Re: [PATCH v3 0/6] Several changes for the UPIU trace

From: Bean Huo
Date: Mon Dec 14 2020 - 17:38:34 EST


On Mon, 2020-12-14 at 22:13 +0000, Avri Altman wrote:
> Bean Hi,
> I support this series.
> I think it is a good idea to print the response on complete,
> But you need to change the prefix strings, otherwise you are breaking
> the current parsers.
>
> Say that you have a trace log, generated sometime during 2020 using
> the current upiu trace.
> It would look something like:
> "send" <request upiu>
> "complete" <request upiu>
>
> And another log generated sometime during 2021 after your change is
> merged:
> "send" <request upiu>
> "complete" < ****response upiu ****>
>
> The current parser won't be able to differentiate between those logs.
> Just change the prefix strings to be "send_req" and "complete_rsp",
> or something,
> so the parsing tools that support the new format will be able to
> differentiate it from the old one.

Avri,
I still don't understand, this change doesn't break you current parser.
if you still trace "send", "complete", "CDB", "query_send/complte",
they are still there, doesn't change. I suggest you just run on your
system. see if there is conflict.

Regarding your suggestion:
This is not problem now, we just change this definition.

do you mean just "send" and "complete" or all?

#define
UFS_CMD_TRACE_STRINGS \

EM(UFS_CMD_SEND, "send_req") \

EM(UFS_CMD_COMP, "complete_rsp") \

below also need add "req" and "rsp"?


EM(UFS_DEV_COMP, "dev_complete_rsp") \

EM(UFS_QUERY_SEND, "query_send") \

EM(UFS_QUERY_COMP, "query_complete") \

EM(UFS_QUERY_ERR, "query_complete_err") \

EM(UFS_TM_SEND, "tm_send") \

EM(UFS_TM_COMP, "tm_complete") \

EM(UFS_TM_ERR, "tm_complete_err")


>
> Also, once the parser can differentiate the new format from the old,
> whatever follows its fine: cdb / osf / tsf or whatever makes sense to
> you.
>
> Thanks,
> Avri