Messages in this thread |  | | Date | Wed, 18 Dec 2019 12:09:00 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH 1/2] include: trace: Add SCMI header with trace events |
| |
On Mon, Dec 16, 2019 at 05:15:54PM -0500, Jim Quinlan wrote: > From: Lukasz Luba <lukasz.luba@arm.com> > > + > +TRACE_EVENT(scmi_xfer_begin, > + TP_PROTO(u8 id, u8 protocol_id, u16 seq, bool poll), > + TP_ARGS(id, protocol_id, seq, poll), > + > + TP_STRUCT__entry( > + __field(u8, id) > + __field(u8, protocol_id) > + __field(u16, seq) > + __field(bool, poll) > + ), > + > + TP_fast_assign( > + __entry->id = id; > + __entry->protocol_id = protocol_id; > + __entry->seq = seq; > + __entry->poll = poll; > + ), > + > + TP_printk("id=%u protocol_id=%u seq=%u poll=%u", __entry->id, > + __entry->protocol_id, __entry->seq, __entry->poll) > +); > + > +TRACE_EVENT(scmi_xfer_end, > + TP_PROTO(u8 id, u8 protocol_id, u16 seq, u32 status), > + TP_ARGS(id, protocol_id, seq, status), > + > + TP_STRUCT__entry( > + __field(u8, id) > + __field(u8, protocol_id) > + __field(u16, seq) > + __field(u32, status) > + ), > + > + TP_fast_assign( > + __entry->id = id; > + __entry->protocol_id = protocol_id; > + __entry->seq = seq; > + __entry->status = status; > + ), > + > + TP_printk("id=%u protocol_id=%u seq=%u status=%u", __entry->id, > + __entry->protocol_id, __entry->seq, __entry->status) > +); > > Hello, > > When there are multiple messages in the mbox queue, I've found it > a chore matching up the 'begin' event with the 'end' event for each > SCMI msg. The id (command) may not be unique, the proto_id may not be > unique, and the seq may not be unique.
I agree on id and proto_id part easily and the seq may not be unique if and only if the previous command has completed.
> The combination of the three may not be unique.
Not 100% sure on that. I remember one of the issue you reported where OS times out and platform may still be processing it. That's one of the case where seq id may get re-assigned, but now that's fixed and the scenario may not happen. I am trying to understand why you think it is not unique ?
> Would it make sense to assign a monotonically increasing ID to each > msg so that one can easily match the two events for each msg?
I am not sure if we need to maintain a tracker/counter just for trace purposes.
> This id could be the result of an atomic increment and > could be stored in the xfer structure. Of course, it would be one of > the values printed out in the events. > > Also, would you consider a third event, right after the > scmi_fetch_response() invocation in scmi_rx_callback()? I've found > this to be insightful in situations where we were debugging a timeout. > > I'm fine if you elect not to do the above; I just wanted to post > this for your consideration. >
I am interested in the scenario we can make use of this and also help in testing it if we add this. I am not against it but I don't see the need for it.
-- Regards, Sudeep
|  |