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

[David Holmes]

On 17/10/2018 10:19 AM, coleen.phillimore at oracle.com wrote:
> On 10/16/18 7:52 PM, David Holmes 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?
> 
> Since we've never acted upon these flags, I think it's better to leave 
> them in as is, and not obsolete them just for bsd in the table.  If 
> people have linux scripts that they're using on macos (doubtful but 
> maybe), they'll get new messages that break their scripts.

Yes and that is why we have a deprecation/obsoletion process. The intent 
is to give them a message so they fix their scripts. We don't silently 
accept flags that serve no purpose.

Thanks,
David

> thanks,
> Coleen
> 
>>
>> 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.
>>
>>>>> Also, in this fix, I took opportunity to cleanup OS includes (there 
>>>>> were unused and duplicated headers)
>>>>
>>>> Seems mostly okay but I would have expected mach/mach.h, or 
>>>> mach/mach_time.h, to get mach_timebase_info_data_t ? Maybe it comes 
>>>> in indirectly from elsewhere? I poked around the devkit but couldn't 
>>>> isolate it.
>>>
>>> It comes from:
>>>
>>> #include “os_bsd.inline.hpp”
>>>    #include “runtime/os.hpp”
>>>      #idef __APPLE__
>>>      #include <mach/mach_time.h>
>>>      #endif
>>
>> Okay.
>>
>> Thanks,
>> David
>>
>>>
>>> cheers
>>>
>