Order of entries in make/mapfiles/reorder-*

Claes Redestad claes.redestad at oracle.com
Fri Dec 8 15:32:06 UTC 2017

I think the tool to generate these reorder files exist under 
src/utils/reorder, but looking at
src/utils/reorder/Makefile it seems to have bit-rotted over the years.. 
the bootclasspath tricks
with rt.jar etc likely won't even work today:

# This Makefile is intended to produce new reordering files for the
# reordering of jar files and shared libraries.  This is not part of the
# standard build.  The objects produced by this Makefile must be copied
# into their standard locations and checked in.

I'm not sure any of this is relevant in the modular world (as most jar 
files are now merged
into lib/modules, which has a separate reordering facility that is 
automatically generated on
build and enforced by jlink).

File a bug to investigate and potentially remove it all?


On 2017-12-08 10:53, Magnus Ihse Bursie wrote:
> On 2017-12-08 07:26, David Holmes wrote:
>> Nobody?
> I don't know. They existed long time before I started working on the 
> build system. I believe they were an attempt to optimize the layout 
> based on some test that ran years and years ago. It's likely that they 
> do nothing (at best) or worsen performance (at worst).  Very few 
> libraries has these reorder files any more. If you think you need to 
> update one, I think a reasonable course of action is to remove it 
> instead.
> Maybe Claes can help me confirm my speculation about performance..?
> /Magnus
>> On 7/12/2017 8:15 PM, David Holmes wrote:
>>> I have to add new entries to the mapfiles. How is the order in the 
>>> reorder-* files determined?
>>> Thanks,
>>> David

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