libaio: use INT_MAX to signal that we don't want the ring buffer
[fio.git] / engines / libaio.c
... / ...
CommitLineData
1/*
2 * libaio engine
3 *
4 * IO engine using the Linux native aio interface.
5 *
6 */
7#include <stdio.h>
8#include <stdlib.h>
9#include <unistd.h>
10#include <errno.h>
11#include <assert.h>
12
13#include "../fio.h"
14
15#ifdef FIO_HAVE_LIBAIO
16
17#define ev_to_iou(ev) (struct io_u *) ((unsigned long) (ev)->obj)
18
19struct libaio_data {
20 io_context_t aio_ctx;
21 struct io_event *aio_events;
22 struct iocb **iocbs;
23 struct io_u **io_us;
24 int iocbs_nr;
25};
26
27struct libaio_options {
28 struct thread_data *td;
29 unsigned int userspace_reap;
30};
31
32static struct fio_option options[] = {
33 {
34 .name = "userspace_reap",
35 .type = FIO_OPT_STR_SET,
36 .off1 = offsetof(struct libaio_options, userspace_reap),
37 .help = "Use alternative user-space reap implementation",
38 },
39 {
40 .name = NULL,
41 },
42};
43
44static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u)
45{
46 struct fio_file *f = io_u->file;
47
48 if (io_u->ddir == DDIR_READ)
49 io_prep_pread(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
50 else if (io_u->ddir == DDIR_WRITE)
51 io_prep_pwrite(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
52 else if (ddir_sync(io_u->ddir))
53 io_prep_fsync(&io_u->iocb, f->fd);
54
55 return 0;
56}
57
58static struct io_u *fio_libaio_event(struct thread_data *td, int event)
59{
60 struct libaio_data *ld = td->io_ops->data;
61 struct io_event *ev;
62 struct io_u *io_u;
63
64 ev = ld->aio_events + event;
65 io_u = ev_to_iou(ev);
66
67 if (ev->res != io_u->xfer_buflen) {
68 if (ev->res > io_u->xfer_buflen)
69 io_u->error = -ev->res;
70 else
71 io_u->resid = io_u->xfer_buflen - ev->res;
72 } else
73 io_u->error = 0;
74
75 return io_u;
76}
77
78struct aio_ring {
79 unsigned id; /** kernel internal index number */
80 unsigned nr; /** number of io_events */
81 unsigned head;
82 unsigned tail;
83
84 unsigned magic;
85 unsigned compat_features;
86 unsigned incompat_features;
87 unsigned header_length; /** size of aio_ring */
88
89 struct io_event events[0];
90};
91
92#define AIO_RING_MAGIC 0xa10a10a1
93
94static int user_io_getevents(io_context_t aio_ctx, unsigned int max,
95 struct io_event *events)
96{
97 long i = 0;
98 unsigned head;
99 struct aio_ring *ring = (struct aio_ring*) aio_ctx;
100
101 while (i < max) {
102 head = ring->head;
103
104 if (head == ring->tail) {
105 /* There are no more completions */
106 break;
107 } else {
108 /* There is another completion to reap */
109 events[i] = ring->events[head];
110 read_barrier();
111 ring->head = (head + 1) % ring->nr;
112 i++;
113 }
114 }
115
116 return i;
117}
118
119static int fio_libaio_getevents(struct thread_data *td, unsigned int min,
120 unsigned int max, struct timespec *t)
121{
122 struct libaio_data *ld = td->io_ops->data;
123 struct libaio_options *o = td->eo;
124 unsigned actual_min = td->o.iodepth_batch_complete == 0 ? 0 : min;
125 int r, events = 0;
126
127 do {
128 if (o->userspace_reap == 1
129 && actual_min == 0
130 && ((struct aio_ring *)(ld->aio_ctx))->magic
131 == AIO_RING_MAGIC) {
132 r = user_io_getevents(ld->aio_ctx, max,
133 ld->aio_events + events);
134 } else {
135 r = io_getevents(ld->aio_ctx, actual_min,
136 max, ld->aio_events + events, t);
137 }
138 if (r >= 0)
139 events += r;
140 else if (r == -EAGAIN)
141 usleep(100);
142 } while (events < min);
143
144 return r < 0 ? r : events;
145}
146
147static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u)
148{
149 struct libaio_data *ld = td->io_ops->data;
150
151 fio_ro_check(td, io_u);
152
153 if (ld->iocbs_nr == (int) td->o.iodepth)
154 return FIO_Q_BUSY;
155
156 /*
157 * fsync is tricky, since it can fail and we need to do it
158 * serialized with other io. the reason is that linux doesn't
159 * support aio fsync yet. So return busy for the case where we
160 * have pending io, to let fio complete those first.
161 */
162 if (ddir_sync(io_u->ddir)) {
163 if (ld->iocbs_nr)
164 return FIO_Q_BUSY;
165
166 do_io_u_sync(td, io_u);
167 return FIO_Q_COMPLETED;
168 }
169
170 if (io_u->ddir == DDIR_TRIM) {
171 if (ld->iocbs_nr)
172 return FIO_Q_BUSY;
173
174 do_io_u_trim(td, io_u);
175 return FIO_Q_COMPLETED;
176 }
177
178 ld->iocbs[ld->iocbs_nr] = &io_u->iocb;
179 ld->io_us[ld->iocbs_nr] = io_u;
180 ld->iocbs_nr++;
181 return FIO_Q_QUEUED;
182}
183
184static void fio_libaio_queued(struct thread_data *td, struct io_u **io_us,
185 unsigned int nr)
186{
187 struct timeval now;
188 unsigned int i;
189
190 if (!fio_fill_issue_time(td))
191 return;
192
193 fio_gettime(&now, NULL);
194
195 for (i = 0; i < nr; i++) {
196 struct io_u *io_u = io_us[i];
197
198 memcpy(&io_u->issue_time, &now, sizeof(now));
199 io_u_queued(td, io_u);
200 }
201}
202
203static int fio_libaio_commit(struct thread_data *td)
204{
205 struct libaio_data *ld = td->io_ops->data;
206 struct iocb **iocbs;
207 struct io_u **io_us;
208 int ret;
209
210 if (!ld->iocbs_nr)
211 return 0;
212
213 io_us = ld->io_us;
214 iocbs = ld->iocbs;
215 do {
216 ret = io_submit(ld->aio_ctx, ld->iocbs_nr, iocbs);
217 if (ret > 0) {
218 fio_libaio_queued(td, io_us, ret);
219 io_u_mark_submit(td, ret);
220 ld->iocbs_nr -= ret;
221 io_us += ret;
222 iocbs += ret;
223 ret = 0;
224 } else if (!ret || ret == -EAGAIN || ret == -EINTR) {
225 if (!ret)
226 io_u_mark_submit(td, ret);
227 continue;
228 } else
229 break;
230 } while (ld->iocbs_nr);
231
232 return ret;
233}
234
235static int fio_libaio_cancel(struct thread_data *td, struct io_u *io_u)
236{
237 struct libaio_data *ld = td->io_ops->data;
238
239 return io_cancel(ld->aio_ctx, &io_u->iocb, ld->aio_events);
240}
241
242static void fio_libaio_cleanup(struct thread_data *td)
243{
244 struct libaio_data *ld = td->io_ops->data;
245
246 if (ld) {
247 io_destroy(ld->aio_ctx);
248 free(ld->aio_events);
249 free(ld->iocbs);
250 free(ld->io_us);
251 free(ld);
252 }
253}
254
255static int fio_libaio_init(struct thread_data *td)
256{
257 struct libaio_data *ld = malloc(sizeof(*ld));
258 struct libaio_options *o = td->eo;
259 int err = 0;
260
261 memset(ld, 0, sizeof(*ld));
262
263 /*
264 * First try passing in 0 for queue depth, since we don't
265 * care about the user ring. If that fails, the kernel is too old
266 * and we need the right depth.
267 */
268 if (!o->userspace_reap)
269 err = io_queue_init(INT_MAX, &ld->aio_ctx);
270 if (o->userspace_reap || err == -EINVAL)
271 err = io_queue_init(td->o.iodepth, &ld->aio_ctx);
272 if (err) {
273 td_verror(td, -err, "io_queue_init");
274 log_err("fio: check /proc/sys/fs/aio-max-nr\n");
275 free(ld);
276 return 1;
277 }
278
279 ld->aio_events = malloc(td->o.iodepth * sizeof(struct io_event));
280 memset(ld->aio_events, 0, td->o.iodepth * sizeof(struct io_event));
281 ld->iocbs = malloc(td->o.iodepth * sizeof(struct iocb *));
282 memset(ld->iocbs, 0, sizeof(struct iocb *));
283 ld->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
284 memset(ld->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
285 ld->iocbs_nr = 0;
286
287 td->io_ops->data = ld;
288 return 0;
289}
290
291static struct ioengine_ops ioengine = {
292 .name = "libaio",
293 .version = FIO_IOOPS_VERSION,
294 .init = fio_libaio_init,
295 .prep = fio_libaio_prep,
296 .queue = fio_libaio_queue,
297 .commit = fio_libaio_commit,
298 .cancel = fio_libaio_cancel,
299 .getevents = fio_libaio_getevents,
300 .event = fio_libaio_event,
301 .cleanup = fio_libaio_cleanup,
302 .open_file = generic_open_file,
303 .close_file = generic_close_file,
304 .get_file_size = generic_get_file_size,
305 .options = options,
306 .option_struct_size = sizeof(struct libaio_options),
307};
308
309#else /* FIO_HAVE_LIBAIO */
310
311/*
312 * When we have a proper configure system in place, we simply wont build
313 * and install this io engine. For now install a crippled version that
314 * just complains and fails to load.
315 */
316static int fio_libaio_init(struct thread_data fio_unused *td)
317{
318 log_err("fio: libaio not available\n");
319 return 1;
320}
321
322static struct ioengine_ops ioengine = {
323 .name = "libaio",
324 .version = FIO_IOOPS_VERSION,
325 .init = fio_libaio_init,
326};
327
328#endif
329
330static void fio_init fio_libaio_register(void)
331{
332 register_ioengine(&ioengine);
333}
334
335static void fio_exit fio_libaio_unregister(void)
336{
337 unregister_ioengine(&ioengine);
338}