vmbus: change to per channel tasklet
Make the event handling tasklet per channel rather than per-cpu.
This allows for better fairness when getting lots of data on the same
cpu.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 158f128..27e72dc 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -260,29 +260,6 @@ void vmbus_disconnect(void)
}
/*
- * Map the given relid to the corresponding channel based on the
- * per-cpu list of channels that have been affinitized to this CPU.
- * This will be used in the channel callback path as we can do this
- * mapping in a lock-free fashion.
- */
-static struct vmbus_channel *pcpu_relid2channel(u32 relid)
-{
- struct hv_per_cpu_context *hv_cpu
- = this_cpu_ptr(hv_context.cpu_context);
- struct vmbus_channel *found_channel = NULL;
- struct vmbus_channel *channel;
-
- list_for_each_entry(channel, &hv_cpu->chan_list, percpu_list) {
- if (channel->offermsg.child_relid == relid) {
- found_channel = channel;
- break;
- }
- }
-
- return found_channel;
-}
-
-/*
* relid2channel - Get the channel object given its
* child relative id (ie channel id)
*/
@@ -318,25 +295,16 @@ struct vmbus_channel *relid2channel(u32 relid)
}
/*
- * process_chn_event - Process a channel event notification
+ * vmbus_on_event - Process a channel event notification
*/
-static void process_chn_event(u32 relid)
+void vmbus_on_event(unsigned long data)
{
- struct vmbus_channel *channel;
+ struct vmbus_channel *channel = (void *) data;
void *arg;
bool read_state;
u32 bytes_to_read;
/*
- * Find the channel based on this relid and invokes the
- * channel callback to process the event
- */
- channel = pcpu_relid2channel(relid);
-
- if (!channel)
- return;
-
- /*
* A channel once created is persistent even when there
* is no driver handling the device. An unloading driver
* sets the onchannel_callback to NULL on the same CPU
@@ -344,7 +312,6 @@ static void process_chn_event(u32 relid)
* Thus, checking and invoking the driver specific callback takes
* care of orderly unloading of the driver.
*/
-
if (channel->onchannel_callback != NULL) {
arg = channel->channel_callback_context;
read_state = channel->batched_reading;
@@ -373,45 +340,6 @@ static void process_chn_event(u32 relid)
}
/*
- * vmbus_on_event - Handler for events
- */
-void vmbus_on_event(unsigned long data)
-{
- struct hv_per_cpu_context *hv_cpu = (void *)data;
- unsigned long *recv_int_page;
- u32 maxbits, relid;
-
- if (vmbus_proto_version < VERSION_WIN8) {
- maxbits = MAX_NUM_CHANNELS_SUPPORTED;
- recv_int_page = vmbus_connection.recv_int_page;
- } else {
- /*
- * When the host is win8 and beyond, the event page
- * can be directly checked to get the id of the channel
- * that has the interrupt pending.
- */
- void *page_addr = hv_cpu->synic_event_page;
- union hv_synic_event_flags *event
- = (union hv_synic_event_flags *)page_addr +
- VMBUS_MESSAGE_SINT;
-
- maxbits = HV_EVENT_FLAGS_COUNT;
- recv_int_page = event->flags;
- }
-
- if (unlikely(!recv_int_page))
- return;
-
- for_each_set_bit(relid, recv_int_page, maxbits) {
- if (sync_test_and_clear_bit(relid, recv_int_page)) {
- /* Special case - vmbus channel protocol msg */
- if (relid != 0)
- process_chn_event(relid);
- }
- }
-}
-
-/*
* vmbus_post_msg - Send a msg on the vmbus's message connection
*/
int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
