Re: [PATCH 02/16] hyper-v: trace vmbus_on_message()

Vitaly Kuznetsov
2017-10-04T14:09:51Z

Stephen Hemminger <stephen@networkplumber.org> writes:

> On Thu, 21 Sep 2017 10:17:18 +0200
> Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
>> Steven Rostedt <rostedt@goodmis.org> writes:
>>
>> > On Wed, 20 Sep 2017 19:21:53 +0200
>> > Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>> >
>> >> diff --git a/drivers/hv/hv_trace.h b/drivers/hv/hv_trace.h
>> >> index 9a29ef55477d..72911dfc9682 100644
>> >> --- a/drivers/hv/hv_trace.h
>> >> +++ b/drivers/hv/hv_trace.h
>> >> @@ -14,6 +14,14 @@ TRACE_EVENT(vmbus_on_msg_dpc,
>> >> TP_printk("message %u received", __entry->msgtype)
>> >> );
>> >>
>> >> +TRACE_EVENT(vmbus_on_message,
>> >> + TP_PROTO(const struct vmbus_channel_message_header *hdr),
>> >> + TP_ARGS(hdr),
>> >> + TP_STRUCT__entry(__field(unsigned int, msgtype)),
>> >> + TP_fast_assign(__entry->msgtype = hdr->msgtype),
>> >> + TP_printk("processing message %u", __entry->msgtype)
>> >> + );
>> >
>> > Whenever you have two trace events with everything the same but the
>> > TP_printk(), you can save a little space by using DEFINE_EVENT_PRINT()
>> >
>> > DECLARE_EVENT_CLASS(vmbus_hdr_msg,
>> > TP_PROTO(const struct vmbus_channel_message_header *hdr),
>> > TP_ARGS(hdr),
>> > TP_STRUCT__entry(__field(unsigned int, msgtype),
>> > TP_fast_assign(__entry->msg = hdr->msgtype;),
>> > TP_printk("msgtype=%d", __entry->msgtype)
>> > );
>> >
>> > DEFINE_EVENT_PRINT(vmbus_hdr_msg, vmbus_on_msg_dpc,
>> > TP_PROTO(const struct vmbus_channel_message_header *hdr),
>> > TP_ARGS(hdr),
>> > TP_printk("message %u received", __entry->msgtype));
>> >
>> > DEFINE_EVENT_PRINT(vmbus_hdr_msg, vmbus_on_message,
>> > TP_PROTO(const struct vmbus_channel_message_header *hdr),
>> > TP_ARGS(hdr),
>> > TP_printk("processing message %u", __entry->msgtype));
>> >
>> > This will use the same functions required to save and record the
>> > message but will use a different function to output it to the trace.
>>
>> Oh, thanks! This seems to be useful for
>> vmbus_on_msg_dpc/vmbus_on_message only as all the rest needs to parse
>> different structures. Will use it in v2.
>>
>
> I just used this patch. Since function name is already in the trace message
> no need to have different print's for each one.
>

Sure, will incorporate this into v3.

> From ff85967810c216eb01d181789af4f56bd00dc9b9 Mon Sep 17 00:00:00 2001
> From: Stephen Hemminger <sthemmin@microsoft.com>
> Date: Tue, 3 Oct 2017 09:24:11 -0700
> Subject: [PATCH 3/4] hyperv: fix warnings in trace print
>
> This gets rid of the build warnings from unused printf format.
> And uses common class for print.
> ---
> drivers/hv/hv_trace.h | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/hv/hv_trace.h b/drivers/hv/hv_trace.h
> index be7762955650..4755c4640e39 100644
> --- a/drivers/hv/hv_trace.h
> +++ b/drivers/hv/hv_trace.h
> @@ -11,18 +11,18 @@ DECLARE_EVENT_CLASS(vmbus_hdr_msg,
> TP_ARGS(hdr),
> TP_STRUCT__entry(__field(unsigned int, msgtype)),
> TP_fast_assign(__entry->msgtype = hdr->msgtype;),
> - TP_printk("msgtype=%d", __entry->msgtype)
> + TP_printk("msgtype=%u", __entry->msgtype)
> );
>
> -DEFINE_EVENT_PRINT(vmbus_hdr_msg, vmbus_on_msg_dpc,
> +DEFINE_EVENT(vmbus_hdr_msg, vmbus_on_msg_dpc,
> TP_PROTO(const struct vmbus_channel_message_header *hdr),
> - TP_ARGS(hdr),
> - TP_printk("message %u received", __entry->msgtype));
> + TP_ARGS(hdr)
> +);
>
> -DEFINE_EVENT_PRINT(vmbus_hdr_msg, vmbus_on_message,
> +DEFINE_EVENT(vmbus_hdr_msg, vmbus_on_message,
> TP_PROTO(const struct vmbus_channel_message_header *hdr),
> - TP_ARGS(hdr),
> - TP_printk("processing message %u", __entry->msgtype));
> + TP_ARGS(hdr)
> +);
>
> TRACE_EVENT(vmbus_onoffer,
> TP_PROTO(const struct vmbus_channel_offer_channel *offer),

--
Vitaly