[PATCH 4/6] Drivers: hv: util: Make hv_poll_channel() a little more efficient

[kys]

From: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
 drivers/hv/hyperv_vmbus.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 6113e91..fa514be 100644
--- 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);
 }
 
-- 
1.7.1