RFR 8017061: os_bsd.cpp contains code for UseSHM and UseHugeTLBFS

[David Holmes]

Hi Gerard,

src/hotspot/os/bsd/globals_bsd.hpp

You've introduced an extra space in the copyright notice:

!  * ANY WARRANTY; without even  the implied warranty of MERCHANTABILITY or

Otherwise all good.

Thanks,
David


On 23/10/2018 2:27 AM, Gerard Ziemski wrote:
> 
>> On Oct 18, 2018, at 8:24 PM, David Holmes <david.holmes at oracle.com> wrote:
>>
>> On 18/10/2018 11:35 PM, Gerard Ziemski wrote:
>>>> On Oct 17, 2018, at 8:38 PM, David Holmes <david.holmes at oracle.com> wrote:
>>>>
>>>> Hi Gerard,
>>>>
>>>> On 18/10/2018 3:14 AM, Gerard Ziemski wrote:
>>>>> Thank you for your reviews.
>>>>>> On Oct 16, 2018, at 6:52 PM, David Holmes <david.holmes at oracle.com> wrote:
>>>>>>
>>>>>> Hi Gerard,
>>>>>>
>>>>>> On 17/10/2018 2:04 AM, Gerard Ziemski wrote:
>>>>>>> hi David,
>>>>>>> Thank you for the review.
>>>>>>>> On Oct 16, 2018, at 1:48 AM, David Holmes <david.holmes at oracle.com> wrote:
>>>>>>>>
>>>>>>>> Hi Gerard,
>>>>>>>>
>>>>>>>> On 16/10/2018 5:41 AM, Gerard Ziemski wrote:
>>>>>>>>> Hi all,
>>>>>>>>> Please review this small fox that removes code from bsd platform, which implements unused (and untested) UseLargePages support.
>>>>>>>>
>>>>>>>> Removal seems okay but I think you can also remove:
>>>>>>>>
>>>>>>>> ./os/bsd/globals_bsd.hpp:  product(bool, UseSHM, false,
>>>>>>>> ./os/bsd/globals_bsd.hpp:  product(bool, UseHugeTLBFS, false,
>>>>>>> If I remove “UseSHM” and “UseHugeTLBFS” they will stop being accepted on BSD platform, though the documentation says it’s Linux only. Would I need to obsolete them? If so, how to obsolete a flag on just one platform?
>>>>>>
>>>>>> I think if you #ifdef the entry in the obsolete flags table that would do it. This is a rare occurrence. Obsolete in 12 and expire in 13.
>>>>> Fixed.
>>>>> Webrev: http://cr.openjdk.java.net/~gziemski/8017061_rev2
>>>>
>>>> The flags are obsoleted not deprecated, they should be removed from the globals_bsd.hpp file.
>>> If I remove them, then VM will no longer accept them and refuse to run. I though that the purpose of the deprecate/obsolete/expire exercise is to allow the VM to accept the flags in question, so developers have the time to adapt, and only remove them later?
>>
>> You don't understand the deprecation/obsoletion/expiration process.
>>
>> Deprecation:
>> - the code using the flag exists and works as normal
>> - the flag continues to exist in globals.hpp (or variants)
>> - the flag is listed as deprecated in the arguments.cpp table, for the current version, and may have future obsoletion and expiration versions
>> - if the flag is used then a deprecation warning is issued
>>
>> Obsoletion:
>> - the code using the flag is completely removed (assuming the flags default value if appropriate)
>> - the flag is removed from globals.hpp (or variants)
>> - the table in arguments.cpp lists the flag as obsoleted in the current release
>> - if the flag is used then an obsoletion warning is issued
>>
>> Expiration
>> - the flag is removed from the table in arguments.cpp
>> - if the flag is used the VM terminates with an "unknown VM option" error
> 
> Thank you for the explanations.
> 
> Webrev: http://cr.openjdk.java.net/~gziemski/8017061_rev3
> Testing: Mach5 hs_tier1-6 (in progress…)
> 
> 
> cheers
>