RFR (M): 8077144: Concurrent mark initialization takes too long

Thomas Schatzl thomas.schatzl at oracle.com
Tue Mar 29 09:06:46 UTC 2016


Hi,

On Fri, 2016-03-25 at 21:48 -0400, Kim Barrett wrote:
> > On Mar 25, 2016, at 9:38 PM, Kim Barrett <kim.barrett at oracle.com>
> > wrote:
> > 
> > > On Mar 15, 2016, at 6:12 PM, Thomas Schatzl <
> > > thomas.schatzl at oracle.com> wrote:
> > > 
> > > Hi Mikael,
> > > 
> > > updated webrev at
> > > http://cr.openjdk.java.net/~tschatzl/8077144/webrev.3/ (full)
> > > http://cr.openjdk.java.net/~tschatzl/8077144/webrev.2_to_3/ (diff
> > > )
> > > 
> > > which implements the suggested changes.
> > 
> > src/share/vm/utilities/bitMap.hpp
> > 147   static idx_t size_in_words(size_t size_in_bits) {
> > 
> > I find the name of this function confusing in conjunction with the
> > no-arg ordinary member function; I'm not keen on overloads with
> > with
> > very different semantics and usage. Clearer (to me) here might be
> > something like calc_size_in_words.
> 
> The existing BitMap::word_align_up could be used instead of
> introducing this new function.

  I am not sure if that function helps in an as concise way as
calc_size_in_words().

I.e. do you suggest to use word_align_up(size())? Then I could as well
use size_in_bytes() and divide by sizeof(bm_word_t). (by other
alignment/size constraints a per-region part must always be word
-aligned).

There has been a particular (non-public) request to be specific with
sizes in these changes.

Or do you mean, use word_align_up() in calc_size_in_words()?

Thanks for the clarification,
  Thomas



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