RFR (S): 8181785: Remove the experimental ClearFPUAtPark JVM Flag
Daniel D. Daugherty
daniel.daugherty at oracle.com
Fri Jun 9 15:06:55 UTC 2017
We have removed several experimental options without a CCC/CSR request.
This one is identified as:
experimental(intx, ClearFPUAtPark, 0, "(Unsafe, Unstable)")
Since it is flagged as "Unsafe" and "Unstable" (like one or two I removed
in JDK9), no one should be using it. It will not be noticed or missed.
On 6/9/17 6:36 AM, Robbin Ehn wrote:
> On 06/09/2017 02:27 PM, Thomas Schatzl wrote:
>> Hi Erik,
>> On Thu, 2017-06-08 at 17:04 +0200, Erik Österlund wrote:
>>> There is an experimental JVM flag called ClearFPUAtPark that is used
>>> only by SPARC. It is turned off by default and is marked as Unsafe
>>> The idea is to tell the Solaris kernel not to save floating point
>>> registers when context switching.
>>> I propose to remove it as it is an unstable option. It relies on an
>>> implicit unstable OS contract with the kernel that may or may not be
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8181785
>>> Webrev: http://cr.openjdk.java.net/~eosterlund/8181785/webrev.00/
>>> Testing: JPRT
>>> Will need a sponsor.
>> looks good apart from copyright dates.
>> As even experimental VM options are part of the public VM interface, I
>> think you need to do a CSR request.
>> Further I think we can't just remove these options but need to use the
>> usual option deprecation/removal process.
> Hi, here the runtime process:
> release 1: Deprecate & Handle - warn and keep supporting
> release 2: Deprecate & Obsolete - warn and do nothing
> release 3: Dead - unrecognized
> But in this case I suggest going for 2 directly and let CSR guys
> object if so..
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