RFR: 8154791: Xlog classload too redundant msgs info/debug

David Holmes david.holmes at oracle.com
Wed May 11 01:09:51 UTC 2016


On 11/05/2016 2:55 AM, Max Ockner wrote:
> Thanks for the responses.
>
> (1) classFileParser.cpp missing conditional
>
> This provides a better view:
> http://cr.openjdk.java.net/~mockner/8154791.02/src/share/vm/classfile/classFileParser.cpp.sdiff.html
>
>
> Here is the surrounding code:
>     if (log_is_enabled(Info, class, load)) {
>       ResourceMark rm;
>       const char* module_name = NULL;
>       static const size_t modules_image_name_len =
> strlen(MODULES_IMAGE_NAME);
>       size_t stream_len = strlen(_stream->source());
>       // See if _stream->source() ends in "modules"
>       if (module_entry->is_named() && modules_image_name_len <
> stream_len &&
>         (strncmp(_stream->source() + stream_len - modules_image_name_len,
>                  MODULES_IMAGE_NAME, modules_image_name_len) == 0)) {
>         module_name = module_entry->name()->as_C_string();
>       }
>       ik->print_loading_log(_loader_data, module_name, _stream);
>     }
>
> The log_is_enabled conditional has always been there at the top. The
> conditionals at the bottom (which have been removed) were used to
> differentiate between info and debug cases. Since there is no debug
> level for class,load now, we can remove these conditionals.

Ah! Thanks.

David

> (2) Snippet of output
>
> This is what we used to have for debug level logging:
> [0.027s][info][class,load] java.lang.Object source: jrt:/java.base
> [0.027s][debug][class,load] java.lang.Object source: jrt:/java.base
> klass: 0x00000007c0000fb0 super: 0x0000000000000000 loader: [NULL
> class_loader] bytes: 1859 checksum: 8833820d
>
> This is what we now have for info level logging:
> [0.023s][info][class,load] java.lang.Object source: jrt:/java.base
> klass: 0x00000007c0000fb0 super: 0x0000000000000000 loader: [NULL
> class_loader] bytes: 1859 checksum: 8833820d
>
> There is no longer any debug level logging for class,load
>
> Thanks,
> Max
>
> On 5/10/2016 3:45 AM, David Holmes wrote:
>> On 10/05/2016 12:56 PM, Ioi Lam wrote:
>>> Max,
>>>
>>> Does this mean that the class loading log is always printed. Or at
>>> least, all the formatting in instanceKlass::print_loading_log() is done
>>> and the stuff is printed to a NULL stream?
>>
>> That's what I was wondering too - the call in
>> src/share/vm/classfile/classFileParser.cpp is unconditional.
>>
>> David
>>
>>> classFileParser.cpp:
>>>
>>>     ik->print_loading_log(_loader_data, module_name, _stream);
>>>
>>> InstanceKlass::print_loading_log(...) {
>>>   outputStream* log = Log(class, load)::info_stream();
>>>   // Name and class hierarchy info
>>>   log->print("%s", external_name());
>>>   ...
>>> }
>>>
>>> I think you should add a quick test in print_loading_log() and return if
>>> (class, load) is not enabled.
>>>
>>> As usual, it would be helpful for the reviewers if you can include a
>>> small sample of the output (before and after).
>>>
>>> Thanks
>>> - Ioi
>>>
>>> On 5/9/16 12:06 PM, Coleen Phillimore wrote:
>>>>
>>>> Max, This looks a lot nicer.
>>>> Thanks,
>>>> Coleen
>>>>
>>>>
>>>> On 5/9/16 2:43 PM, Max Ockner wrote:
>>>>> Hello,
>>>>>
>>>>> Please review this small change to logging for class loading.
>>>>>
>>>>> Webrev: http://cr.openjdk.java.net/~mockner/8154791.02/
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8154791
>>>>>
>>>>> -Xlog:class+load=debug used to produce redundant info. Some of the
>>>>> debug level lines were nearly identical to some of the info level
>>>>> lines. To reduce the redundant information, these debug messages have
>>>>> been moved into the info level, replacing the corresponding info
>>>>> messages.
>>>>>
>>>>> Tested with jtreg runtime.
>>>>>
>>>>> I can wait to submit this until after the FC deadline.
>>>>>
>>>>> Thanks,
>>>>> Max
>>>>
>>>
>


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