Request for review 8005075: CDS archive with one alignment causes crash when run with different alignment

harold seigel harold.seigel at
Tue Dec 18 11:58:13 PST 2012

Please review the modified fix for bug 8005076.  The modified fix can be 
viewed at 

It contains two changes from the previous fix.

As requested by Vitaly, the diagnostic in filemap.cpp has been changed 
to include the incompatible ObjectAlignmentInBytes values.  Here's 
sample new message:

    The shared archive file's ObjectAlignmentInBytes of 8 is too small
    for the current ObjectAlignmentInBytes of 16.

Also, the change to arguments.cpp no longer sets a minimum value for 
-XX:+ObjectAlignmentInBytes.  (This was requested by Coleen.)

Thanks, Harold

On 12/17/2012 7:10 PM, Vitaly Davidovich wrote:
> Hi Harold,
> It might be useful to report the recorded alignment in the CDS archive 
> in the diagnostic message that you print out.  What do you think?
> Thanks
> Sent from my phone
> On Dec 17, 2012 10:24 AM, "harold seigel" <harold.seigel at 
> <mailto:harold.seigel at>> wrote:
>     Please review the following change to fix bug 8005075.
>     Summary:  This change prevents a crash when a CDS archive is
>     created with a value for -XX:+ObjectAlignmentInBytes that is
>     smaller than the ObjectAlignmentInBytes value used when running
>     with -Xshare:on.  This fix stores the ObjectAlignmentInBytes in
>     the CDS archive so that when the archive is read, hotspot can
>     compare the archive's alignment with the current alignment and
>     issue the following diagnostic if the archive's alignment is too
>     small:
>         An error has occurred while processing the shared archive file.
>         The shared archive file was created with a smaller Object
>         Alignment value.
>     This webrev also cleans up some text in globals.hpp and fixes a
>     small problem with -XX:SharedReadOnlySize.  The existing code was
>     always setting SharedReadOnlySize to 14M regardless of what was
>     requested.  This prevented users from being able to expand the CDS
>     archive's SharedReadOnly section.
>     Open webrev at
>     <>
>     Bug link at
>     The changes were tested with JCK, JPRT, JTREG, and UTE tests, and
>     with hand-run tests using different ObjectAlignmentInBytes values.
>     Thanks, Harold
-------------- next part --------------
An HTML attachment was scrubbed...

More information about the hotspot-runtime-dev mailing list