2 * Generic workqueue offload mechanism
4 * Copyright (C) 2015 Jens Axboe <axboe@kernel.dk>
11 #include "workqueue.h"
17 SW_F_RUNNING = 1 << 1,
19 SW_F_ACCOUNTED = 1 << 3,
23 static struct submit_worker *__get_submit_worker(struct workqueue *wq,
26 struct submit_worker **best)
28 struct submit_worker *sw = NULL;
30 while (start <= end) {
31 sw = &wq->workers[start];
32 if (sw->flags & SW_F_IDLE)
34 if (!(*best) || sw->seq < (*best)->seq)
42 static struct submit_worker *get_submit_worker(struct workqueue *wq)
44 unsigned int next = wq->next_free_worker;
45 struct submit_worker *sw, *best = NULL;
47 assert(next < wq->max_workers);
49 sw = __get_submit_worker(wq, next, wq->max_workers - 1, &best);
51 sw = __get_submit_worker(wq, 0, next - 1, &best);
54 * No truly idle found, use best match
59 if (sw->index == wq->next_free_worker) {
60 if (sw->index + 1 < wq->max_workers)
61 wq->next_free_worker = sw->index + 1;
63 wq->next_free_worker = 0;
69 static bool all_sw_idle(struct workqueue *wq)
73 for (i = 0; i < wq->max_workers; i++) {
74 struct submit_worker *sw = &wq->workers[i];
76 if (!(sw->flags & SW_F_IDLE))
84 * Must be serialized wrt workqueue_enqueue() by caller
86 void workqueue_flush(struct workqueue *wq)
88 pthread_mutex_lock(&wq->flush_lock);
91 while (!all_sw_idle(wq))
92 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
95 pthread_mutex_unlock(&wq->flush_lock);
99 * Must be serialized by caller.
101 void workqueue_enqueue(struct workqueue *wq, struct workqueue_work *work)
103 struct submit_worker *sw;
105 sw = get_submit_worker(wq);
108 pthread_mutex_lock(&sw->lock);
109 flist_add_tail(&work->list, &sw->work_list);
110 sw->seq = ++wq->work_seq;
111 sw->flags &= ~SW_F_IDLE;
113 pthread_cond_signal(&sw->cond);
114 pthread_mutex_unlock(&sw->lock);
117 static void handle_list(struct submit_worker *sw, struct flist_head *list)
119 struct workqueue *wq = sw->wq;
120 struct workqueue_work *work;
122 while (!flist_empty(list)) {
123 work = flist_first_entry(list, struct workqueue_work, list);
124 flist_del_init(&work->list);
125 wq->ops.fn(sw, work);
129 static void *worker_thread(void *data)
131 struct submit_worker *sw = data;
132 struct workqueue *wq = sw->wq;
133 unsigned int ret = 0;
134 FLIST_HEAD(local_list);
136 sk_out_assign(sw->sk_out);
139 if (nice(wq->ops.nice) < 0) {
140 log_err("workqueue: nice %s\n", strerror(errno));
146 ret = workqueue_init_worker(sw);
148 pthread_mutex_lock(&sw->lock);
149 sw->flags |= SW_F_RUNNING;
151 sw->flags |= SW_F_ERROR;
152 pthread_mutex_unlock(&sw->lock);
154 pthread_mutex_lock(&wq->flush_lock);
155 pthread_cond_signal(&wq->flush_cond);
156 pthread_mutex_unlock(&wq->flush_lock);
158 if (sw->flags & SW_F_ERROR)
161 pthread_mutex_lock(&sw->lock);
163 if (flist_empty(&sw->work_list)) {
164 if (sw->flags & SW_F_EXIT) {
168 if (workqueue_pre_sleep_check(sw)) {
169 pthread_mutex_unlock(&sw->lock);
170 workqueue_pre_sleep(sw);
171 pthread_mutex_lock(&sw->lock);
175 * We dropped and reaquired the lock, check
178 if (!flist_empty(&sw->work_list))
181 if (sw->flags & SW_F_EXIT) {
183 } else if (!(sw->flags & SW_F_IDLE)) {
184 sw->flags |= SW_F_IDLE;
185 wq->next_free_worker = sw->index;
187 pthread_cond_signal(&wq->flush_cond);
190 pthread_cond_wait(&sw->cond, &sw->lock);
193 flist_splice_init(&sw->work_list, &local_list);
195 pthread_mutex_unlock(&sw->lock);
196 handle_list(sw, &local_list);
197 if (wq->ops.update_acct_fn)
198 wq->ops.update_acct_fn(sw);
199 pthread_mutex_lock(&sw->lock);
201 pthread_mutex_unlock(&sw->lock);
208 static void free_worker(struct submit_worker *sw, unsigned int *sum_cnt)
210 struct workqueue *wq = sw->wq;
212 workqueue_exit_worker(sw, sum_cnt);
214 pthread_cond_destroy(&sw->cond);
215 pthread_mutex_destroy(&sw->lock);
217 if (wq->ops.free_worker_fn)
218 wq->ops.free_worker_fn(sw);
221 static void shutdown_worker(struct submit_worker *sw, unsigned int *sum_cnt)
223 pthread_join(sw->thread, NULL);
224 free_worker(sw, sum_cnt);
227 void workqueue_exit(struct workqueue *wq)
229 unsigned int shutdown, sum_cnt = 0;
230 struct submit_worker *sw;
236 for (i = 0; i < wq->max_workers; i++) {
237 sw = &wq->workers[i];
239 pthread_mutex_lock(&sw->lock);
240 sw->flags |= SW_F_EXIT;
241 pthread_cond_signal(&sw->cond);
242 pthread_mutex_unlock(&sw->lock);
247 for (i = 0; i < wq->max_workers; i++) {
248 sw = &wq->workers[i];
249 if (sw->flags & SW_F_ACCOUNTED)
251 pthread_mutex_lock(&sw->lock);
252 sw->flags |= SW_F_ACCOUNTED;
253 pthread_mutex_unlock(&sw->lock);
254 shutdown_worker(sw, &sum_cnt);
257 } while (shutdown && shutdown != wq->max_workers);
261 pthread_mutex_destroy(&wq->flush_lock);
262 pthread_cond_destroy(&wq->flush_cond);
263 pthread_mutex_destroy(&wq->stat_lock);
266 static int start_worker(struct workqueue *wq, unsigned int index,
267 struct sk_out *sk_out)
269 struct submit_worker *sw = &wq->workers[index];
272 INIT_FLIST_HEAD(&sw->work_list);
274 ret = mutex_cond_init_pshared(&sw->lock, &sw->cond);
282 if (wq->ops.alloc_worker_fn) {
283 ret = wq->ops.alloc_worker_fn(sw);
288 ret = pthread_create(&sw->thread, NULL, worker_thread, sw);
290 pthread_mutex_lock(&sw->lock);
291 sw->flags = SW_F_IDLE;
292 pthread_mutex_unlock(&sw->lock);
296 free_worker(sw, NULL);
300 int workqueue_init(struct thread_data *td, struct workqueue *wq,
301 struct workqueue_ops *ops, unsigned int max_workers,
302 struct sk_out *sk_out)
304 unsigned int running;
308 wq->max_workers = max_workers;
312 wq->next_free_worker = 0;
314 ret = mutex_cond_init_pshared(&wq->flush_lock, &wq->flush_cond);
317 ret = mutex_init_pshared(&wq->stat_lock);
321 wq->workers = smalloc(wq->max_workers * sizeof(struct submit_worker));
325 for (i = 0; i < wq->max_workers; i++)
326 if (start_worker(wq, i, sk_out))
330 if (!wq->max_workers)
334 * Wait for them all to be started and initialized
337 pthread_mutex_lock(&wq->flush_lock);
339 struct submit_worker *sw;
342 for (i = 0; i < wq->max_workers; i++) {
343 sw = &wq->workers[i];
344 pthread_mutex_lock(&sw->lock);
345 if (sw->flags & SW_F_RUNNING)
347 if (sw->flags & SW_F_ERROR)
349 pthread_mutex_unlock(&sw->lock);
352 if (error || running == wq->max_workers)
355 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
357 pthread_mutex_unlock(&wq->flush_lock);
363 log_err("Can't create rate workqueue\n");
364 td_verror(td, ESRCH, "workqueue_init");