From 420c0ddb1f205a3511b766d0dfee2cc87ed9dae0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 12 Mar 2013 11:29:59 -0700 Subject: [PATCH] workqueue: remove workqueue_struct->pool_wq.single workqueue->pool_wq union is used to point either to percpu pwqs (pool_workqueues) or single unbound pwq. As the first pwq can be accessed via workqueue->pwqs list, there's no reason for the single pointer anymore. Use list_first_entry(workqueue->pwqs) to access the unbound pwq and drop workqueue->pool_wq.single pointer and the pool_wq union. It simplifies the code and eases implementing multiple unbound pools w/ custom attributes. This patch doesn't introduce any visible behavior changes. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan --- kernel/workqueue.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 73c5f68065b5..acee7b525d51 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -188,11 +188,7 @@ struct wq_flusher { */ struct workqueue_struct { unsigned int flags; /* W: WQ_* flags */ - union { - struct pool_workqueue __percpu *pcpu; - struct pool_workqueue *single; - unsigned long v; - } pool_wq; /* I: pwq's */ + struct pool_workqueue __percpu *cpu_pwqs; /* I: per-cpu pwq's */ struct list_head pwqs; /* I: all pwqs of this wq */ struct list_head list; /* W: list of all workqueues */ @@ -471,9 +467,11 @@ static struct pool_workqueue *get_pwq(int cpu, struct workqueue_struct *wq) { if (!(wq->flags & WQ_UNBOUND)) { if (likely(cpu < nr_cpu_ids)) - return per_cpu_ptr(wq->pool_wq.pcpu, cpu); - } else if (likely(cpu == WORK_CPU_UNBOUND)) - return wq->pool_wq.single; + 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; } @@ -3085,8 +3083,8 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) int cpu; if (!(wq->flags & WQ_UNBOUND)) { - wq->pool_wq.pcpu = alloc_percpu(struct pool_workqueue); - if (!wq->pool_wq.pcpu) + wq->cpu_pwqs = alloc_percpu(struct pool_workqueue); + if (!wq->cpu_pwqs) return -ENOMEM; for_each_possible_cpu(cpu) { @@ -3102,7 +3100,6 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) if (!pwq) return -ENOMEM; - wq->pool_wq.single = pwq; pwq->pool = get_std_worker_pool(WORK_CPU_UNBOUND, highpri); list_add_tail(&pwq->pwqs_node, &wq->pwqs); } @@ -3113,9 +3110,10 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) static void free_pwqs(struct workqueue_struct *wq) { if (!(wq->flags & WQ_UNBOUND)) - free_percpu(wq->pool_wq.pcpu); - else - kmem_cache_free(pwq_cache, wq->pool_wq.single); + free_percpu(wq->cpu_pwqs); + else if (!list_empty(&wq->pwqs)) + kmem_cache_free(pwq_cache, list_first_entry(&wq->pwqs, + struct pool_workqueue, pwqs_node)); } static int wq_clamp_max_active(int max_active, unsigned int flags, -- 2.30.2