Re: Non-reproducible AIO failure

With this two additional changes:

diff --git a/src/backend/storage/aio/aio.c b/src/backend/storage/aio/aio.c
index 6c6c0a908e2..6dd2816bea9 100644
--- a/src/backend/storage/aio/aio.c
+++ b/src/backend/storage/aio/aio.c
@@ -538,6 +538,9 @@ pgaio_io_process_completion(PgAioHandle *ioh, int 
result)

         pgaio_io_update_state(ioh, PGAIO_HS_COMPLETED_SHARED);

+       /* ensure the state update is visible before we broadcast 
condition variable */
+       pg_write_barrier();
+
         /* condition variable broadcast ensures state is visible before 
wakeup */
         ConditionVariableBroadcast(&ioh->cv);

bool only_running);
diff --git a/src/include/storage/aio_internal.h 
b/src/include/storage/aio_internal.h
index 2d37a243abe..0a2bb109696 100644
--- a/src/include/storage/aio_internal.h
+++ b/src/include/storage/aio_internal.h
@@ -96,13 +96,13 @@ struct ResourceOwnerData;
  struct PgAioHandle
  {
         /* all state updates should go through pgaio_io_update_state() */
-       PgAioHandleState state:8;
+       uint8           state;

         /* what are we operating on */
-       PgAioTargetID target:8;
+       uint8           target;

         /* which IO operation */
-       PgAioOp         op:8;
+       uint8           op;

         /* bitfield of PgAioHandleFlags */
         uint8           flags;

the problem is not reproduced at my system within 20000 seconds. I will 
leave it to run during the night.