log: remember to free output buffer when done
[fio.git] / workqueue.c
CommitLineData
a9da8ab2 1/*
51575029 2 * Generic workqueue offload mechanism
a9da8ab2
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3 *
4 * Copyright (C) 2015 Jens Axboe <axboe@kernel.dk>
5 *
6 */
7#include <unistd.h>
8
9#include "fio.h"
a9da8ab2
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10#include "flist.h"
11#include "workqueue.h"
a47591e4 12#include "smalloc.h"
ae626d4e 13#include "pshared.h"
a9da8ab2 14
a9da8ab2
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15enum {
16 SW_F_IDLE = 1 << 0,
17 SW_F_RUNNING = 1 << 1,
18 SW_F_EXIT = 1 << 2,
d22042d2
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19 SW_F_ACCOUNTED = 1 << 3,
20 SW_F_ERROR = 1 << 4,
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21};
22
23static struct submit_worker *__get_submit_worker(struct workqueue *wq,
24 unsigned int start,
25 unsigned int end,
26 struct submit_worker **best)
27{
28 struct submit_worker *sw = NULL;
29
30 while (start <= end) {
31 sw = &wq->workers[start];
32 if (sw->flags & SW_F_IDLE)
33 return sw;
34 if (!(*best) || sw->seq < (*best)->seq)
35 *best = sw;
36 start++;
37 }
38
39 return NULL;
40}
41
42static struct submit_worker *get_submit_worker(struct workqueue *wq)
43{
44 unsigned int next = wq->next_free_worker;
45 struct submit_worker *sw, *best = NULL;
46
47 assert(next < wq->max_workers);
48
49 sw = __get_submit_worker(wq, next, wq->max_workers - 1, &best);
50 if (!sw && next)
51 sw = __get_submit_worker(wq, 0, next - 1, &best);
52
53 /*
54 * No truly idle found, use best match
55 */
56 if (!sw)
57 sw = best;
58
59 if (sw->index == wq->next_free_worker) {
60 if (sw->index + 1 < wq->max_workers)
61 wq->next_free_worker = sw->index + 1;
62 else
63 wq->next_free_worker = 0;
64 }
65
66 return sw;
67}
68
1391052a 69static bool all_sw_idle(struct workqueue *wq)
a9da8ab2
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70{
71 int i;
72
73 for (i = 0; i < wq->max_workers; i++) {
74 struct submit_worker *sw = &wq->workers[i];
75
76 if (!(sw->flags & SW_F_IDLE))
1391052a 77 return false;
a9da8ab2
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78 }
79
1391052a 80 return true;
a9da8ab2
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81}
82
83/*
84 * Must be serialized wrt workqueue_enqueue() by caller
85 */
86void workqueue_flush(struct workqueue *wq)
87{
88 wq->wake_idle = 1;
89
90 while (!all_sw_idle(wq)) {
91 pthread_mutex_lock(&wq->flush_lock);
92 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
93 pthread_mutex_unlock(&wq->flush_lock);
94 }
95
96 wq->wake_idle = 0;
97}
98
99/*
b07f6ad1 100 * Must be serialized by caller. Returns true for queued, false for busy.
a9da8ab2 101 */
26de50cf 102void workqueue_enqueue(struct workqueue *wq, struct workqueue_work *work)
a9da8ab2
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103{
104 struct submit_worker *sw;
105
106 sw = get_submit_worker(wq);
26de50cf
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107 assert(sw);
108
109 pthread_mutex_lock(&sw->lock);
110 flist_add_tail(&work->list, &sw->work_list);
111 sw->seq = ++wq->work_seq;
112 sw->flags &= ~SW_F_IDLE;
a9da8ab2 113
26de50cf 114 pthread_cond_signal(&sw->cond);
b93a8eb0 115 pthread_mutex_unlock(&sw->lock);
a9da8ab2
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116}
117
118static void handle_list(struct submit_worker *sw, struct flist_head *list)
119{
120 struct workqueue *wq = sw->wq;
88271841 121 struct workqueue_work *work;
a9da8ab2
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122
123 while (!flist_empty(list)) {
88271841
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124 work = flist_first_entry(list, struct workqueue_work, list);
125 flist_del_init(&work->list);
ee2b6d6e 126 wq->ops.fn(sw, work);
a9da8ab2
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127 }
128}
129
a9da8ab2
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130static void *worker_thread(void *data)
131{
132 struct submit_worker *sw = data;
133 struct workqueue *wq = sw->wq;
d22042d2 134 unsigned int ret = 0;
a9da8ab2
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135 FLIST_HEAD(local_list);
136
24660963
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137 sk_out_assign(sw->sk_out);
138
f6496ba7
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139 if (wq->ops.nice) {
140 if (nice(wq->ops.nice) < 0) {
141 log_err("workqueue: nice %s\n", strerror(errno));
142 ret = 1;
143 }
144 }
145
146 if (!ret)
147 ret = workqueue_init_worker(sw);
148
a9da8ab2
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149 pthread_mutex_lock(&sw->lock);
150 sw->flags |= SW_F_RUNNING;
151 if (ret)
152 sw->flags |= SW_F_ERROR;
153 pthread_mutex_unlock(&sw->lock);
154
155 pthread_mutex_lock(&wq->flush_lock);
156 pthread_cond_signal(&wq->flush_cond);
157 pthread_mutex_unlock(&wq->flush_lock);
158
159 if (sw->flags & SW_F_ERROR)
160 goto done;
161
162 while (1) {
163 pthread_mutex_lock(&sw->lock);
164
165 if (flist_empty(&sw->work_list)) {
166 if (sw->flags & SW_F_EXIT) {
167 pthread_mutex_unlock(&sw->lock);
168 break;
169 }
170
ee2b6d6e 171 if (workqueue_pre_sleep_check(sw)) {
a9da8ab2 172 pthread_mutex_unlock(&sw->lock);
ee2b6d6e 173 workqueue_pre_sleep(sw);
a9da8ab2
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174 pthread_mutex_lock(&sw->lock);
175 }
176
177 /*
178 * We dropped and reaquired the lock, check
179 * state again.
180 */
181 if (!flist_empty(&sw->work_list))
182 goto handle_work;
183
184 if (sw->flags & SW_F_EXIT) {
185 pthread_mutex_unlock(&sw->lock);
186 break;
187 } else if (!(sw->flags & SW_F_IDLE)) {
188 sw->flags |= SW_F_IDLE;
189 wq->next_free_worker = sw->index;
190 if (wq->wake_idle)
191 pthread_cond_signal(&wq->flush_cond);
192 }
17ecadc3
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193 if (wq->ops.update_acct_fn)
194 wq->ops.update_acct_fn(sw);
195
a9da8ab2
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196 pthread_cond_wait(&sw->cond, &sw->lock);
197 } else {
198handle_work:
199 flist_splice_init(&sw->work_list, &local_list);
200 }
201 pthread_mutex_unlock(&sw->lock);
202 handle_list(sw, &local_list);
203 }
204
17ecadc3
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205 if (wq->ops.update_acct_fn)
206 wq->ops.update_acct_fn(sw);
a9da8ab2
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207
208done:
24660963 209 sk_out_drop();
a9da8ab2
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210 return NULL;
211}
212
c35c582d 213static void free_worker(struct submit_worker *sw, unsigned int *sum_cnt)
a9da8ab2 214{
ee2b6d6e 215 struct workqueue *wq = sw->wq;
a9da8ab2 216
c35c582d 217 workqueue_exit_worker(sw, sum_cnt);
a9da8ab2
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218
219 pthread_cond_destroy(&sw->cond);
220 pthread_mutex_destroy(&sw->lock);
ee2b6d6e
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221
222 if (wq->ops.free_worker_fn)
223 wq->ops.free_worker_fn(sw);
a9da8ab2
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224}
225
226static void shutdown_worker(struct submit_worker *sw, unsigned int *sum_cnt)
227{
a9da8ab2 228 pthread_join(sw->thread, NULL);
c35c582d 229 free_worker(sw, sum_cnt);
a9da8ab2
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230}
231
232void workqueue_exit(struct workqueue *wq)
233{
234 unsigned int shutdown, sum_cnt = 0;
235 struct submit_worker *sw;
236 int i;
237
f8e266c9
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238 if (!wq->workers)
239 return;
240
a9da8ab2
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241 for (i = 0; i < wq->max_workers; i++) {
242 sw = &wq->workers[i];
243
244 pthread_mutex_lock(&sw->lock);
245 sw->flags |= SW_F_EXIT;
246 pthread_cond_signal(&sw->cond);
247 pthread_mutex_unlock(&sw->lock);
248 }
249
250 do {
251 shutdown = 0;
252 for (i = 0; i < wq->max_workers; i++) {
253 sw = &wq->workers[i];
254 if (sw->flags & SW_F_ACCOUNTED)
255 continue;
b7d0bbf1 256 pthread_mutex_lock(&sw->lock);
a9da8ab2 257 sw->flags |= SW_F_ACCOUNTED;
b7d0bbf1 258 pthread_mutex_unlock(&sw->lock);
a9da8ab2
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259 shutdown_worker(sw, &sum_cnt);
260 shutdown++;
261 }
262 } while (shutdown && shutdown != wq->max_workers);
263
a47591e4 264 sfree(wq->workers);
f8e266c9 265 wq->workers = NULL;
a9da8ab2
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266 pthread_mutex_destroy(&wq->flush_lock);
267 pthread_cond_destroy(&wq->flush_cond);
2a274336 268 pthread_mutex_destroy(&wq->stat_lock);
a9da8ab2
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269}
270
24660963
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271static int start_worker(struct workqueue *wq, unsigned int index,
272 struct sk_out *sk_out)
a9da8ab2
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273{
274 struct submit_worker *sw = &wq->workers[index];
275 int ret;
276
277 INIT_FLIST_HEAD(&sw->work_list);
34febb23
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278
279 ret = mutex_cond_init_pshared(&sw->lock, &sw->cond);
f9e5b5ee
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280 if (ret)
281 return ret;
34febb23 282
a9da8ab2
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283 sw->wq = wq;
284 sw->index = index;
24660963 285 sw->sk_out = sk_out;
a9da8ab2 286
ee2b6d6e
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287 if (wq->ops.alloc_worker_fn) {
288 ret = wq->ops.alloc_worker_fn(sw);
289 if (ret)
290 return ret;
291 }
292
a9da8ab2
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293 ret = pthread_create(&sw->thread, NULL, worker_thread, sw);
294 if (!ret) {
295 pthread_mutex_lock(&sw->lock);
296 sw->flags = SW_F_IDLE;
297 pthread_mutex_unlock(&sw->lock);
298 return 0;
299 }
300
c35c582d 301 free_worker(sw, NULL);
a9da8ab2
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302 return 1;
303}
304
305int workqueue_init(struct thread_data *td, struct workqueue *wq,
24660963
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306 struct workqueue_ops *ops, unsigned int max_workers,
307 struct sk_out *sk_out)
a9da8ab2
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308{
309 unsigned int running;
310 int i, error;
f9e5b5ee 311 int ret;
a9da8ab2 312
24660963 313 wq->max_workers = max_workers;
a9da8ab2 314 wq->td = td;
5bb79f69 315 wq->ops = *ops;
a9da8ab2
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316 wq->work_seq = 0;
317 wq->next_free_worker = 0;
f9e5b5ee 318
34febb23
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319 ret = mutex_cond_init_pshared(&wq->flush_lock, &wq->flush_cond);
320 if (ret)
f9e5b5ee 321 goto err;
34febb23
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322 ret = mutex_init_pshared(&wq->stat_lock);
323 if (ret)
f9e5b5ee 324 goto err;
a9da8ab2 325
a47591e4 326 wq->workers = smalloc(wq->max_workers * sizeof(struct submit_worker));
81b3c86f
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327 if (!wq->workers)
328 goto err;
a9da8ab2
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329
330 for (i = 0; i < wq->max_workers; i++)
24660963 331 if (start_worker(wq, i, sk_out))
a9da8ab2
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332 break;
333
334 wq->max_workers = i;
bddc8d16
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335 if (!wq->max_workers)
336 goto err;
a9da8ab2
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337
338 /*
339 * Wait for them all to be started and initialized
340 */
341 error = 0;
342 do {
343 struct submit_worker *sw;
344
345 running = 0;
346 pthread_mutex_lock(&wq->flush_lock);
347 for (i = 0; i < wq->max_workers; i++) {
348 sw = &wq->workers[i];
349 pthread_mutex_lock(&sw->lock);
350 if (sw->flags & SW_F_RUNNING)
351 running++;
352 if (sw->flags & SW_F_ERROR)
353 error++;
354 pthread_mutex_unlock(&sw->lock);
355 }
356
357 if (error || running == wq->max_workers) {
358 pthread_mutex_unlock(&wq->flush_lock);
359 break;
360 }
361
362 pthread_cond_wait(&wq->flush_cond, &wq->flush_lock);
363 pthread_mutex_unlock(&wq->flush_lock);
364 } while (1);
365
bddc8d16
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366 if (!error)
367 return 0;
a9da8ab2 368
bddc8d16
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369err:
370 log_err("Can't create rate workqueue\n");
371 td_verror(td, ESRCH, "workqueue_init");
372 workqueue_exit(wq);
373 return 1;
a9da8ab2 374}