From: K. Y. Srinivasan Date: Sat, 1 Dec 2012 14:46:34 +0000 (-0800) Subject: Drivers: hv: Turn off batched reading for util drivers X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=7ae3e035195735f9b6ce3308b6240af877a41ea0;p=deliverable%2Flinux.git Drivers: hv: Turn off batched reading for util drivers Util driver is not a performance critical driver and furthermore some util services such as KVP can only handle one outstanding message from the host. Turn off batched reading for util drivers. Signed-off-by: K. Y. Srinivasan Reviewed-by: Haiyang Zhang Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index a0667de7a04c..a62a76062508 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -274,6 +274,16 @@ static int util_probe(struct hv_device *dev, } } + /* + * The set of services managed by the util driver are not performance + * critical and do not need batched reading. Furthermore, some services + * such as KVP can only handle one message from the host at a time. + * Turn off batched reading for all util drivers before we open the + * channel. + */ + + set_channel_read_state(dev->channel, false); + ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0, srv->util_cb, dev->channel); if (ret)