hv_balloon: Use a static page for the balloon_up send buffer

It's unnecessary to dynamically allocate the buffer.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 6fb4ea5..4b06f07 100644 (file)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -494,7 +494,7 @@ enum hv_dm_state {
 
 
 static __u8 recv_buffer[PAGE_SIZE];
-static __u8 *send_buffer;
+static __u8 balloon_up_send_buffer[PAGE_SIZE];
 #define PAGES_IN_2M    512
 #define HA_CHUNK (32 * 1024)
 
@@ -1292,8 +1292,8 @@ static void balloon_up(struct work_struct *dummy)
        }
 
        while (!done) {
-               bl_resp = (struct dm_balloon_response *)send_buffer;
-               memset(send_buffer, 0, PAGE_SIZE);
+               memset(balloon_up_send_buffer, 0, PAGE_SIZE);
+               bl_resp = (struct dm_balloon_response *)balloon_up_send_buffer;
                bl_resp->hdr.type = DM_BALLOON_RESPONSE;
                bl_resp->hdr.size = sizeof(struct dm_balloon_response);
                bl_resp->more_pages = 1;
@@ -1578,19 +1578,11 @@ static int balloon_probe(struct hv_device *dev,
        do_hot_add = false;
 #endif
 
-       /*
-        * First allocate a send buffer.
-        */
-
-       send_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
-       if (!send_buffer)
-               return -ENOMEM;
-
        ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0,
                        balloon_onchannelcallback, dev);
 
        if (ret)
-               goto probe_error0;
+               return ret;
 
        dm_device.dev = dev;
        dm_device.state = DM_INITIALIZING;
@@ -1716,8 +1708,6 @@ probe_error2:
 
 probe_error1:
        vmbus_close(dev->channel);
-probe_error0:
-       kfree(send_buffer);
        return ret;
 }
 
@@ -1736,7 +1726,6 @@ static int balloon_remove(struct hv_device *dev)
 
        vmbus_close(dev->channel);
        kthread_stop(dm->thread);
-       kfree(send_buffer);
 #ifdef CONFIG_MEMORY_HOTPLUG
        restore_online_page_callback(&hv_online_page);
        unregister_memory_notifier(&hv_memory_nb);