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

[harold seigel]

Please review the modified fix for bug 8005076.  The modified fix can be 
viewed at http://cr.openjdk.java.net/~hseigel/bug_8005076_2/ 
<http://cr.openjdk.java.net/%7Ehseigel/bug_8005076_2/>

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 oracle.com 
> <mailto:harold.seigel at oracle.com>> 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 http://cr.openjdk.java.net/~hseigel/bug_8005076/
>     <http://cr.openjdk.java.net/%7Ehseigel/bug_8005076/>
>
>     Bug link at http://bugs.sun.com/view_bug.do?bug_id=8005076
>
>     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...
URL: http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/attachments/20121218/f66f6622/attachment.html