RFR(xxs): 8241395: Factor out platform independent code for os::xxx_memory_special()

[Doerr, Martin]

Hi Thomas,

looks good to me, too.

In addition to the copyright, please improve indentation for the 2nd argument line in os_linux.cpp and os_windows.cpp:
+char* os::pd_reserve_memory_special(size_t bytes, size_t alignment,
                                  char* req_addr, bool exec) {

and remove extra newline in os.cpp:
+   return result;
+ 
+ }

No need for a new webrev.

Best regards,
Martin


> -----Original Message-----
> From: hotspot-runtime-dev <hotspot-runtime-dev-
> bounces at openjdk.java.net> On Behalf Of Baesken, Matthias
> Sent: Dienstag, 24. März 2020 16:25
> To: Thomas Stüfe <thomas.stuefe at gmail.com>; hotspot-runtime-
> dev at openjdk.java.net
> Subject: RE: RFR(xxs): 8241395: Factor out platform independent
> code for os::xxx_memory_special()
> 
> Hi Thomas, looks good to me.
> But you might want to change the copyright year in
> 
> http://cr.openjdk.java.net/~stuefe/webrevs/8241395-refactor-reserve-
> memory-
> special/webrev.00/webrev/src/hotspot/share/runtime/os.hpp.frames.html
> 
> Thanks, Matthias
> 
> ---------- Forwarded message ---------
> From: Thomas Stüfe
> <thomas.stuefe at gmail.com<mailto:thomas.stuefe at gmail.com>>
> Date: Sat, Mar 21, 2020 at 1:40 PM
> Subject: RFR(xxs): 8241395: Factor out platform independent code for
> os::xxx_memory_special()
> To: Hotspot dev runtime <hotspot-runtime-
> dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net>>
> 
> Hi,
> 
> may I please have reviews for this little cleanup.
> 
> A while ago we factored out platform independent behavior for
> os::reserve_memory() and friends to os.cpp and relegated platform
> dependent code to os::pd_reserve_memory() etc. This change does the
> same for os::reserve_memory_special() and os::release_memory_special().
> 
> Only Linux and Windows are affected since only they have meaningful
> implementations for UseLargePages.
> 
> It also adds a small comment about the NMT Tracker object.
> 
> In addition it asserts - now for all platforms, it used to do this only on Linux -
> that if both requested address and alignment are given to
> os::reserve_memory_special() the requested address should at least be
> aligned to the given alignment (the arguments should be mutually exclusive
> and I plan to clean this up further).
> 
> Issue: https://bugs.openjdk.java.net/browse/JDK-8241395
> webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8241395-refactor-
> reserve-memory-special/webrev.00/webrev/
> 
> Thanks, Thomas