net/hyperv: Add flow control based on hi/low watermark
commit33be96e47cc27f2f1a753a0707b02a73df8c8d46
authorHaiyang Zhang <haiyangz@microsoft.com>
Tue, 27 Mar 2012 13:20:45 +0000 (27 13:20 +0000)
committerDavid S. Miller <davem@davemloft.net>
Tue, 3 Apr 2012 21:47:15 +0000 (3 17:47 -0400)
tree2b0361f4d39a14e2ddd0d23e66656e6174b3cb71
parentede7193d4fdca98178240500d8684dbc139ca26f
net/hyperv: Add flow control based on hi/low watermark

In the existing code, we only stop queue when the ringbuffer is full,
so the current packet has to be dropped or retried from upper layer.

This patch stops the tx queue when available ringbuffer is below
the low watermark. So the ringbuffer still has small amount of space
available for the current packet. This will reduce the overhead of
retries on sending.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/hv/ring_buffer.c
drivers/net/hyperv/netvsc.c
drivers/net/hyperv/netvsc_drv.c
include/linux/hyperv.h