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linuxkit/kernel/patches-4.4/0028-Drivers-hv-vmbus-vmbus_sendpacket_ctl-hvsock-avoid-u.patch
Rolf Neugebauer 201f89de74 kernel: Update to 4.10.9/4.9.21/4.4.60
Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
2017-04-09 22:50:18 +01:00

46 lines
1.6 KiB
Diff

From 99ee6a24b16eb6db124d0fafebb1b87bbf1f3dc6 Mon Sep 17 00:00:00 2001
From: Dexuan Cui <decui@microsoft.com>
Date: Wed, 27 Jan 2016 22:29:39 -0800
Subject: [PATCH 28/44] Drivers: hv: vmbus: vmbus_sendpacket_ctl: hvsock: avoid
unnecessary signaling
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>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 5f363bc38f810d238d1e8b19998625ddec3b8138)
---
drivers/hv/channel.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index dd6de7fc442f..128dcf22e459 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -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;
--
2.11.1