter Cc: Kevin Hilman Cc: Lai Jiangshan Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Tejun Heo Cc: Viresh Kumar Cc: Frederic Weisbecker Original-patch-by: Frederic Weisbecker Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo --- include/linux/workqueue.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index deee212af8e0..4618dd672d1b 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -424,6 +424,7 @@ struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask); void free_workqueue_attrs(struct workqueue_attrs *attrs); int apply_workqueue_attrs(struct workqueue_struct *wq, const struct workqueue_attrs *attrs); +int workqueue_set_unbound_cpumask(cpumask_var_t cpumask); extern bool queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work); -- cgit v1.2.3-58-ga151 From 37b1ef31a568fc02e53587620226e5f3c66454c8 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Wed, 20 May 2015 14:41:19 +0800 Subject: workqueue: move flush_scheduled_work() to workqueue.h flush_scheduled_work() is just a simple call to flush_work(). Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo --- include/linux/workqueue.h | 30 +++++++++++++++++++++++++++++- kernel/workqueue.c | 30 ------------------------------ 2 files changed, 29 insertions(+), 31 deletions(-) (limited to 'include') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 4618dd672d1b..738b30b39b68 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -435,7 +435,6 @@ extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, extern void flush_workqueue(struct workqueue_struct *wq); extern void drain_workqueue(struct workqueue_struct *wq); -extern void flush_scheduled_work(void); extern int schedule_on_each_cpu(work_func_t func); @@ -531,6 +530,35 @@ static inline bool schedule_work(struct work_struct *work) return queue_work(system_wq, work); } +/** + * flush_scheduled_work - ensure that any scheduled work has run to completion. + * + * Forces execution of the kernel-global workqueue and blocks until its + * completion. + * + * Think twice before calling this function! It's very easy to get into + * trouble if you don't take great care. Either of the following situations + * will lead to deadlock: + * + * One of the work items currently on the workqueue needs to acquire + * a lock held by your code or its caller. + * + * Your code is running in the context of a work routine. + * + * They will be detected by lockdep when they occur, but the first might not + * occur very often. It depends on what work items are on the workqueue and + * what locks they need, which you have no control over. + * + * In most situations flushing the entire workqueue is overkill; you merely + * need to know that a particular work item isn't queued and isn't running. + * In such cases you should use cancel_delayed_work_sync() or + * cancel_work_sync() instead. + */ +static inline void flush_scheduled_work(void) +{ + flush_workqueue(system_wq); +} + /** * schedule_delayed_work_on - queue work in global workqueue on CPU after delay * @cpu: cpu to use diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ad8dc2b9efc3..c9eaa4e5c867 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2958,36 +2958,6 @@ int schedule_on_each_cpu(work_func_t func) return 0; } -/** - * flush_scheduled_work - ensure that any scheduled work has run to completion. - * - * Forces execution of the kernel-global workqueue and blocks until its - * completion. - * - * Think twice before calling this function! It's very easy to get into - * trouble if you don't take great care. Either of the following situations - * will lead to deadlock: - * - * One of the work items currently on the workqueue needs to acquire - * a lock held by your code or its caller. - * - * Your code is running in the context of a work routine. - * - * They will be detected by lockdep when they occur, but the first might not - * occur very often. It depends on what work items are on the workqueue and - * what locks they need, which you have no control over. - * - * In most situations flushing the entire workqueue is overkill; you merely - * need to know that a particular work item isn't queued and isn't running. - * In such cases you should use cancel_delayed_work_sync() or - * cancel_work_sync() instead. - */ -void flush_scheduled_work(void) -{ - flush_workqueue(system_wq); -} -EXPORT_SYMBOL(flush_scheduled_work); - /** * execute_in_process_context - reliably execute the routine with user context * @fn: the function to execute -- cgit v1.2.3-58-ga151