Libaio engine support for iodepth_batch_complete=0

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>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/engines/libaio.c b/engines/libaio.c
index 439cd242dd9e0aab6df2ad65cda1daba35ee0140..c837ab6bb9e4e9af10553bff980cc318e7274821 100644 (file)
--- 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)