RFR: 8207851 JEP Draft: Support ByteBuffer mapped over non-volatile memory
adinn at redhat.com
Fri Jul 20 13:50:22 UTC 2018
I have finally managed to draft a JEP to formally present the proposal I
circulated a month or two back regarding support for MappedByteBuffer
access to non-volatile memory.
The JEP references a re-implementation of the proposed API:
The rework addresses some of the feedback provided in the initial
(starts in May archive)
(continues into June archive at)
In particular, the re-implementation has split the original Hotspot
intrinsic used to guarantee writeback an address range into 3 intrinsics
relocated into class Unsafe which
write back a single cache line
perform any necessary memory sync pre-writeback
perform any necessary memory sync post-writeback
Also, the implementation has been extended from Linux on x86_64 to also
coater for Linux on AArch64. The latter version compiles and generates
correct code but has not yet been tested because I have not yet obtained
access to a box with a suitably up to date kernel.
Comments and suggestions for improvement would be very welcome.
n.v. Jonathan Halliday is about to get his hands on an x86 box with a
real NVM dimm so we may soon be able to try this out with NVM proper
rather than testing with volatile memory pretending to be NVM.
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