X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=engines%2Flibaio.c;h=299798ae8a5a16de1e0b112d2bbf74323eae22b8;hp=d668325f4af34ff8247e777eaf45e9f5e7804172;hb=b2a432bfbb6d;hpb=29df29eaf88958c8741103d2056a4773d4959d9d

diff --git a/engines/libaio.c b/engines/libaio.c
index d668325f..299798ae 100644
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -4,26 +4,53 @@
  * IO engine using the Linux native aio interface.
  *
  */
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
-#include <assert.h>
 #include <libaio.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 
 #include "../fio.h"
+#include "../lib/pow2.h"
+#include "../optgroup.h"
+#include "../lib/memalign.h"
+
+/* Should be defined in newest aio_abi.h */
+#ifndef IOCB_FLAG_IOPRIO
+#define IOCB_FLAG_IOPRIO    (1 << 1)
+#endif
+
+static int fio_libaio_commit(struct thread_data *td);
+static int fio_libaio_init(struct thread_data *td);
 
 struct libaio_data {
 	io_context_t aio_ctx;
 	struct io_event *aio_events;
 	struct iocb **iocbs;
 	struct io_u **io_us;
-	int iocbs_nr;
+
+	struct io_u **io_u_index;
+
+	/*
+	 * Basic ring buffer. 'head' is incremented in _queue(), and
+	 * 'tail' is incremented in _commit(). We keep 'queued' so
+	 * that we know if the ring is full or empty, when
+	 * 'head' == 'tail'. 'entries' is the ring size, and
+	 * 'is_pow2' is just an optimization to use AND instead of
+	 * modulus to get the remainder on ring increment.
+	 */
+	int is_pow2;
+	unsigned int entries;
+	unsigned int queued;
+	unsigned int head;
+	unsigned int tail;
 };
 
 struct libaio_options {
-	struct thread_data *td;
+	void *pad;
 	unsigned int userspace_reap;
+	unsigned int cmdprio_percentage;
 };
 
 static struct fio_option options[] = {
@@ -33,30 +60,72 @@ static struct fio_option options[] = {
 		.type	= FIO_OPT_STR_SET,
 		.off1	= offsetof(struct libaio_options, userspace_reap),
 		.help	= "Use alternative user-space reap implementation",
-		.category = FIO_OPT_C_IO,
+		.category = FIO_OPT_C_ENGINE,
+		.group	= FIO_OPT_G_LIBAIO,
 	},
+#ifdef FIO_HAVE_IOPRIO_CLASS
+	{
+		.name	= "cmdprio_percentage",
+		.lname	= "high priority percentage",
+		.type	= FIO_OPT_INT,
+		.off1	= offsetof(struct libaio_options, cmdprio_percentage),
+		.minval	= 1,
+		.maxval	= 100,
+		.help	= "Send high priority I/O this percentage of the time",
+		.category = FIO_OPT_C_ENGINE,
+		.group	= FIO_OPT_G_LIBAIO,
+	},
+#else
+	{
+		.name	= "cmdprio_percentage",
+		.lname	= "high priority percentage",
+		.type	= FIO_OPT_UNSUPPORTED,
+		.help	= "Your platform does not support I/O priority classes",
+	},
+#endif
 	{
 		.name	= NULL,
 	},
 };
 
+static inline void ring_inc(struct libaio_data *ld, unsigned int *val,
+			    unsigned int add)
+{
+	if (ld->is_pow2)
+		*val = (*val + add) & (ld->entries - 1);
+	else
+		*val = (*val + add) % ld->entries;
+}
+
 static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u)
 {
 	struct fio_file *f = io_u->file;
+	struct iocb *iocb = &io_u->iocb;
 
-	if (io_u->ddir == DDIR_READ)
-		io_prep_pread(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
-	else if (io_u->ddir == DDIR_WRITE)
-		io_prep_pwrite(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
-	else if (ddir_sync(io_u->ddir))
-		io_prep_fsync(&io_u->iocb, f->fd);
+	if (io_u->ddir == DDIR_READ) {
+		io_prep_pread(iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
+	} else if (io_u->ddir == DDIR_WRITE) {
+		io_prep_pwrite(iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
+	} else if (ddir_sync(io_u->ddir))
+		io_prep_fsync(iocb, f->fd);
 
 	return 0;
 }
 
+static void fio_libaio_prio_prep(struct thread_data *td, struct io_u *io_u)
+{
+	struct libaio_options *o = td->eo;
+	if (rand_between(&td->prio_state, 0, 99) < o->cmdprio_percentage) {
+		io_u->iocb.aio_reqprio = IOPRIO_CLASS_RT << IOPRIO_CLASS_SHIFT;
+		io_u->iocb.u.c.flags |= IOCB_FLAG_IOPRIO;
+		io_u->flags |= IO_U_F_PRIORITY;
+	}
+	return;
+}
+
 static struct io_u *fio_libaio_event(struct thread_data *td, int event)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
 	struct io_event *ev;
 	struct io_u *io_u;
 
@@ -116,13 +185,19 @@ static int user_io_getevents(io_context_t aio_ctx, unsigned int max,
 }
 
 static int fio_libaio_getevents(struct thread_data *td, unsigned int min,
-				unsigned int max, struct timespec *t)
+				unsigned int max, const struct timespec *t)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
 	struct libaio_options *o = td->eo;
-	unsigned actual_min = td->o.iodepth_batch_complete == 0 ? 0 : min;
+	unsigned actual_min = td->o.iodepth_batch_complete_min == 0 ? 0 : min;
+	struct timespec __lt, *lt = NULL;
 	int r, events = 0;
 
+	if (t) {
+		__lt = *t;
+		lt = &__lt;
+	}
+
 	do {
 		if (o->userspace_reap == 1
 		    && actual_min == 0
@@ -132,24 +207,30 @@ static int fio_libaio_getevents(struct thread_data *td, unsigned int min,
 				ld->aio_events + events);
 		} else {
 			r = io_getevents(ld->aio_ctx, actual_min,
-				max, ld->aio_events + events, t);
+				max, ld->aio_events + events, lt);
 		}
-		if (r >= 0)
+		if (r > 0)
 			events += r;
-		else if (r == -EAGAIN)
-			usleep(100);
+		else if ((min && r == 0) || r == -EAGAIN) {
+			fio_libaio_commit(td);
+			if (actual_min)
+				usleep(10);
+		} else if (r != -EINTR)
+			break;
 	} while (events < min);
 
 	return r < 0 ? r : events;
 }
 
-static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u)
+static enum fio_q_status fio_libaio_queue(struct thread_data *td,
+					  struct io_u *io_u)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
+	struct libaio_options *o = td->eo;
 
 	fio_ro_check(td, io_u);
 
-	if (ld->iocbs_nr == (int) td->o.iodepth)
+	if (ld->queued == td->o.iodepth)
 		return FIO_Q_BUSY;
 
 	/*
@@ -159,7 +240,7 @@ static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u)
 	 * have pending io, to let fio complete those first.
 	 */
 	if (ddir_sync(io_u->ddir)) {
-		if (ld->iocbs_nr)
+		if (ld->queued)
 			return FIO_Q_BUSY;
 
 		do_io_u_sync(td, io_u);
@@ -167,23 +248,29 @@ static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u)
 	}
 
 	if (io_u->ddir == DDIR_TRIM) {
-		if (ld->iocbs_nr)
+		if (ld->queued)
 			return FIO_Q_BUSY;
 
 		do_io_u_trim(td, io_u);
+		io_u_mark_submit(td, 1);
+		io_u_mark_complete(td, 1);
 		return FIO_Q_COMPLETED;
 	}
 
-	ld->iocbs[ld->iocbs_nr] = &io_u->iocb;
-	ld->io_us[ld->iocbs_nr] = io_u;
-	ld->iocbs_nr++;
+	if (o->cmdprio_percentage)
+		fio_libaio_prio_prep(td, io_u);
+
+	ld->iocbs[ld->head] = &io_u->iocb;
+	ld->io_us[ld->head] = io_u;
+	ring_inc(ld, &ld->head, 1);
+	ld->queued++;
 	return FIO_Q_QUEUED;
 }
 
 static void fio_libaio_queued(struct thread_data *td, struct io_u **io_us,
 			      unsigned int nr)
 {
-	struct timeval now;
+	struct timespec now;
 	unsigned int i;
 
 	if (!fio_fill_issue_time(td))
@@ -201,49 +288,94 @@ static void fio_libaio_queued(struct thread_data *td, struct io_u **io_us,
 
 static int fio_libaio_commit(struct thread_data *td)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
 	struct iocb **iocbs;
 	struct io_u **io_us;
-	int ret;
+	struct timespec ts;
+	int ret, wait_start = 0;
 
-	if (!ld->iocbs_nr)
+	if (!ld->queued)
 		return 0;
 
-	io_us = ld->io_us;
-	iocbs = ld->iocbs;
 	do {
-		ret = io_submit(ld->aio_ctx, ld->iocbs_nr, iocbs);
+		long nr = ld->queued;
+
+		nr = min((unsigned int) nr, ld->entries - ld->tail);
+		io_us = ld->io_us + ld->tail;
+		iocbs = ld->iocbs + ld->tail;
+
+		ret = io_submit(ld->aio_ctx, nr, iocbs);
 		if (ret > 0) {
 			fio_libaio_queued(td, io_us, ret);
 			io_u_mark_submit(td, ret);
-			ld->iocbs_nr -= ret;
-			io_us += ret;
-			iocbs += ret;
+
+			ld->queued -= ret;
+			ring_inc(ld, &ld->tail, ret);
 			ret = 0;
-		} else if (!ret || ret == -EAGAIN || ret == -EINTR) {
+			wait_start = 0;
+		} else if (ret == -EINTR || !ret) {
 			if (!ret)
 				io_u_mark_submit(td, ret);
+			wait_start = 0;
+			continue;
+		} else if (ret == -EAGAIN) {
+			/*
+			 * If we get EAGAIN, we should break out without
+			 * error and let the upper layer reap some
+			 * events for us. If we have no queued IO, we
+			 * must loop here. If we loop for more than 30s,
+			 * just error out, something must be buggy in the
+			 * IO path.
+			 */
+			if (ld->queued) {
+				ret = 0;
+				break;
+			}
+			if (!wait_start) {
+				fio_gettime(&ts, NULL);
+				wait_start = 1;
+			} else if (mtime_since_now(&ts) > 30000) {
+				log_err("fio: aio appears to be stalled, giving up\n");
+				break;
+			}
+			usleep(1);
 			continue;
+		} else if (ret == -ENOMEM) {
+			/*
+			 * If we get -ENOMEM, reap events if we can. If
+			 * we cannot, treat it as a fatal event since there's
+			 * nothing we can do about it.
+			 */
+			if (ld->queued)
+				ret = 0;
+			break;
 		} else
 			break;
-	} while (ld->iocbs_nr);
+	} while (ld->queued);
 
 	return ret;
 }
 
 static int fio_libaio_cancel(struct thread_data *td, struct io_u *io_u)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
 
 	return io_cancel(ld->aio_ctx, &io_u->iocb, ld->aio_events);
 }
 
 static void fio_libaio_cleanup(struct thread_data *td)
 {
-	struct libaio_data *ld = td->io_ops->data;
+	struct libaio_data *ld = td->io_ops_data;
 
 	if (ld) {
-		io_destroy(ld->aio_ctx);
+		/*
+		 * Work-around to avoid huge RCU stalls at exit time. If we
+		 * don't do this here, then it'll be torn down by exit_aio().
+		 * But for that case we can parallellize the freeing, thus
+		 * speeding it up a lot.
+		 */
+		if (!(td->flags & TD_F_CHILD))
+			io_destroy(ld->aio_ctx);
 		free(ld->aio_events);
 		free(ld->iocbs);
 		free(ld->io_us);
@@ -251,46 +383,54 @@ static void fio_libaio_cleanup(struct thread_data *td)
 	}
 }
 
+static int fio_libaio_post_init(struct thread_data *td)
+{
+	struct libaio_data *ld = td->io_ops_data;
+	int err;
+
+	err = io_queue_init(td->o.iodepth, &ld->aio_ctx);
+	if (err) {
+		td_verror(td, -err, "io_queue_init");
+		return 1;
+	}
+
+	return 0;
+}
+
 static int fio_libaio_init(struct thread_data *td)
 {
-	struct libaio_data *ld = malloc(sizeof(*ld));
+	struct libaio_data *ld;
+	struct thread_options *to = &td->o;
 	struct libaio_options *o = td->eo;
-	int err = 0;
 
-	memset(ld, 0, sizeof(*ld));
+	ld = calloc(1, sizeof(*ld));
+
+	ld->entries = td->o.iodepth;
+	ld->is_pow2 = is_power_of_2(ld->entries);
+	ld->aio_events = calloc(ld->entries, sizeof(struct io_event));
+	ld->iocbs = calloc(ld->entries, sizeof(struct iocb *));
+	ld->io_us = calloc(ld->entries, sizeof(struct io_u *));
 
+	td->io_ops_data = ld;
 	/*
-	 * First try passing in 0 for queue depth, since we don't
-	 * care about the user ring. If that fails, the kernel is too old
-	 * and we need the right depth.
+	 * Check for option conflicts
 	 */
-	if (!o->userspace_reap)
-		err = io_queue_init(INT_MAX, &ld->aio_ctx);
-	if (o->userspace_reap || err == -EINVAL)
-		err = io_queue_init(td->o.iodepth, &ld->aio_ctx);
-	if (err) {
-		td_verror(td, -err, "io_queue_init");
-		log_err("fio: check /proc/sys/fs/aio-max-nr\n");
-		free(ld);
+	if ((fio_option_is_set(to, ioprio) || fio_option_is_set(to, ioprio_class)) &&
+			o->cmdprio_percentage != 0) {
+		log_err("%s: cmdprio_percentage option and mutually exclusive "
+				"prio or prioclass option is set, exiting\n", to->name);
+		td_verror(td, EINVAL, "fio_libaio_init");
 		return 1;
 	}
-
-	ld->aio_events = malloc(td->o.iodepth * sizeof(struct io_event));
-	memset(ld->aio_events, 0, td->o.iodepth * sizeof(struct io_event));
-	ld->iocbs = malloc(td->o.iodepth * sizeof(struct iocb *));
-	memset(ld->iocbs, 0, sizeof(struct iocb *));
-	ld->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
-	memset(ld->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
-	ld->iocbs_nr = 0;
-
-	td->io_ops->data = ld;
 	return 0;
 }
 
 static struct ioengine_ops ioengine = {
 	.name			= "libaio",
 	.version		= FIO_IOOPS_VERSION,
+	.flags			= FIO_ASYNCIO_SYNC_TRIM,
 	.init			= fio_libaio_init,
+	.post_init		= fio_libaio_post_init,
 	.prep			= fio_libaio_prep,
 	.queue			= fio_libaio_queue,
 	.commit			= fio_libaio_commit,