Michael Kelley [off-list ref] writes:
From: Vitaly Kuznetsov <vkuznets@redhat.com> Sent: Wednesday, June 12, 2019 3:40 AM
quoted
Maya Nakamura [off-list ref] writes:
quoted
Define the ring buffer size as a constant expression because it should
not depend on the guest page size.
Signed-off-by: Maya Nakamura <redacted>
---
drivers/hid/hid-hyperv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
index d3311d714d35..e8b154fa38e2 100644
--- a/drivers/hid/hid-hyperv.c
+++ b/drivers/hid/hid-hyperv.c
@@ -112,8 +112,8 @@ struct synthhid_input_report {
#pragma pack(pop)
-#define INPUTVSC_SEND_RING_BUFFER_SIZE (10*PAGE_SIZE)
-#define INPUTVSC_RECV_RING_BUFFER_SIZE (10*PAGE_SIZE)
+#define INPUTVSC_SEND_RING_BUFFER_SIZE (40 * 1024)
+#define INPUTVSC_RECV_RING_BUFFER_SIZE (40 * 1024)
My understanding is that this size is pretty arbitrary and as I see you
use it for hyperv-keyboard.c as well. It may make sense to have a
define, something like HYPERV_STD_RINGBUFFER_SIZE.
Yes, the size is pretty arbitrary because it hasn't been important enough
from a memory consumption or performance standpoint to run experiments
to see if a smaller value could be used. That said, I would not want to
link these two devices (keyboard and mouse) by using a shared ring buffer
size definition. Logically, the ring buffer sizes are independent of each other,
and using a common #define implies that they are somehow linked.
Ok, makes sense, let's keep them separate.
--
Vitaly