RFR(xs): 8150619: Improve thread based logging introduced with 8149036

[Thomas Stüfe]

Hi David,


>>              Okay I'm confused - I thought the whole point of using
>>         os+thread
>>              here was that you had to enable os _and_ thread level
>>         logging ???
>>              Else why bother using the two? I would not have expected
>>         the above
>>              to work! :(
>>
>>
>>         No, the logging line is just tagged with both keywords. As far as
>> I
>>         understand multiple tags in UL there is no way to specify
>> conditions
>>         like "&&" or "||" - you just tag them - and specifying rules
>>         happens on
>>         the command line with "os+thread" or "os,thread". So all of
>>         this: "os*",
>>         "thread*", "os+thread" should produce an output, the last one
>>         will stop
>>         producing output as soon as someone adds a third tag to the
>>         logging calls.
>>
>>
>>     I thought "os,thread" meant os _and_ thread not os _or_ thread.
>>     Having "thread*" enable this particular logging is very unintuitive
>>     to me - though "*thread" might make some sense.
>>
>>
>> I do not understand what you mean with "*thread".
>>
>
> I was considering the ordering of tags to be significant - which as Markus
> points out it is not. So I did not expect "thread*" to match "os,thread" -
> but I would have considered "*thread" a match :)


Ah, now I get you.


>
>
> When marking these log lines with "os" and "thread", I may either
>>
>> - enable "os*" and see all these log lines and anything else marked with
>> "os" - aka "anything os-related"
>> - enable "thread*" and see all these log lines and anything else marked
>> with "thread" - aka "anything thread related"
>> - enable "os+thread" and see only these log lines - aka "anything thread
>> related at os level"
>>
> >
>
>> Not sure why you find this unintuitive?
>>
>
> I was considering "os,thread" to form a "thread" namespace within the "os"
> namespace and so to see "os,thread" you had to first enable the "os" part.
>
>
No, I was just enumerating keywords.

I think UL just gives as tags and what we do with them is up to us (which
may be a problem, because there seems to be no standard). I think the GC
people use tags hierarchically: with "gc" is the outside scope and all
their other tags inner scope. But I thought they are the exception, all
other tags seem to be plain keywords.

Kind Regards, Thomas



> Cheers,
> David
>
>
> Kind Regards, Thomas
>>
>>     Thanks,
>>     David
>>     -----
>>
>>
>>         Note that I added the "thread" keyword because Marcus requested
>>         this:
>>
>> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-February/018154.html
>>
>>         But I simplified the test to test once for "os+thread" instead
>>         of each
>>         tag separately. Note that with this change, the test will have to
>> be
>>         modified if someone adds a third tag.
>>
>>
>>              FYI the test passed on our JPRT system.
>>
>>
>>         Great, thanks.
>>
>>         Thank you,
>>
>>         Thomas
>>
>>              Thanks,
>>              David
>>
>>
>>                  Thanks & Kind Regards, Thomas
>>
>>
>>
>>