lkml.org 
[lkml]   [2011]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/4] Staging: hv: vmbus: Check for events before messages
Date
The Windows team has informed us that on Windows guests on Hyper-V,
they check for events before messages. They also recommended that we do
the same. This patch addresses this.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/vmbus_drv.c | 22 ++++++++++++++--------
1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/hv/vmbus_drv.c b/drivers/staging/hv/vmbus_drv.c
index b5e06d6..cd43ddd 100644
--- a/drivers/staging/hv/vmbus_drv.c
+++ b/drivers/staging/hv/vmbus_drv.c
@@ -442,14 +442,11 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
union hv_synic_event_flags *event;
bool handled = false;

- page_addr = hv_context.synic_message_page[cpu];
- msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
-
- /* Check if there are actual msgs to be process */
- if (msg->header.message_type != HVMSG_NONE) {
- handled = true;
- tasklet_schedule(&msg_dpc);
- }
+ /*
+ * Check for events before checking for messages. This is the order
+ * in which events and messages are checked in Windows guests on
+ * Hyper-V, and the Windows team suggested we do the same.
+ */

page_addr = hv_context.synic_event_page[cpu];
event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
@@ -460,6 +457,15 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
tasklet_schedule(&event_dpc);
}

+ page_addr = hv_context.synic_message_page[cpu];
+ msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
+
+ /* Check if there are actual msgs to be processed */
+ if (msg->header.message_type != HVMSG_NONE) {
+ handled = true;
+ tasklet_schedule(&msg_dpc);
+ }
+
if (handled)
return IRQ_HANDLED;
else
--
1.7.4.1


\
 
 \ /
  Last update: 2011-08-31 23:17    [W:0.039 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site