Drivers: hv: util: Make hv_poll_channel() a little more efficient

The current code unconditionally sends an IPI. If we are running on the
correct CPU and are in interrupt level, we don't need an IPI.
Make this adjustment.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 6113e915c50e7b958433e2e7353e291cedfb6e6e..fa514be7679c9e0ff60ec167db84b30b4f79c036 100644 (file)
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -411,6 +411,10 @@ static inline void hv_poll_channel(struct vmbus_channel *channel,
        if (!channel)
                return;
 
+       if (in_interrupt() && (channel->target_cpu == smp_processor_id())) {
+               cb(channel);
+               return;
+       }
        smp_call_function_single(channel->target_cpu, cb, channel, true);
 }