@@ -659,6 +659,9 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
* If we cannot write to the ring-buffer; signal the host
* even if we may not have written anything. This is a rare
* enough condition that it should not matter.
+ * NOTE: in this case, the hvsock channel is an exception, because
+ * it looks the host side's hvsock implementation has a throttling
+ * mechanism which can hurt the performance otherwise.
*/
if (channel->signal_policy)
@@ -666,7 +669,8 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
else
kick_q = true;
- if (((ret == 0) && kick_q && signal) || (ret))
+ if (((ret == 0) && kick_q && signal) ||
+ (ret && !is_hvsock_channel(channel)))
vmbus_setevent(channel);
return ret;
When the hvsock channel's outbound ringbuffer is full (i.e., hv_ringbuffer_write() returns -EAGAIN), we should avoid the unnecessary signaling the host. Signed-off-by: Dexuan Cui <decui@microsoft.com> --- drivers/hv/channel.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)