Enabling non product flags like "Verbose" in GC Code

suraj puvvada suraj.puvvada at gmail.com
Thu Aug 25 14:34:31 PDT 2011


Thanks.

Are the non-product builds available online to download ?

-Suraj

On Thu, Aug 25, 2011 at 1:37 PM, Ramki Ramakrishna <
y.s.ramakrishna at oracle.com> wrote:

> **
> Hi Suraj --
>
> Either:
>
> (1) use a non-product build where the flag is available, OR
>
> (2) rebuild with Verbose declared a product flag (but you will have to deal
> with
>      develop->product contagion which will require more such changes), OR
>
> (3) (probably the easiest in a specific product build) rebuild with Verbose
> changed to
>       a new product flag of your choice for the specific sites where you
> want to print the info
>       but want to retain the option of turning it off. Depending on where
> you do this, this
>       may also cause a develop->product contagion, but it will be a more
> controlled burn, if
>       i may be allowed to mix my metaphors.
>
> (..) anything else?
>
> The above are all one-off's for use in a specific build.
>
> There may be good reason to protect some of these more useful messages with
> a product
> flag rather than with a develop flag. I recall Krystal Mok also mentioning
> something similar.
> Perhaps the community can work on what are the kinds of messages one might
> want to
> see in production (under control of a suitable manageable/product flag),
> and submit an OpenJDK
> patch with those changes (hopefully the performance impact of the check or
> enablement
> will be minor enough when these changes are for example communicating
> ergonomic
> decisions etc. -- this should of course be performance checked before a
> patch is submitted).
>
> I'm also hoping that in the future some of these may be captured by the
> logging framework
> under construction. Those working on or planning to work on the logging
> framework may hav
>  more to add. So I am cc'ing the serviceability alias as well.
>
> -- ramki
>
>
> On 8/25/2011 12:58 PM, suraj puvvada wrote:
>
> Hi,
>
> How can I enable DEVELOP mode flags like "Verbose" ? I'm interested in
> seeing what the GC code logs - for example :
>
> if (PrintGCDetails && Verbose) {
>       gclog_or_tty->print_cr("ConcurrentMarkSweepGeneration::shrink_by:"
>         " desired_bytes " SIZE_FORMAT
>         " shrinkable_size_in_bytes " SIZE_FORMAT
>         " aligned_shrinkable_size_in_bytes " SIZE_FORMAT
>         "  bytes  " SIZE_FORMAT,
>         desired_bytes, shrinkable_size_in_bytes,
>         aligned_shrinkable_size_in_bytes, bytes);
>       gclog_or_tty->print_cr("          old_end  " SIZE_FORMAT
>         "  unallocated_start  " SIZE_FORMAT,
>         old_end, unallocated_start);
>     }
>
>
> -Suraj
>
>
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