[PATCH 1/2] Respect iodepth_batch_complete=0 in main loop

[PATCH 1/2] Respect iodepth_batch_complete=0 in main loop

[Dan Ehrenberg]

If the iodepth_batch_complete is 0, then even if the queue is full,
we still don't make min_events be 1 in the main loop. Instead, poll
in a non-blocking way until a result is found.

Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
---
 fio.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fio.c b/fio.c
index 120431e..7396421 100644
--- a/fio.c
+++ b/fio.c
@@ -557,7 +557,7 @@ sync_done:
 		if (full || !td->o.iodepth_batch_complete) {
 			min_events = min(td->o.iodepth_batch_complete,
 					 td->cur_depth);
-			if (full && !min_events)
+			if (full && !min_events && td->o.iodepth_batch_complete != 0)
 				min_events = 1;
 
 			do {
@@ -719,7 +719,7 @@ sync_done:
 		if (full || !td->o.iodepth_batch_complete) {
 			min_evts = min(td->o.iodepth_batch_complete,
 					td->cur_depth);
-			if (full && !min_evts)
+			if (full && !min_evts && td->o.iodepth_batch_complete != 0)
 				min_evts = 1;
 
 			if (__should_check_rate(td, 0) ||
-- 
1.7.3.1

[PATCH 2/2] Libaio engine support for iodepth_batch_complete=0

[Dan Ehrenberg]

Previously, even if iodepth_batch_complete=0, the libaio engine
passed in non-zero values for the min_nr value for io_getevents.
This patch makes min_nr always 0 if iodepth_batch_complete == 0,
and if multiple events are required at a higher level, then
we poll io_getevents multiple times for the events.

Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
---
 engines/libaio.c |   22 +++++++++-------------
 1 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/engines/libaio.c b/engines/libaio.c
index 439cd24..c837ab6 100644
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -62,22 +62,18 @@ static int fio_libaio_getevents(struct thread_data *td, unsigned int min,
 				unsigned int max, struct timespec *t)
 {
 	struct libaio_data *ld = td->io_ops->data;
-	int r;
+	unsigned actual_min = td->o.iodepth_batch_complete == 0 ? 0 : min;
+	int r, events = 0;
 
 	do {
-		r = io_getevents(ld->aio_ctx, min, max, ld->aio_events, t);
-		if (r >= (int) min)
-			break;
-		else if (r == -EAGAIN) {
+		r = io_getevents(ld->aio_ctx, actual_min, max, ld->aio_events + events, t);
+		if (r >= 0)
+			events += r;
+		else if (r == -EAGAIN)
 			usleep(100);
-			continue;
-		} else if (r == -EINTR)
-			continue;
-		else if (r != 0)
-			break;
-	} while (1);
+	} while (events < min);
 
-	return r;
+	return r < 0 ? r : events;
 }
 
 static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u)
-- 
1.7.3.1

Re: [PATCH 1/2] Respect iodepth_batch_complete=0 in main loop

[Jens Axboe]

On 2011-07-20 23:11, Dan Ehrenberg wrote:
> If the iodepth_batch_complete is 0, then even if the queue is full,
> we still don't make min_events be 1 in the main loop. Instead, poll
> in a non-blocking way until a result is found.

Thanks, applied 1+2.

-- 
Jens Axboe