From 7fb98ea79cecb14fc1735544146be06fdb1944c3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 12 Mar 2013 11:30:00 -0700 Subject: [PATCH] workqueue: replace get_pwq() with explicit per_cpu_ptr() accesses and first_pwq() get_pwq() takes @cpu, which can also be WORK_CPU_UNBOUND, and @wq and returns the matching pwq (pool_workqueue). We want to move away from using @cpu for identifying pools and pwqs for unbound pools with custom attributes and there is only one user - workqueue_congested() - which makes use of the WQ_UNBOUND conditional in get_pwq(). All other users already know whether they're dealing with a per-cpu or unbound workqueue. Replace get_pwq() with explicit per_cpu_ptr(wq->cpu_pwqs, cpu) for per-cpu workqueues and first_pwq() for unbound ones, and open-code WQ_UNBOUND conditional in workqueue_congested(). Note that this makes workqueue_congested() behave sligntly differently when @cpu other than WORK_CPU_UNBOUND is specified. It ignores @cpu for unbound workqueues and always uses the first pwq instead of oopsing. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan --- kernel/workqueue.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index acee7b5..577ac71 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -463,16 +463,9 @@ static struct worker_pool *get_std_worker_pool(int cpu, bool highpri) return &pools[highpri]; } -static struct pool_workqueue *get_pwq(int cpu, struct workqueue_struct *wq) +static struct pool_workqueue *first_pwq(struct workqueue_struct *wq) { - if (!(wq->flags & WQ_UNBOUND)) { - if (likely(cpu < nr_cpu_ids)) - return per_cpu_ptr(wq->cpu_pwqs, cpu); - } else if (likely(cpu == WORK_CPU_UNBOUND)) { - return list_first_entry(&wq->pwqs, struct pool_workqueue, - pwqs_node); - } - return NULL; + return list_first_entry(&wq->pwqs, struct pool_workqueue, pwqs_node); } static unsigned int work_color_to_flags(int color) @@ -1191,7 +1184,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, * work needs to be queued on that cpu to guarantee * non-reentrancy. */ - pwq = get_pwq(cpu, wq); + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); last_pool = get_work_pool(work); if (last_pool && last_pool != pwq->pool) { @@ -1202,7 +1195,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, worker = find_worker_executing_work(last_pool, work); if (worker && worker->current_pwq->wq == wq) { - pwq = get_pwq(last_pool->cpu, wq); + pwq = per_cpu_ptr(wq->cpu_pwqs, last_pool->cpu); } else { /* meh... not running there, queue here */ spin_unlock(&last_pool->lock); @@ -1212,7 +1205,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, spin_lock(&pwq->pool->lock); } } else { - pwq = get_pwq(WORK_CPU_UNBOUND, wq); + pwq = first_pwq(wq); spin_lock(&pwq->pool->lock); } @@ -1650,7 +1643,7 @@ static void rebind_workers(struct worker_pool *pool) else wq = system_wq; - insert_work(get_pwq(pool->cpu, wq), rebind_work, + insert_work(per_cpu_ptr(wq->cpu_pwqs, pool->cpu), rebind_work, worker->scheduled.next, work_color_to_flags(WORK_NO_COLOR)); } @@ -3088,7 +3081,8 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) return -ENOMEM; for_each_possible_cpu(cpu) { - struct pool_workqueue *pwq = get_pwq(cpu, wq); + struct pool_workqueue *pwq = + per_cpu_ptr(wq->cpu_pwqs, cpu); pwq->pool = get_std_worker_pool(cpu, highpri); list_add_tail(&pwq->pwqs_node, &wq->pwqs); @@ -3343,7 +3337,12 @@ EXPORT_SYMBOL_GPL(workqueue_set_max_active); */ bool workqueue_congested(int cpu, struct workqueue_struct *wq) { - struct pool_workqueue *pwq = get_pwq(cpu, wq); + struct pool_workqueue *pwq; + + if (!(wq->flags & WQ_UNBOUND)) + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); + else + pwq = first_pwq(wq); return !list_empty(&pwq->delayed_works); } -- 2.7.4