2 * read/write() engine that uses syslet to be async
14 #ifdef FIO_HAVE_SYSLET
18 unsigned int nr_events;
20 struct async_head_user ahu;
21 struct syslet_uatom **ring;
25 * Inspect the ring to see if we have completed events
27 static void fio_syslet_complete(struct thread_data *td)
29 struct syslet_data *sd = td->io_ops->data;
32 struct syslet_uatom *atom;
36 atom = sd->ring[sd->ahu.user_ring_idx];
40 sd->ring[sd->ahu.user_ring_idx] = NULL;
41 if (++sd->ahu.user_ring_idx == td->iodepth)
42 sd->ahu.user_ring_idx = 0;
47 io_u->resid = io_u->xfer_buflen - ret;
51 sd->events[sd->nr_events++] = io_u;
55 static int fio_syslet_getevents(struct thread_data *td, int min,
57 struct timespec fio_unused *t)
59 struct syslet_data *sd = td->io_ops->data;
64 fio_syslet_complete(td);
67 * do we have enough immediate completions?
69 if (sd->nr_events >= (unsigned int) min)
73 * OK, we need to wait for some events...
75 get_events = min - sd->nr_events;
76 ret = async_wait(get_events, sd->ahu.user_ring_idx, &sd->ahu);
86 static struct io_u *fio_syslet_event(struct thread_data *td, int event)
88 struct syslet_data *sd = td->io_ops->data;
90 return sd->events[event];
93 static void init_atom(struct syslet_uatom *atom, int nr, void *arg0,
94 void *arg1, void *arg2, void *arg3, void *ret_ptr,
95 unsigned long flags, void *priv)
99 atom->ret_ptr = ret_ptr;
101 atom->arg_ptr[0] = arg0;
102 atom->arg_ptr[1] = arg1;
103 atom->arg_ptr[2] = arg2;
104 atom->arg_ptr[3] = arg3;
105 atom->arg_ptr[4] = atom->arg_ptr[5] = NULL;
106 atom->private = priv;
110 * Use seek atom for sync
112 static void fio_syslet_prep_sync(struct io_u *io_u, struct fio_file *f)
114 init_atom(&io_u->req.atom, __NR_fsync, &f->fd, NULL, NULL, NULL,
115 &io_u->req.ret, 0, io_u);
118 static void fio_syslet_prep_rw(struct io_u *io_u, struct fio_file *f)
125 if (io_u->ddir == DDIR_READ)
130 init_atom(&io_u->req.atom, nr, &f->fd, &io_u->xfer_buf,
131 &io_u->xfer_buflen, &io_u->offset, &io_u->req.ret, 0, io_u);
134 static int fio_syslet_prep(struct thread_data fio_unused *td, struct io_u *io_u)
136 struct fio_file *f = io_u->file;
138 if (io_u->ddir == DDIR_SYNC)
139 fio_syslet_prep_sync(io_u, f);
141 fio_syslet_prep_rw(io_u, f);
146 static void cachemiss_thread_start(void)
152 #define THREAD_STACK_SIZE (16384)
154 static unsigned long thread_stack_alloc()
156 return (unsigned long)malloc(THREAD_STACK_SIZE) + THREAD_STACK_SIZE;
159 static int fio_syslet_queue(struct thread_data *td, struct io_u *io_u)
161 struct syslet_data *sd = td->io_ops->data;
162 struct syslet_uatom *done;
165 if (!sd->ahu.new_thread_stack)
166 sd->ahu.new_thread_stack = thread_stack_alloc();
169 * On sync completion, the atom is returned. So on NULL return
170 * it's queued asynchronously.
172 done = async_exec(&io_u->req.atom, &sd->ahu);
181 if (ret != (long) io_u->xfer_buflen) {
183 io_u->resid = io_u->xfer_buflen - ret;
185 return FIO_Q_COMPLETED;
190 assert(sd->nr_events < td->iodepth);
194 return FIO_Q_COMPLETED;
197 static int async_head_init(struct syslet_data *sd, unsigned int depth)
199 unsigned long ring_size;
201 memset(&sd->ahu, 0, sizeof(struct async_head_user));
203 ring_size = sizeof(struct syslet_uatom *) * depth;
204 sd->ring = malloc(ring_size);
205 memset(sd->ring, 0, ring_size);
207 sd->ahu.user_ring_idx = 0;
208 sd->ahu.completion_ring = sd->ring;
209 sd->ahu.ring_size_bytes = ring_size;
210 sd->ahu.head_stack = thread_stack_alloc();
211 sd->ahu.head_eip = (unsigned long)cachemiss_thread_start;
212 sd->ahu.new_thread_eip = (unsigned long)cachemiss_thread_start;
217 static void async_head_exit(struct syslet_data *sd)
222 static void fio_syslet_cleanup(struct thread_data *td)
224 struct syslet_data *sd = td->io_ops->data;
230 td->io_ops->data = NULL;
234 static int fio_syslet_init(struct thread_data *td)
236 struct syslet_data *sd;
239 sd = malloc(sizeof(*sd));
240 memset(sd, 0, sizeof(*sd));
241 sd->events = malloc(sizeof(struct io_u *) * td->iodepth);
242 memset(sd->events, 0, sizeof(struct io_u *) * td->iodepth);
245 * This will handily fail for kernels where syslet isn't available
247 if (async_head_init(sd, td->iodepth)) {
253 td->io_ops->data = sd;
257 static struct ioengine_ops ioengine = {
259 .version = FIO_IOOPS_VERSION,
260 .init = fio_syslet_init,
261 .prep = fio_syslet_prep,
262 .queue = fio_syslet_queue,
263 .getevents = fio_syslet_getevents,
264 .event = fio_syslet_event,
265 .cleanup = fio_syslet_cleanup,
268 #else /* FIO_HAVE_SYSLET */
271 * When we have a proper configure system in place, we simply wont build
272 * and install this io engine. For now install a crippled version that
273 * just complains and fails to load.
275 static int fio_syslet_init(struct thread_data fio_unused *td)
277 fprintf(stderr, "fio: syslet not available\n");
281 static struct ioengine_ops ioengine = {
283 .version = FIO_IOOPS_VERSION,
284 .init = fio_syslet_init,
287 #endif /* FIO_HAVE_SYSLET */
289 static void fio_init fio_syslet_register(void)
291 register_ioengine(&ioengine);
294 static void fio_exit fio_syslet_unregister(void)
296 unregister_ioengine(&ioengine);