diff --git a/src/backend/storage/aio/aio.c b/src/backend/storage/aio/aio.c
index c64d815ebd1..24fffa6fa76 100644
--- a/src/backend/storage/aio/aio.c
+++ b/src/backend/storage/aio/aio.c
@@ -668,6 +668,7 @@ pgaio_io_reclaim(PgAioHandle *ioh)
 	Assert(ioh->owner_procno == MyProcNumber);
 	Assert(ioh->state != PGAIO_HS_IDLE);
 
+fprintf(stderr, "!!!pgaio_io_reclaim [%d]| ioh: %p, ioh->op: %d, ioh->state: %d, ioh->result: %d, ioh->num_callbacks: %d, ioh->generation: %llu\n", getpid(), ioh, ioh->op, ioh->state, ioh->result, ioh->num_callbacks, ioh->generation);
 	/* see comment in function header */
 	HOLD_INTERRUPTS();
 
@@ -740,6 +741,7 @@ pgaio_io_reclaim(PgAioHandle *ioh)
 	dclist_push_head(&pgaio_my_backend->idle_ios, &ioh->node);
 
 	RESUME_INTERRUPTS();
+fprintf(stderr, "!!!pgaio_io_reclaim [%d]| ioh: %p, ioh->op: %d, ioh->generation: %llu\n", getpid(), ioh, ioh->op, ioh->generation);
 }
 
 /*
diff --git a/src/backend/storage/aio/aio_io.c b/src/backend/storage/aio/aio_io.c
index 00e176135a6..f802af81963 100644
--- a/src/backend/storage/aio/aio_io.c
+++ b/src/backend/storage/aio/aio_io.c
@@ -85,6 +85,7 @@ pgaio_io_start_readv(PgAioHandle *ioh,
 	ioh->op_data.read.iov_length = iovcnt;
 
 	pgaio_io_stage(ioh, PGAIO_OP_READV);
+fprintf(stderr, "!!!pgaio_io_start_readv [%d]| ioh: %p, ioh->op: %d, ioh->generation: %llu\n", getpid(), ioh, ioh->op, ioh->generation);
 }
 
 void
@@ -158,6 +159,8 @@ pgaio_io_before_start(PgAioHandle *ioh)
 	Assert(ioh->state == PGAIO_HS_HANDED_OUT);
 	Assert(pgaio_my_backend->handed_out_io == ioh);
 	Assert(pgaio_io_has_target(ioh));
+if (ioh->op != PGAIO_OP_INVALID) elog(LOG, "!!!pgaio_io_before_start| ioh: %p, ioh->op: %d, ioh->state: %d, ioh->result: %d, ioh->num_callbacks: %d, ioh->generation: %llu", ioh, ioh->op, ioh->state, ioh->result, ioh->num_callbacks, ioh->generation);
+
 	Assert(ioh->op == PGAIO_OP_INVALID);
 
 	/*
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index f93131a645e..e48975452f8 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -67,6 +67,7 @@
 #include "utils/resowner.h"
 #include "utils/timestamp.h"
 
+#include "storage/aio_internal.h"
 
 /* Note: these two macros only work on shared buffers, not local ones! */
 #define BufHdrGetBlock(bufHdr)	((Block) (BufferBlocks + ((Size) (bufHdr)->buf_id) * BLCKSZ))
@@ -1855,7 +1856,10 @@ AsyncReadBuffers(ReadBuffersOperation *operation, int *nblocks_progress)
 		pgaio_submit_staged();
 
 		ioh = pgaio_io_acquire(CurrentResourceOwner, &operation->io_return);
+fprintf(stderr, "!!!AsyncReadBuffers [%d] (2)| blocknum: %d, ioh: %p, ioh->op: %d, ioh->state: %d, ioh->result: %d, ioh->num_callbacks: %d, ioh->generation: %llu\n", getpid(), blocknum, ioh, ((PgAioHandle *)ioh)->op, ((PgAioHandle *)ioh)->state, ((PgAioHandle *)ioh)->result, ((PgAioHandle *)ioh)->num_callbacks, ((PgAioHandle *)ioh)->generation);
 	}
+else
+fprintf(stderr, "!!!AsyncReadBuffers [%d] (1)| blocknum: %d, ioh: %p, ioh->op: %d, ioh->state: %d, ioh->result: %d, ioh->num_callbacks: %d, ioh->generation: %llu\n", getpid(), blocknum, ioh, ((PgAioHandle *)ioh)->op, ((PgAioHandle *)ioh)->state, ((PgAioHandle *)ioh)->result, ((PgAioHandle *)ioh)->num_callbacks, ((PgAioHandle *)ioh)->generation);
 
 	/*
 	 * Check if we can start IO on the first to-be-read buffer.
diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 1c11750ac1d..1135d6dc399 100644
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -712,7 +712,7 @@ sub init
 		print $conf "wal_log_hints = on\n";
 		print $conf "hot_standby = on\n";
 		# conservative settings to ensure we can run multiple postmasters:
-		print $conf "shared_buffers = 1MB\n";
+		print $conf "shared_buffers = 512kB\n";
 		print $conf "max_connections = 10\n";
 		# limit disk space consumption, too:
 		print $conf "max_wal_size = 128MB\n";