Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion

Allocate ring buffer memory from the NUMA node assigned to the channel.
Since this is a performance and not a correctness issue, if the node specific
allocation were to fail, fall back and allocate without specifying the node.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/channel.c

@@ -73,6 +73,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	unsigned long flags;
 	int ret, err = 0;
 	unsigned long t;
+	struct page *page;
 
 	spin_lock_irqsave(&newchannel->lock, flags);
 	if (newchannel->state == CHANNEL_OPEN_STATE) {
@@ -87,8 +88,17 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	newchannel->channel_callback_context = context;
 
 	/* Allocate the ring buffer */
+	page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
+				GFP_KERNEL|__GFP_ZERO,
+				get_order(send_ringbuffer_size +
+				recv_ringbuffer_size));
+
+	if (!page)
 		out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
-		get_order(send_ringbuffer_size + recv_ringbuffer_size));
+					       get_order(send_ringbuffer_size +
+					       recv_ringbuffer_size));
+	else
+		out = (void *)page_address(page);
 
 	if (!out) {
 		err = -ENOMEM;