Re: [PATCH 10/17] hyper-v: trace vmbus_open()

[Greg KH]

On Sun, Oct 29, 2017 at 12:21:09PM -0700, kys@xxxxxxxxxxxxxxxxxxxxxx wrote:
> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> 
> Add tracepoint to CHANNELMSG_OPENCHANNEL sender.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> ---
>  drivers/hv/channel.c  |  2 ++
>  drivers/hv/hv_trace.h | 27 +++++++++++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
> index a406beb10dd0..739b3fe1e0fb 100644
> --- a/drivers/hv/channel.c
> +++ b/drivers/hv/channel.c
> @@ -185,6 +185,8 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
>  	ret = vmbus_post_msg(open_msg,
>  			     sizeof(struct vmbus_channel_open_channel), true);
>  
> +	trace_vmbus_open(open_msg, ret);

Why add tracepoints for things that ftrace can handle automatically?