kvm tools: Increase AIO_MAX to 256

The queue size for virtio_blk is 256 and AIO_MAX is 32, we might be
short of available aio events if guest issues > 32 requests
simultaneously. Following error is observed when guest running stressed
I/O workload.

  Info: disk_image__read error: total=-11

To fix this, let's increase the aio events limit.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/disk/core.c b/tools/kvm/disk/core.c
index 2b482c6a51842557832adce1c12ac4df499d284d..2739dcdb6f8aac65e35e3adc260d3646d65e793a 100644 (file)
--- a/tools/kvm/disk/core.c
+++ b/tools/kvm/disk/core.c
@@ -6,7 +6,7 @@
 #include <sys/eventfd.h>
 #include <sys/poll.h>
 
-#define AIO_MAX 32
+#define AIO_MAX 256
 
 int debug_iodelay;