[fio.git] / engines / syslet-rw.c

/*
 * syslet engine
 *
 * IO engine that does regular pread(2)/pwrite(2) to transfer data, but
 * with syslets to make the execution async.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <asm/unistd.h>

#include "../fio.h"

#ifdef FIO_HAVE_SYSLET

#ifdef __NR_pread64
#define __NR_fio_pread	__NR_pread64
#define __NR_fio_pwrite	__NR_pwrite64
#else
#define __NR_fio_pread	__NR_pread
#define __NR_fio_pwrite	__NR_pwrite
#endif

#define ATOM_TO_IOU(p)	((struct io_u *) (unsigned long) (p))

struct syslet_data {
	struct io_u **events;
	unsigned int nr_events;
	
	struct async_head_user ahu;
	struct syslet_uatom **ring;

	struct syslet_uatom *head, *tail;
};

static void fio_syslet_complete_atom(struct thread_data *td,
				     struct syslet_uatom *atom)
{
	struct syslet_data *sd = td->io_ops->data;
	struct syslet_uatom *last;
	struct io_u *io_u;

	/*
	 * complete from the beginning of the sequence up to (and
	 * including) this atom
	 */
	last = atom;
	io_u = ATOM_TO_IOU(atom);
	atom = io_u->req.head;

	/*
	 * now complete in right order
	 */
	do {
		long ret;

		io_u = ATOM_TO_IOU(atom);
		ret = *(long *) (unsigned long) atom->ret_ptr;
		if (ret >= 0)
			io_u->resid = io_u->xfer_buflen - ret;
		else if (ret < 0)
			io_u->error = ret;

		assert(sd->nr_events < td->o.iodepth);
		sd->events[sd->nr_events++] = io_u;

		if (atom == last)
			break;

		atom = (struct syslet_uatom *) (unsigned long) atom->next;
	} while (1);

	assert(!last->next);
}

/*
 * Inspect the ring to see if we have completed events
 */
static void fio_syslet_complete(struct thread_data *td)
{
	struct syslet_data *sd = td->io_ops->data;

	do {
		struct syslet_uatom *atom;

		atom = sd->ring[sd->ahu.user_ring_idx];
		if (!atom)
			break;

		sd->ring[sd->ahu.user_ring_idx] = NULL;
		if (++sd->ahu.user_ring_idx == td->o.iodepth)
			sd->ahu.user_ring_idx = 0;

		fio_syslet_complete_atom(td, atom);
	} while (1);
}

static int fio_syslet_getevents(struct thread_data *td, int min,
				int fio_unused max,
				struct timespec fio_unused *t)
{
	struct syslet_data *sd = td->io_ops->data;
	long ret;

	do {
		fio_syslet_complete(td);

		/*
		 * do we have enough immediate completions?
		 */
		if (sd->nr_events >= (unsigned int) min)
			break;

		/*
		 * OK, we need to wait for some events...
		 */
		ret = async_wait(1, sd->ahu.user_ring_idx, &sd->ahu);
		if (ret < 0)
			return -errno;
	} while (1);

	ret = sd->nr_events;
	sd->nr_events = 0;
	return ret;
}

static struct io_u *fio_syslet_event(struct thread_data *td, int event)
{
	struct syslet_data *sd = td->io_ops->data;

	return sd->events[event];
}

static void init_atom(struct syslet_uatom *atom, int nr, void *arg0,
		      void *arg1, void *arg2, void *arg3, void *ret_ptr,
		      unsigned long flags, void *priv)
{
	atom->flags = flags;
	atom->nr = nr;
	atom->ret_ptr = (uint64_t) (unsigned long) ret_ptr;
	atom->next = 0;
	atom->arg_ptr[0] = (uint64_t) (unsigned long) arg0;
	atom->arg_ptr[1] = (uint64_t) (unsigned long) arg1;
	atom->arg_ptr[2] = (uint64_t) (unsigned long) arg2;
	atom->arg_ptr[3] = (uint64_t) (unsigned long) arg3;
	atom->arg_ptr[4] = 0;
	atom->arg_ptr[5] = 0;
	atom->private = (uint64_t) (unsigned long) priv;
}

/*
 * Use seek atom for sync
 */
static void fio_syslet_prep_sync(struct io_u *io_u, struct fio_file *f)
{
	init_atom(&io_u->req.atom, __NR_fsync, &f->fd, NULL, NULL, NULL,
		  &io_u->req.ret, 0, io_u);
}

static void fio_syslet_prep_rw(struct io_u *io_u, struct fio_file *f)
{
	int nr;

	/*
	 * prepare rw
	 */
	if (io_u->ddir == DDIR_READ)
		nr = __NR_fio_pread;
	else
		nr = __NR_fio_pwrite;

	init_atom(&io_u->req.atom, nr, &f->fd, &io_u->xfer_buf,
		  &io_u->xfer_buflen, &io_u->offset, &io_u->req.ret, 0, io_u);
}

static int fio_syslet_prep(struct thread_data fio_unused *td, struct io_u *io_u)
{
	struct fio_file *f = io_u->file;

	if (io_u->ddir == DDIR_SYNC)
		fio_syslet_prep_sync(io_u, f);
	else
		fio_syslet_prep_rw(io_u, f);

	return 0;
}

static void cachemiss_thread_start(void)
{
	while (1)
		async_thread(NULL, NULL);
}

#define THREAD_STACK_SIZE (16384)

static unsigned long thread_stack_alloc()
{
	return (unsigned long) malloc(THREAD_STACK_SIZE) + THREAD_STACK_SIZE;
}

static void fio_syslet_queued(struct thread_data *td, struct syslet_data *sd)
{
	struct syslet_uatom *atom;
	struct timeval now;

	fio_gettime(&now, NULL);

	atom = sd->head;
	while (atom) {
		struct io_u *io_u = ATOM_TO_IOU(atom);

		memcpy(&io_u->issue_time, &now, sizeof(now));
		io_u_queued(td, io_u);
		atom = (struct syslet_uatom *) (unsigned long) atom->next;
	}
}

static int fio_syslet_commit(struct thread_data *td)
{
	struct syslet_data *sd = td->io_ops->data;
	struct syslet_uatom *done;

	if (!sd->head)
		return 0;

	assert(!sd->tail->next);

	if (!sd->ahu.new_thread_stack)
		sd->ahu.new_thread_stack = thread_stack_alloc();

	fio_syslet_queued(td, sd);

	/*
	 * On sync completion, the atom is returned. So on NULL return
	 * it's queued asynchronously.
	 */
	done = async_exec(sd->head, &sd->ahu);

	if (done == (void *) -1) {
		log_err("fio: syslets don't appear to work\n");
		return -1;
	}

	sd->head = sd->tail = NULL;

	if (done)
		fio_syslet_complete_atom(td, done);

	return 0;
}

static int fio_syslet_queue(struct thread_data *td, struct io_u *io_u)
{
	struct syslet_data *sd = td->io_ops->data;

	fio_ro_check(td, io_u);

	if (sd->tail) {
		sd->tail->next = (uint64_t) (unsigned long) &io_u->req.atom;
		sd->tail = &io_u->req.atom;
	} else
		sd->head = sd->tail = (struct syslet_uatom *)&io_u->req.atom;

	io_u->req.head = sd->head;
	return FIO_Q_QUEUED;
}

static int async_head_init(struct syslet_data *sd, unsigned int depth)
{
	unsigned long ring_size;

	memset(&sd->ahu, 0, sizeof(struct async_head_user));

	ring_size = sizeof(struct syslet_uatom *) * depth;
	sd->ring = malloc(ring_size);
	memset(sd->ring, 0, ring_size);

	sd->ahu.user_ring_idx = 0;
	sd->ahu.completion_ring_ptr = (uint64_t) (unsigned long) sd->ring;
	sd->ahu.ring_size_bytes = ring_size;
	sd->ahu.head_stack = thread_stack_alloc();
	sd->ahu.head_ip = (uint64_t) (unsigned long) cachemiss_thread_start;
	sd->ahu.new_thread_ip = (uint64_t) (unsigned long) cachemiss_thread_start;
	sd->ahu.new_thread_stack = thread_stack_alloc();

	return 0;
}

static void async_head_exit(struct syslet_data *sd)
{
	free(sd->ring);
}

static int check_syslet_support(struct syslet_data *sd)
{
	struct syslet_uatom atom;
	void *ret;

	init_atom(&atom, __NR_getpid, NULL, NULL, NULL, NULL, NULL, 0, NULL);
	ret = async_exec(&atom, &sd->ahu);
	if (ret == (void *) -1)
		return 1;

	return 0;
}

static void fio_syslet_cleanup(struct thread_data *td)
{
	struct syslet_data *sd = td->io_ops->data;

	if (sd) {
		async_head_exit(sd);
		free(sd->events);
		free(sd);
		td->io_ops->data = NULL;
	}
}

static int fio_syslet_init(struct thread_data *td)
{
	struct syslet_data *sd;

	sd = malloc(sizeof(*sd));
	memset(sd, 0, sizeof(*sd));
	sd->events = malloc(sizeof(struct io_u *) * td->o.iodepth);
	memset(sd->events, 0, sizeof(struct io_u *) * td->o.iodepth);

	/*
	 * This will handily fail for kernels where syslet isn't available
	 */
	if (async_head_init(sd, td->o.iodepth)) {
		free(sd->events);
		free(sd);
		return 1;
	}

	if (check_syslet_support(sd)) {
		log_err("fio: syslets do not appear to work\n");
		free(sd->events);
		free(sd);
		return 1;
	}

	td->io_ops->data = sd;
	return 0;
}

static struct ioengine_ops ioengine = {
	.name		= "syslet-rw",
	.version	= FIO_IOOPS_VERSION,
	.init		= fio_syslet_init,
	.prep		= fio_syslet_prep,
	.queue		= fio_syslet_queue,
	.commit		= fio_syslet_commit,
	.getevents	= fio_syslet_getevents,
	.event		= fio_syslet_event,
	.cleanup	= fio_syslet_cleanup,
	.open_file	= generic_open_file,
	.close_file	= generic_close_file,
};

#else /* FIO_HAVE_SYSLET */

/*
 * When we have a proper configure system in place, we simply wont build
 * and install this io engine. For now install a crippled version that
 * just complains and fails to load.
 */
static int fio_syslet_init(struct thread_data fio_unused *td)
{
	fprintf(stderr, "fio: syslet not available\n");
	return 1;
}

static struct ioengine_ops ioengine = {
	.name		= "syslet-rw",
	.version	= FIO_IOOPS_VERSION,
	.init		= fio_syslet_init,
};

#endif /* FIO_HAVE_SYSLET */

static void fio_init fio_syslet_register(void)
{
	register_ioengine(&ioengine);
}

static void fio_exit fio_syslet_unregister(void)
{
	unregister_ioengine(&ioengine);
}
Commit	Line	Data
a4f4fdd7	1	/*
da751ca9 JA	2	* syslet engine
	3	*
	4	* IO engine that does regular pread(2)/pwrite(2) to transfer data, but
	5	* with syslets to make the execution async.
a4f4fdd7 JA	6	*
	7	*/
	8	#include <stdio.h>
	9	#include <stdlib.h>
	10	#include <unistd.h>
	11	#include <errno.h>
	12	#include <assert.h>
b8846354	13	#include <asm/unistd.h>
a4f4fdd7 JA	14
a4f4fdd7 JA	15	#include "../fio.h"
a4f4fdd7 JA	16
	17	#ifdef FIO_HAVE_SYSLET
	18
1760e679 JA	19	#ifdef __NR_pread64
	20	#define __NR_fio_pread __NR_pread64
	21	#define __NR_fio_pwrite __NR_pwrite64
	22	#else
	23	#define __NR_fio_pread __NR_pread
	24	#define __NR_fio_pwrite __NR_pwrite
	25	#endif
	26
67f5b27e JA	27	#define ATOM_TO_IOU(p) ((struct io_u *) (unsigned long) (p))
67f5b27e JA	28
a4f4fdd7 JA	29	struct syslet_data {
	30	struct io_u **events;
	31	unsigned int nr_events;
	32
bf0dc8fa	33	struct async_head_user ahu;
a4f4fdd7	34	struct syslet_uatom **ring;
9ff9de69 JA	35
9ff9de69 JA	36	struct syslet_uatom head, tail;
a4f4fdd7 JA	37	};
a4f4fdd7 JA	38
9ff9de69 JA	39	static void fio_syslet_complete_atom(struct thread_data *td,
	40	struct syslet_uatom *atom)
	41	{
	42	struct syslet_data *sd = td->io_ops->data;
5b38ee84	43	struct syslet_uatom *last;
9ff9de69	44	struct io_u *io_u;
9ff9de69 JA	45
9ff9de69 JA	46	/*
5b38ee84 JA	47	* complete from the beginning of the sequence up to (and
5b38ee84 JA	48	* including) this atom
9ff9de69	49	*/
5b38ee84	50	last = atom;
67f5b27e	51	io_u = ATOM_TO_IOU(atom);
5b38ee84	52	atom = io_u->req.head;
9ff9de69 JA	53
	54	/*
	55	* now complete in right order
	56	*/
5b38ee84	57	do {
9ff9de69 JA	58	long ret;
9ff9de69 JA	59
67f5b27e JA	60	io_u = ATOM_TO_IOU(atom);
67f5b27e JA	61	ret = (long ) (unsigned long) atom->ret_ptr;
e2e67912	62	if (ret >= 0)
9ff9de69 JA	63	io_u->resid = io_u->xfer_buflen - ret;
	64	else if (ret < 0)
	65	io_u->error = ret;
	66
2dc1bbeb	67	assert(sd->nr_events < td->o.iodepth);
9ff9de69	68	sd->events[sd->nr_events++] = io_u;
9ff9de69	69
5b38ee84 JA	70	if (atom == last)
5b38ee84 JA	71	break;
9ff9de69	72
67f5b27e	73	atom = (struct syslet_uatom *) (unsigned long) atom->next;
5b38ee84 JA	74	} while (1);
	75
	76	assert(!last->next);
9ff9de69 JA	77	}
9ff9de69 JA	78
a4f4fdd7 JA	79	/*
	80	* Inspect the ring to see if we have completed events
	81	*/
	82	static void fio_syslet_complete(struct thread_data *td)
	83	{
	84	struct syslet_data *sd = td->io_ops->data;
	85
	86	do {
	87	struct syslet_uatom *atom;
a4f4fdd7	88
bf0dc8fa	89	atom = sd->ring[sd->ahu.user_ring_idx];
a4f4fdd7 JA	90	if (!atom)
	91	break;
	92
bf0dc8fa	93	sd->ring[sd->ahu.user_ring_idx] = NULL;
2dc1bbeb	94	if (++sd->ahu.user_ring_idx == td->o.iodepth)
bf0dc8fa	95	sd->ahu.user_ring_idx = 0;
a4f4fdd7	96
9ff9de69	97	fio_syslet_complete_atom(td, atom);
a4f4fdd7 JA	98	} while (1);
	99	}
	100
	101	static int fio_syslet_getevents(struct thread_data *td, int min,
	102	int fio_unused max,
	103	struct timespec fio_unused *t)
	104	{
	105	struct syslet_data *sd = td->io_ops->data;
a4f4fdd7 JA	106	long ret;
	107
	108	do {
	109	fio_syslet_complete(td);
	110
	111	/*
	112	* do we have enough immediate completions?
	113	*/
	114	if (sd->nr_events >= (unsigned int) min)
	115	break;
	116
	117	/*
	118	* OK, we need to wait for some events...
	119	*/
9ff9de69	120	ret = async_wait(1, sd->ahu.user_ring_idx, &sd->ahu);
a4f4fdd7	121	if (ret < 0)
e49499f8	122	return -errno;
a4f4fdd7 JA	123	} while (1);
	124
	125	ret = sd->nr_events;
	126	sd->nr_events = 0;
	127	return ret;
	128	}
	129
	130	static struct io_u fio_syslet_event(struct thread_data td, int event)
	131	{
	132	struct syslet_data *sd = td->io_ops->data;
	133
	134	return sd->events[event];
	135	}
	136
	137	static void init_atom(struct syslet_uatom atom, int nr, void arg0,
a2e1b08a JA	138	void arg1, void arg2, void arg3, void ret_ptr,
a2e1b08a JA	139	unsigned long flags, void *priv)
a4f4fdd7 JA	140	{
	141	atom->flags = flags;
	142	atom->nr = nr;
67f5b27e	143	atom->ret_ptr = (uint64_t) (unsigned long) ret_ptr;
1d79a6d1	144	atom->next = 0;
67f5b27e JA	145	atom->arg_ptr[0] = (uint64_t) (unsigned long) arg0;
	146	atom->arg_ptr[1] = (uint64_t) (unsigned long) arg1;
	147	atom->arg_ptr[2] = (uint64_t) (unsigned long) arg2;
	148	atom->arg_ptr[3] = (uint64_t) (unsigned long) arg3;
1d79a6d1 ZB	149	atom->arg_ptr[4] = 0;
1d79a6d1 ZB	150	atom->arg_ptr[5] = 0;
67f5b27e	151	atom->private = (uint64_t) (unsigned long) priv;
a4f4fdd7 JA	152	}
	153
	154	/*
	155	* Use seek atom for sync
	156	*/
	157	static void fio_syslet_prep_sync(struct io_u io_u, struct fio_file f)
	158	{
a2e1b08a	159	init_atom(&io_u->req.atom, __NR_fsync, &f->fd, NULL, NULL, NULL,
7d44a745	160	&io_u->req.ret, 0, io_u);
a4f4fdd7 JA	161	}
	162
	163	static void fio_syslet_prep_rw(struct io_u io_u, struct fio_file f)
	164	{
	165	int nr;
	166
a4f4fdd7 JA	167	/*
	168	* prepare rw
	169	*/
	170	if (io_u->ddir == DDIR_READ)
1760e679	171	nr = __NR_fio_pread;
a4f4fdd7	172	else
1760e679	173	nr = __NR_fio_pwrite;
a4f4fdd7	174
a2e1b08a	175	init_atom(&io_u->req.atom, nr, &f->fd, &io_u->xfer_buf,
7d44a745	176	&io_u->xfer_buflen, &io_u->offset, &io_u->req.ret, 0, io_u);
a4f4fdd7 JA	177	}
	178
	179	static int fio_syslet_prep(struct thread_data fio_unused td, struct io_u io_u)
	180	{
	181	struct fio_file *f = io_u->file;
	182
	183	if (io_u->ddir == DDIR_SYNC)
	184	fio_syslet_prep_sync(io_u, f);
	185	else
	186	fio_syslet_prep_rw(io_u, f);
	187
	188	return 0;
	189	}
	190
bf0dc8fa IM	191	static void cachemiss_thread_start(void)
	192	{
	193	while (1)
7756b0d0	194	async_thread(NULL, NULL);
bf0dc8fa IM	195	}
	196
	197	#define THREAD_STACK_SIZE (16384)
	198
	199	static unsigned long thread_stack_alloc()
	200	{
5b38ee84	201	return (unsigned long) malloc(THREAD_STACK_SIZE) + THREAD_STACK_SIZE;
bf0dc8fa IM	202	}
bf0dc8fa IM	203
a0a930ef JA	204	static void fio_syslet_queued(struct thread_data td, struct syslet_data sd)
	205	{
	206	struct syslet_uatom *atom;
	207	struct timeval now;
	208
	209	fio_gettime(&now, NULL);
	210
	211	atom = sd->head;
	212	while (atom) {
67f5b27e	213	struct io_u *io_u = ATOM_TO_IOU(atom);
a0a930ef JA	214
	215	memcpy(&io_u->issue_time, &now, sizeof(now));
	216	io_u_queued(td, io_u);
67f5b27e	217	atom = (struct syslet_uatom *) (unsigned long) atom->next;
a0a930ef JA	218	}
	219	}
	220
9ff9de69	221	static int fio_syslet_commit(struct thread_data *td)
a4f4fdd7 JA	222	{
a4f4fdd7 JA	223	struct syslet_data *sd = td->io_ops->data;
bf0dc8fa	224	struct syslet_uatom *done;
9ff9de69 JA	225
	226	if (!sd->head)
	227	return 0;
a4f4fdd7	228
5b38ee84 JA	229	assert(!sd->tail->next);
5b38ee84 JA	230
bf0dc8fa IM	231	if (!sd->ahu.new_thread_stack)
	232	sd->ahu.new_thread_stack = thread_stack_alloc();
	233
a0a930ef JA	234	fio_syslet_queued(td, sd);
a0a930ef JA	235
7d44a745 JA	236	/*
	237	* On sync completion, the atom is returned. So on NULL return
	238	* it's queued asynchronously.
	239	*/
9ff9de69	240	done = async_exec(sd->head, &sd->ahu);
bf0dc8fa	241
76f58b92 JA	242	if (done == (void *) -1) {
	243	log_err("fio: syslets don't appear to work\n");
	244	return -1;
	245	}
	246
9ff9de69	247	sd->head = sd->tail = NULL;
a4f4fdd7	248
9ff9de69 JA	249	if (done)
9ff9de69 JA	250	fio_syslet_complete_atom(td, done);
a4f4fdd7	251
9ff9de69 JA	252	return 0;
	253	}
	254
	255	static int fio_syslet_queue(struct thread_data td, struct io_u io_u)
	256	{
	257	struct syslet_data *sd = td->io_ops->data;
bf0dc8fa	258
7101d9c2 JA	259	fio_ro_check(td, io_u);
7101d9c2 JA	260
9ff9de69	261	if (sd->tail) {
67f5b27e	262	sd->tail->next = (uint64_t) (unsigned long) &io_u->req.atom;
9ff9de69 JA	263	sd->tail = &io_u->req.atom;
9ff9de69 JA	264	} else
1d79a6d1	265	sd->head = sd->tail = (struct syslet_uatom *)&io_u->req.atom;
a4f4fdd7	266
5b38ee84	267	io_u->req.head = sd->head;
9ff9de69	268	return FIO_Q_QUEUED;
a4f4fdd7 JA	269	}
a4f4fdd7 JA	270
db64e9bc	271	static int async_head_init(struct syslet_data *sd, unsigned int depth)
a4f4fdd7	272	{
a4f4fdd7 JA	273	unsigned long ring_size;
a4f4fdd7 JA	274
bf0dc8fa	275	memset(&sd->ahu, 0, sizeof(struct async_head_user));
2ca50be4	276
a4f4fdd7 JA	277	ring_size = sizeof(struct syslet_uatom ) depth;
	278	sd->ring = malloc(ring_size);
	279	memset(sd->ring, 0, ring_size);
	280
bf0dc8fa	281	sd->ahu.user_ring_idx = 0;
67f5b27e	282	sd->ahu.completion_ring_ptr = (uint64_t) (unsigned long) sd->ring;
bf0dc8fa IM	283	sd->ahu.ring_size_bytes = ring_size;
bf0dc8fa IM	284	sd->ahu.head_stack = thread_stack_alloc();
67f5b27e JA	285	sd->ahu.head_ip = (uint64_t) (unsigned long) cachemiss_thread_start;
67f5b27e JA	286	sd->ahu.new_thread_ip = (uint64_t) (unsigned long) cachemiss_thread_start;
6a117e0c	287	sd->ahu.new_thread_stack = thread_stack_alloc();
db64e9bc JA	288
db64e9bc JA	289	return 0;
a4f4fdd7 JA	290	}
a4f4fdd7 JA	291
2ca50be4	292	static void async_head_exit(struct syslet_data *sd)
a4f4fdd7	293	{
7f059a76	294	free(sd->ring);
a4f4fdd7 JA	295	}
a4f4fdd7 JA	296
76f58b92 JA	297	static int check_syslet_support(struct syslet_data *sd)
	298	{
	299	struct syslet_uatom atom;
	300	void *ret;
	301
	302	init_atom(&atom, __NR_getpid, NULL, NULL, NULL, NULL, NULL, 0, NULL);
b4d8ddac	303	ret = async_exec(&atom, &sd->ahu);
76f58b92 JA	304	if (ret == (void *) -1)
	305	return 1;
	306
	307	return 0;
	308	}
	309
a4f4fdd7 JA	310	static void fio_syslet_cleanup(struct thread_data *td)
	311	{
	312	struct syslet_data *sd = td->io_ops->data;
	313
	314	if (sd) {
2ca50be4	315	async_head_exit(sd);
a4f4fdd7 JA	316	free(sd->events);
	317	free(sd);
	318	td->io_ops->data = NULL;
	319	}
	320	}
	321
	322	static int fio_syslet_init(struct thread_data *td)
	323	{
	324	struct syslet_data *sd;
	325
	326	sd = malloc(sizeof(*sd));
	327	memset(sd, 0, sizeof(*sd));
2dc1bbeb JA	328	sd->events = malloc(sizeof(struct io_u ) td->o.iodepth);
2dc1bbeb JA	329	memset(sd->events, 0, sizeof(struct io_u ) td->o.iodepth);
db64e9bc JA	330
	331	/*
	332	* This will handily fail for kernels where syslet isn't available
	333	*/
2dc1bbeb	334	if (async_head_init(sd, td->o.iodepth)) {
db64e9bc JA	335	free(sd->events);
	336	free(sd);
	337	return 1;
	338	}
	339
76f58b92 JA	340	if (check_syslet_support(sd)) {
	341	log_err("fio: syslets do not appear to work\n");
	342	free(sd->events);
	343	free(sd);
	344	return 1;
	345	}
	346
a4f4fdd7	347	td->io_ops->data = sd;
a4f4fdd7 JA	348	return 0;
	349	}
	350
	351	static struct ioengine_ops ioengine = {
	352	.name = "syslet-rw",
	353	.version = FIO_IOOPS_VERSION,
	354	.init = fio_syslet_init,
	355	.prep = fio_syslet_prep,
	356	.queue = fio_syslet_queue,
9ff9de69	357	.commit = fio_syslet_commit,
a4f4fdd7 JA	358	.getevents = fio_syslet_getevents,
	359	.event = fio_syslet_event,
	360	.cleanup = fio_syslet_cleanup,
b5af8293 JA	361	.open_file = generic_open_file,
b5af8293 JA	362	.close_file = generic_close_file,
a4f4fdd7 JA	363	};
	364
	365	#else /* FIO_HAVE_SYSLET */
	366
	367	/*
	368	* When we have a proper configure system in place, we simply wont build
	369	* and install this io engine. For now install a crippled version that
	370	* just complains and fails to load.
	371	*/
	372	static int fio_syslet_init(struct thread_data fio_unused *td)
	373	{
	374	fprintf(stderr, "fio: syslet not available\n");
	375	return 1;
	376	}
	377
	378	static struct ioengine_ops ioengine = {
	379	.name = "syslet-rw",
	380	.version = FIO_IOOPS_VERSION,
	381	.init = fio_syslet_init,
	382	};
	383
	384	#endif /* FIO_HAVE_SYSLET */
	385
	386	static void fio_init fio_syslet_register(void)
	387	{
	388	register_ioengine(&ioengine);
	389	}
	390
	391	static void fio_exit fio_syslet_unregister(void)
	392	{
	393	unregister_ioengine(&ioengine);
	394	}